Galactic Habitable Zone

One of our Sun’s unusual features is its orbit around the center of the galaxy, which is significantly less elliptical (“eccentric”) than those of other stars similar in age (and therefore metallicity, or proportion of an object’s chemical composition other than hydrogen and helium) and type and is barely inclined relative to the Galactic plane. This circularity in the Sun’s orbit prevents it from plunging into the inner Galaxy where life-threatening supernovae are more common. Moreover, the small inclination to the galactic plane avoids abrupt crossings of the plane that would stir up the Sun’s Oort Cloud and bombard the Earth with life-threatening comets.

In fact, the Sun is orbiting very close to the “co-rotation radius” of the galaxy, where the angular speed of the galaxy’s spiral arms matches that of the stars within. As a result, the Sun avoids crossing the spiral arms very often, which would expose Earth to supernovae that are more common there. These exceptional circumstances may have made it more likely for complex life and human intelligence to emerge on Earth. According to Guillermo Gonzalez (an astronomer at Iowa State University), fewer than five percent of all stars in the galaxy enjoy such a life-enhancing galactic orbit. Other astronomers point out, however, that many nearby stars move with the Sun in a similar galactic orbit.

The Sun resides in a pancake region of the Galaxy called the “disk” with a strong concentration of stars (and gas and dust) within 3,000 light-years (ly) of the galactic plane, which includes the so-called “thin disk” that has more relatively younger stars within 1,500 ly of the plane (more on stellar population groups in our Milky Way Galaxy). This region contains relatively young to intermediate-aged stars that within around five billion years old with relatively higher average metallicity than other galactic regions located outside of the galactic core, in a circular band that broadens with time. Generated by the deaths of older stars, the greater availability of elements higher than hydrogen and helium in this galactic region favor the formation of rocky inner planets as large as Earth, or bigger (Gonzalez et al, 2001). Moreover, the galactic orbits of stars in this region tend to be relatively circular — with low to moderate eccentricity. According to one recent definition of the galactic habitable zone, as much as 10 percent of all stars in the Milky Way may have experienced chemical and environmental conditions suitable for the development of complex Earth-type life over the past eight to four billion years for evolutionary development (press release; and Lineweaver et al, 2004, in pdf). (Further discussion of the different galactic regions and their distinctive stellar populations is available from ChView’s “The Stars of the Milky Way.”)

In recent millenia, the Sun has been passing through a Local Interstellar Cloud (LIC) that is flowing away from the Scorpius-Centaurus Association of young stars dominated by extremely hot and bright O and B spectral types, many of which will end their brief lives violently as supernovae. The LIC is itself surrounded by a larger, lower density cavity in the interstellar medium (ISM) called the Local Bubble, that was probably formed by one or more relatively recent supernova explosions. As shown in a 2002 Astronomy Picture of the Day, located just outside the Local Bubble are: high-density molecular clouds such as the Aquila Rift which surrounds some star forming regions; the Gum Nebula, a region of hot ionized hydrogen gas which includes the Vela Supernova Remnant, which is expanding to create fragmented shells of material like the LIC; and the Orion Shell and Orion Association, which includes the Great Orion Nebula, the Trapezium of hot B- and O-type stars, the three belt stars of Orion, and local blue supergiant star Rigel.

Top Image credit: Yeshe Fenner, STcI, AURA, NASA, ESA

(Source: stellar-indulgence, via atomstargazer)

13 Must See Stargazing Events for 2013

— Listed In Chronological Order 

1) January 21 — Very Close Moon/Jupiter Conjunction

A waxing gibbous moon (78% illuminated) will pass within less than a degree to the south of Jupiter high in the evening sky. Your closed fist held out at arms length covers 10 degrees. These two wont get that close again until 2026.

2) February 2-23 — Best Evening View of Mercury

The planet Mercury will be far enough away from the glare of the Sun to be visible in the Western sky after sunset. It will be at its brightest on the 16th and dim quickly afterwards. On the 8th it will skim by the much dimmer planet Mars by about 0.4 degrees.

3) March 10-24 — Comet PANSTARRS at its best

First discovered in 2011, this comet should be coming back around for about 2 weeks. It will be visible low in the northwest sky after sunset. Here are some sources predicting what the comets may look like in the sky; 1, 2

4) April 25 — Partial Lunar Eclipse

A very minor, partial lunar eclipse (not visible in North America) where only about 2 percent of the moon’s diameter will be inside the dark shadow of the Earth.

5) May 9 — Annular Eclipse of the Sun (“Ring of Fire” Eclipse)

It will be visible in Northern Australia and parts of Papua New Guinea but mostly within the Pacific Ocean. See all the solar eclipse paths for 2001-2020 here.

6) May 24-30 — Dance of the Planets

Mercury, Venus and Jupiter will seemingly dance between each other in the twilight sky just after sunset as they will change their positions from one evening to the next. Venus will be the brightest of all, six times brighter than Jupiter. Look towards the west just above the Sun after it sets to see the three planets grouped together.

7) June 23 — Biggest Full Moon of 2013

It will be the biggest full moon because the moon will be the closest to the Earth (Perigee) at this time (11:32 UT) making it a ‘SuperMoon’. The tides will be affected as well creating exceptionally high and low tides for the next few days. More cool facts about the Moon.

8) August 12 — Perseid Meteor Shower

One of the best and most reliable meteor showers of the year producing ~90 meteors per hour provided the sky is dark. The meteor shower is expected to peak the night of August 11-12, however, you will be able to see a good amount of meteors even in late July. This year (for the peak) the moon won’t be in the way as much as it will set during the evening, leaving the rest of the night dark. Here is a useful dark-sky finder tool to find the best place to watch where you live.

9) October 18 — Penumbral Eclipse of the Moon

Visible mostly in Asia, Europe and Africa, at this time 76% of the moon will be covered by the penumbral shadow of the Earth.

10) November 3 — Hybrid Eclipse of the Sun

A Hybrid Eclipse meaning, along its path, the eclipse will turn from Annular to Total and in this case most of the path will appear to be Total as there will be a slight ring of sunlight visible near the beginning of the track. This one will begin in the Atlantic (near the East Coast of the U.S.) and travel through Africa. See the path here. The greatest eclipse (with 100 seconds of totality) will appear in Liberia, near the West Coast of Africa.

11) Mid-November through December — Comet ISON

The second comet this year, ISON, could potentially be visible in broad daylight as it reaches its closest point to the Sun. It will reach that point on November 28 and it is close enough to the Sun to be categorized as a ‘Sungrazer’. Afterwards it will travel towards Earth (passing by within 40 million miles) a month later. Hopefully it will survive and become brighter than Panstarrs.

12) All of December — Dazzling Venus

The brightest planet of them all will shine a few hours after sundown in the Southwestern sky and for about 1.5 hours approaching New Years Eve. Around December 5th, a crescent moon will pass above the planet and the next night Venus will be at its brightest and wont be again until 2021.

13) December 13-14 — Geminid Meteor Shower

This is another great (if not the best) annual meteor shower. This year put on a show at about 120 meteors per hour and in 2013 it won’t be much different so expect another fantastic show. However, the moon - as it is a few days before full phase - will be in the way for most of the night obscuring some of the fainter meteors. You might have to stay up in the early morning hours (4am) to catch the all the meteors it has to offer. If you missed 2012’s Geminid Meteor Shower, here are some great photo-sets; 1, 2, 3

— Notes
*The gif is of a total solar eclipse, made from this video
* Find a dark sky to watch the meteor showers with this tool
* Estimate your locations meteor shower rate with the Fluxtimator

(via asapscience)

NASA’s Planet-Hunting Kepler Telescope

(Source: atomstargazer, via abcstarstuff)

Carl Sagan | Visionary Scientist

“If we can’t think for ourselves, if we’re unwilling to question authority, then we’re just putty in the hands of those in power. But if the citizens are educated and form their own opinions, then those in power work for us. In every country, we should be teaching our children the scientific method and the reason for a Bill of Rights. With it comes a certain decency, humility and community spirit. In the demon-haunted world that we inhabit by virtue of being human, this may be all that stands between us and the enveloping darkness.”

Cannabis Culture readers born after 1980 missed the heady days of the 1960’s and 70’s, when psychedelic consciousness, direct-action civil disobedience, and the ecology movement ended the Vietnam War, drove a corrupt American president from office, and made every day Earth Day.

The most famous scientist of that tumultuous, idealistic era was Carl Sagan, a boy-wonder astrophysicist and scientific philosopher whose $8 million, 13-part television series, Cosmos, taught half a billion worldwide viewers about the 15 billion-year history of the universe.

Sagan and his third wife, Ann Druyan, co-wrote the best-selling book Cosmos; they also co-wrote the television series.

Sagan’s version of past, present, and future, which he elucidated in award-winning books, movies, essays, and public appearances, was controversial and comprehensive. The vivacious, brilliant scientist gave humans a revolutionary new template for understanding the origins of the universe and the place of the human species therein.

One of his core principals was that humans are “starstuff,” the product of a long and amazing process involving matter, energy, and time.

Sagan said that while he was not an atheist, he failed to find scientific evidence supporting the belief that humans are the most important part of the universe, or that patriarchal gods created them.

Instead of finding meaning in myths and fantasies, Sagan insisted, the measure of our lives lay in the choices we made, contextualized by the humbling admission that we are a “temporary form of life under the creation of a power beyond our comprehension.”

Despite his scientific skepticism of human-centered religions, Sagan was not a materialist or nihilist. Indeed, his ideas were more spiritual, ethical and rigorous than the ideas of many who criticized him for offending their religious-humanist sensibilities.

War, war machinery, prejudice, destruction of nature, superstition, alien abductions, political-consumerist propaganda, religious charlatans, nationalism; Sagan decried these as dangerous, insidious follies.

And as he crusaded for more science education and for application of the scientific method to every aspect of existence, Sagan challenged the human species to be more honest and gentle, and to affirm the value of all life and the universe itself; not because a punishing god commanded it, but because it made the most sense.

Despite unparalleled popularity with the masses, Sagan was attacked by other scientists, who said he was wrong for “popularizing” science, and for telling “regular citizens” to hold scientists accountable for their research and creations.

Creationists lambasted Sagan, saying he preached a “religion called scientism” that did not acknowledge the supremacy of humans or the Father God who allegedly created us. Conservative Republicans, anti-environmentalists, and military-industrial shills called him an “unpatriotic liberal.”

But Sagan’s critics made themselves look bad by attacking the gifted science orator who also possessed impeccable scientific credentials.

Born in Brooklyn, New York, to an American mother and a Russian immigrant father, Sagan decided at age 12 that he wanted to be an astronomer. At age 16, he entered the University of Chicago on a scholarship. He received his first bachelor’s degree when he was 19, and then earned a second bachelor’s degree, a master’s in physics, and a doctorate in astronomy and astrophysics by the time he was 25.

While doing research at the University of California at Berkeley, Sagan discovered the true nature of the atmosphere and surface conditions on Venus. He later discovered important aspects of the Martian atmosphere and the moons of Saturn. He taught at Stanford University and Harvard University, and was a staffer at the Smithsonian Astrophysical Observatory. In 1968, he became director of the Laboratory for Planetary Studies at Cornell University, where he also taught classes. Standing room only crowds always thronged his lectures.

Sagan’s ideas and warnings were prophetic, foreshadowing the development and discoveries of sociobiology, ecopsychology, and evolutionary biology. He predicted or anticipated global climate change, biodiversity loss, genetic engineering, artificial intelligence, space-based weapons, and the Internet.

He was a scientist with the charisma and cache of a rock star; advising the makers of the movie 2001: A Space Odyssey, and appearing with Hollywood celebrities and counterculture icons on behalf of progressive causes. Sagan and Druyan were the guiding lights behind the evocative feature film Contact, starring Jodie Foster. For the National Aeronautics and Space Administration (NASA), Sagan was an adviser on the Mariner, Voyager and Viking unmanned space missions. He also briefed astronauts on journeys to the moon.

His resume, filled with stellar achievements, was 250 pages long.

But fate was cruel. In the early 1990’s, Sagan was diagnosed with a rare bone marrow disease called myelodysplasia. A marrow transplant from his sister temporarily saved his life, but then cancer cells invaded his body.

“I would recommend almost dying to everybody,” he told an interviewer. “You get a much clearer perspective on what’s important and what isn’t; the importance of family and of trying to safeguard a future worthy of our children.”

After a valiant struggle, Sagan died on December 20, 1996, at the age of 62.

While he was alive, marijuana users speculated that Sagan’s provocative, innovative thinking might have resulted from altered consciousness caused by marijuana.

Soon after his death, biographers and journalists made headline news by reporting that Sagan and Ann Druyan were marijuana users and legalization advocates. Much was made of an anonymous essay attributed to Sagan, in which he glowingly detailed how marijuana helped him appreciate art, music, friends, lovers, and his work.

Ann Druyan (pronounced Dree-yan) was Sagan’s last wife, and the mother of two of his five children. She was co-author or collaborator on many of Sagan’s most successful projects, and now directs or manages several production companies which are creating highly lauded scientific and cultural educational materials, space travel vehicles, and media projects. Druyan is especially proud of her role in building the Carl Sagan Discovery Center, the first children’s hospital in the Bronx.

Druyan is also a long-time board member and important fundraiser for the National Organization for the Reform of Marijuana Laws (NORML).

Sagan said of his wife: “In the vastness of space and the immensity of time, it is still my joy to share a planet and an epoch with Annie.”

- - - - - - - - - - - - - - - -

Ann Druyan gave this exclusive interview to Cannabis Culture from her home in New York.

You were married to one of the 20th century’s most famous scientists, and now you are carrying Carl Sagan’s legacy forward. How did you become interested in science?

In 1974, I first met Carl. I was 25 years old. I am 51 now. My knowledge of science came from being with Carl, not from formal academic training. Carl gave me a thrilling tutorial in science and math that lasted the 20 years we were together.

And science for you and Carl has been a way of deciphering the world?

For most of the history of our species we were helpless to understand how nature works. We took every storm, drought, illness and comet personally. We created myths and spirits in an attempt to explain the patterns of nature.

Around the time that humans settled down and began doing large-scale agriculture, some cultures created the notion that storms, floods, lightning, disease, and even our own mortality were forms of punishment meted out by an angry god in the sky.

This misinterpretation of reality was first questioned by the ancient Greek pre-Socratic philosophers, formed by the same culture that invented the idea of democracy. Among them was Hippocrates, one of my heroes. He noted, for example, that people believed epilepsy was a divine curse, because they didn’t understand what really caused it. Hippocrates predicted that the actual cause of epilepsy would one day be understood and as soon as it was, people would stop thinking it was divine. This is the first great footstep on the road to having a scientific understanding of the universe. Incidentally, it was another great pre-Socratic philosopher, Democritus, who said, “Life without getting high is like a road without an inn.”

A lot of people are suspicious of science, because it can so easily be turned to bad purposes.

Carl worked harder than anyone I know of to combat the misuse of science. One of his greatest dreams was of a society where everybody had enough scientific knowledge so they could influence what scientists did with their power. Carl recognized that science should not just be the property of an elite group that speaks some arcane language.

He knew that if we were to have even a little bit of democracy in this society, as many of us as possible should understand the workings, language, values and methods of science and technology so that we can’t be so easily manipulated. He took a lot of abuse from scientists who cherished their elitism.

In researching Carl Sagan for this interview, I found it almost impossible to overstate the breadth of his scientific and academic credentials.

I think Carl was so off-scale because he took so much pleasure in his work. He had a lifelong, unquenchable curiosity. He really wanted to know how the universe was put together. He followed this passion wherever it took him; across scientific disciplines and careers. In his life there was no division between work and pleasure.

His book Dragons of Eden is a masterpiece on the evolution of intelligence and the process of development that led to the three parts of the human brain. Cosmos was the most popular science book in the English language. The Cosmos television series, which we wrote together, was worldwide the most successful 13-part science program in television history. It was a hit among people of all cultures and ages. It is just become available in an updated version on digital video disc ? a 13-hour explanation of how the human species found its part in the great story of the universe.

Carl played a leading role in every single one of NASA’s missions of exploration from the beginning of the space age until his death in December 1996. He was a Pulitzer-prize winning author of more than twenty books, six hundred scientific papers, countless popular articles, television shows and a major motion picture. He probably attracted more people to read, study, teach and do science than any other individual in the history of the world.

He was one of the most conscientious citizens the planet has ever had, among the first to raise the alarm about global warming, a tireless activist against the insanity of the nuclear arms race, and an innovative scientific researcher who was a co-discoverer of the unsuspected possible climactic consequences of nuclear war.

He opened the universe for me as he did for millions worldwide. Not only was he a great scientist who pioneered the search for life and intelligence on other worlds, as well as its origin on this one, he was a leading researcher who discovered much about the atmospheres of other planets. Carl was the first to bring public attention to the dangers of our inadvertent modification of the Earth’s climate and atmosphere.

What accounted for Carl’s ability to get so many people interested in science?

When people would ask him why he went to such lengths to do public science education, why he didn’t just stay in the lab or university classroom, he would always smile and say “when you’re in love you want to tell the world.” To him, science was a series of thrilling revelations that he took to heart. That’s where he spoke from and people were moved. Science had been for most of us a hopelessly impenetrable form of boring torture. The way Carl taught, it became clear and spiritually uplifting.

He combined an awesome respect for reality with a boundless imagination; skepticism and wonder both, never one at the expense of the other. He experienced the soaring high of accepting that we humans are not the center of the universe.

A lot of people have this ego need that makes them want to believe that Earth is the center of the universe and humans are the most important species, the supreme expression of creation. For them, Carl’s view that humans are a part of creation, but not the crown of creation, is an unbearable bummer. Carl felt that seeing us as a part of the fabric of nature is a much bigger and more inspiring perspective. For him it was a liberation. To others it was threatening. The creationists were certainly offended.

Was Carl criticized and persecuted for his scientific-political activities?

During the 1980’s we were arrested three times at the Nevada Nuclear Test Site while protesting US underground nuclear testing. This kind of activism cost him many of the glittering prizes and honors that he might have gotten if he had played along with things he thought were wrong. He turned down three invitations to dine at the Reagan White House. He couldn’t be co-opted. His opposition to the Star Wars swindle drew a lot of fire. I wish the world had a Carl Sagan now to publicly argue against the new Star Wars proposals. He could spot the phony technical arguments of the Department of Defense and bust them publicly in a way that we could all grasp.

I wish there was someone now to challenge the current President’s flagrant disregard for the environment. We were told that when Russia’s President Gorbachev visited the White House, he told Reagan how much he admired Carl’s work. Reagan, who was famous for being grandfatherly and mellow, became uncharacteristically harsh.

Carl took on the military-industrial complex. He campaigned around the world for an end to the production of weapons of mass destruction. To him it was a perversion of science. So yes, it’s true that Carl was frequently denounced by televangelists, astrologers and The Wall Street Journal. Even so, it wasn’t much of a price to pay. He was the happiest person I ever knew.

My impression is that Carl had a spiritual side to him. Is that accurate?

Perhaps his greatest contribution was to teach a new sense of the sacred. It came out of his fidelity to the scientific method and his courage in wanting to see how the universe was really put together, rather than imposing his fantasies, his personal ego needs, his programming, on the universe.

It takes a fearless, unflinching love and deep humility to accept the universe as it is. The most effective way he knew to accomplish that, the most powerful tool at his disposal, was the scientific method, which over time winnows out deception. It can’t give you absolute truth because science is a permanent revolution, always subject to revision, but it can give you successive approximations of reality.

Science reveals a universe far grander, larger and older than our ancestors ever dreamed. Part of Carl’s genius was to re-unite the wonder of spirituality with the rigorous skepticism of science. What resulted was the answer to an ancient yearning that freed us of the need to lie to ourselves.

You co-authored books with him, and acted as a partner in many of his most famous projects. Could you describe your professional collaboration with Carl?

One of our first collaborations was in 1977. I was Creative Director of the Voyager Interstellar Message. This message was encoded in golden phonograph records affixed to NASA’s Voyager I and II spacecrafts. It consists of 27 pieces of music, 118 images, greetings in 59 human and one whale language, and an audio history of Earth.

The Voyager records have traveled farther than any other objects touched by humans on board the fastest moving spacecraft we’ve ever created. They move at 38,000 miles per hour. The discs have a shelf life of 1 billion years. They include Chuck Berry’s Johnny B. Goode, Louis Armstrong performing Melancholy Blues, Blind Willie Johnson’s Dark Was The Night, Bach and Beethoven, a Japanese shakuhachi flute piece, a Bulgarian shepherdess with pipes like Aretha Franklin, a Senegalese instrumental, Peruvian pan pipes, an Indian vocal raga that raises goose bumps and much, much more. Many people have told me that the Voyager collection was their first exposure to what we now call “world music.” I called it Earth’s Greatest Hits.

Designing these golden records felt like we were building a Noah’s ark of world culture. There were six of us on the message team. We’d call people and ask for tapes of their best cricket song or school yard chants, but when we told them it was for an interstellar message there’d be either a long, long pause or a click. We consulted musicians, composers, ethnomusicologists and scientists.

We’ve sent along a needle and record player on both spacecraft. We engraved hieroglyphics explaining how to play the records, along with our address in the Milky Way galaxy to give the finders some clue as to where we are.

If you were to come back to this planet a billion years from now you wouldn’t recognize the surface of our planet because it would have been dramatically changed by large-scale geological processes, but that music would still be playable and revealing of who we were. Hand engraved on each record are the words: “For the makers of music, all worlds all times”.

One of your colleagues told me that you put something very personal into the Voyager messages.

I asked Carl if there was any possibility that if I meditated while I was hooked up to a machine that records brain activity, that someday that data might be deciphered by the putative extraterrestrials. Carl looked at me with a big smile and replied, “A billion years is a long time, Annie. You might as well do it.”

So, on a gorgeous June day, I went to Bellevue Hospital in New York City and was hooked up to a bunch of sophisticated machines while I meditated about the history of life on earth, about the danger we found ourselves in back in 1977 with a planet infested with 50,000 nuclear weapons, and about what I was learning about love. It was the very week that Carl and I had fallen in love with each other.

I was recording this meditation hooked up to a computer the size of a room with scores of technicians recording EKG, EEG, REM, and every neuronal impulse. That hour of meditation was compressed into a minute of sound and included on the Voyager Record. I feel comforted and awed knowing that 500 million or even a thousand million years from now, something of that ecstatic June and our love for each other may survive and be known by another form of intelligent life.

Did you mention cannabis in the Voyager messages?

There is no direct reference to cannabis, but there is a photograph of an elderly man from central Asia who is smoking up. We don’t know exactly what the contents of his very fancy pipe might be, but it may have been cannabis.

We might also speculate about what was coursing through the bloodstreams of some of the scientists, engineers, artists, composers and musicians who made the Voyager Message possible. Louis Armstrong, who loved marijuana, is featured on the record.

Marijuana is something both you and Carl cared deeply about?

Yes, and I know that sometime in the not too distant future, we will look back on the fact that we persecuted people for marijuana use the way we looked at the idea of putting homosexuals in prison, or persecuting ethnic minorities. It’s a barbaric policy that people who should know better are somehow content to abide.

How can we tolerate this war? What does it say about us as a people? America has a population of 280 million, a tiny fraction of the world’s population. Yet we have 25% of all the people imprisoned on the planet. What does it say about “the land of the free?” And a significant percentage of people in prison are there for nonviolent drug offenses?

Recently, US courts sentenced a quadriplegic man, and an armless, legless woman, to jail for small quantities of marijuana. As if people in those circumstances were somehow too free, and needed further restraints on their freedom.

You’ve gone public with your call for marijuana law reform, just as your husband did several years before he died.

About ten years ago, a caller asked Carl on the Larry King radio show if he was for legalizing marijuana. He didn’t hesitate to say yes. My recollection is that Larry followed up by asking Carl if he had ever smoked marijuana, and he again said yes. We thought there would be some fallout, but there was none. We didn’t hear anybody say that Carl Sagan was a bad person because he used marijuana, and indeed marijuana was a wholly positive part of his life.

In our culture you generally only learn about a famous person’s marijuana use in the context of their disintegration, usually because of an arrest or enrollment in some treatment program. I think it’s worthwhile to take note of a life so fully realized as Carl’s was, a life in which marijuana was significant and positive, rather than a problem.

You’re very open about your marijuana advocacy, even though other people in your position might have kept it hidden. How has this affected your life?

When it became publicly known that Carl and I used marijuana, I expected some harassment, but we didn’t get any. What was surprising is the people who would come up to me and say “thanks” for being up front about marijuana. They were not hippies, they were regular working people who had to worry about urine tests, whose jobs required they wear a uniform. They had to hide their marijuana use from society and even their own children.

I’m not talking about changing the image of marijuana users from hippies to yuppies. I want to show that all kinds of people - hard-working blue-collar people, scholars, people from all walks of life, the backbone of the country - they smoke marijuana!

It’s safe to say that Carl’s vital and energetic approach to life clashed with drug war propaganda that says “marijuana users are losers.”

Absolutely. In my experience, responsible marijuana use is compatible with a healthy, fulfilled life; one of honesty, ethics and accomplishment. Carl’s marijuana use never impinged on any aspect of his responsibilities, and I think it’s illustrative to recall that he taught at Cornell, ran the Laboratory for Planetary Studies, mentored graduate students who have become among the most influential leaders in their scientific fields, edited the highly regarded scientific journal Icarus, co-founded The Planetary Society, edited its beautiful and informative bulletin for 16 years, wrote and edited countless books, one of which won the Pulitzer Prize, co-wrote a landmark award-winning television series, wrote countless articles and speeches on wide-ranging topics, participating in every NASA mission, volunteer teaching at public schools and the list goes on.

Carl’s life itself was a challenge to drug war lies. He was as completely developed a human being as I have ever met, and he smoked marijuana. The superlative nature of his life is significant evidence that counters those who say marijuana prevents people from maximizing their potential. If there’s an “amotivational syndrome” associated with pot use, we certainly don’t see any evidence of that in Carl’s life. And I believe there are a huge number of responsible citizens who use pot appropriately and contribute enormously to our society. The question is, why are they so passive in the face of unreasoning persecution?

That passivity has been one of your main concerns as a member of the board of the National Organization for the Reform of Marijuana Laws.

I’ve been a NORML board member for nearly a decade. Those of us involved with NORML have often wondered why people don’t contribute more, why they don’t help the cause more. Some of those who are sympathetic to our cause are afraid to affiliate with us. Marijuana reform advocates are a victim of a kind of McCarthyized propaganda campaign that includes professional, economic and legal penalties for people who try to change the laws. Some people are afraid to write checks to NORML or even to be on our mailing list.

How can individuals fight against the drug war?

I’d like to see us get off the defensive and be more assertive. It’s mostly poor people, or people with very bad luck, who get caught up by drug laws. A lot of people in the suburbs, with respectable jobs, are somewhat insulated from the injustices of the drug war. I’d like to see them stand up and register their opposition.

I am convinced there are more marijuana smokers than fundamentalist Christians, for example, but the fundamentalists are far better organized, more dedicated, more willing to spend time and money for what they believe in. (Of course they are not persecuted for their beliefs.)

They are a potent cultural and political force, while marijuana smokers are comparatively passive and too easily intimidated into silence. The secrecy and dishonesty is pernicious, it corrupts and corrodes human relationships and the marijuana experience itself.

What can NORML do to help the cause?

I wish more people knew how dedicated the people at NORML are. Keith Stroup and Allen St Pierre have been working at this for a long time. They could both be doing something else that would be far easier and personally much more lucrative.

Right now, it feels as if their hard work is beginning to pay off. Our work with Governor Gary Johnson in New Mexico seems to be getting some results. We are forging new relationships, working with groups across the political spectrum. NORML is trying to cultivate a better relationship with the grassroots activists who don’t have much money to work with. But we are also seeking to change the public’s perception of the stereotypical marijuana user. We don’t want people to only be known for marijuana use when they are on their way to jail. And there’s nothing bad about the pot-smoking hippie image, but we also need to show that all kinds of people use marijuana.

What has cannabis meant to you? What did it mean to your husband?

It’s a sacrament and we treated it as such, with respect. Our species has an ancient history of experience with marijuana. Our ancestors knew how to integrate marijuana use into the life of their community; to find a balance. That’s what we tried to do. Not that we had any rigid rules for use. There was plenty of spontaneity; but no abuse. I have used it since I was a teenager in the ‘60’s, and it has never interfered with my health or productivity.

For me it has been a gateway drug, but not a gateway to anything destructive, but to a more glorious understanding of my part of the fabric of nature and to an ever-deeper relationship with my family. Carl and I both found it put us in a state of mind that made us more receptive to new ideas, more sensitive to other people’s feelings, more able to focus on the great natural pleasures of life.

Throughout our lives, there were long periods of time when we didn’t have any marijuana. We didn’t jones for it. I know there are people who have problems becoming dependent on it. We never experienced any such problems.

In the two years of suffering leading up to Carl’s death, he had radiation and chemotherapy during the course of three torturous bone marrow transplants. His physicians prescribed Marinol. He tried it several times and he hated it. He found it stupefying. He said that Marinol’s effects were everything you don’t want ? it deadens you, it makes you sleepy, and you can’t function. He used medical marijuana during that period, and it helped him control nausea, have an appetite, and it lifted his spirits.

Medical marijuana definitely helped Carl, who wrote two books during this period, and we collaborated on the movie Contact. His doctors told me he was the most forward looking patient they’d ever seen, never once complaining, always trying to get back to work. They told me they had precious few patients who could read books during bone marrow transplants, much less write them.

Have you had any cannabis moments that you care to share?

Carl and I shared a love for Bob Marley’s music. I was thrilled to be invited to Bob Marley’s birthday celebration last year at his house on Hope Road in Kingston, Jamaica. I got the invitation because I was asked on CNN if there was anything I wish I had included on the Voyager records, and I said, “Yes, Bob Marley’s song No Woman, No Cry.” I then went into a riff on what the song meant to me. Somebody from the Bob Marley Foundation heard what I said on CNN, and invited me to participate in the Jamaican celebration.

But it turned out to be an unsettling event. Rita Marley was magnificent; it was such an honor to meet her, but the actual celebration felt somewhat co-opted by people whom I think Bob Marley would not have felt at home with. For example, we were only served alcohol, and it was this glittering party full of glamorously dressed people, with almost all the rastas locked outside the gate. The Marley image had been taken over by the chamber of commerce, turned into an icon of tourism, mutated into a kind of universal theme park version of Bob Marley.

I told Rita I felt it was somewhat depressing to see how Bob’s image had been sanitized. The Bob Marley these people were talking about would not have been a threat to anybody. I wanted to hear about the “get up-stand up” Bob Marley.

Rita said, “You must get up there and speak.” At first I refused, because I was an outsider and there as a guest, but she said, “No, no, no ? you have to get up and say this to everyone.”

So she went to the microphone and introduced me, saying, “This lady has something to say about what’s missing here.” About half the people in the audience welcomed what I said. I could see it in their faces. They were saying, “Yes, yes!” But a third of the audience was giving me these really hard looks, like they wanted me to shut up about the real Bob Marley: a freedom fighter, a revolutionary, and a man of ganja.

I admire your candor, and I appreciate the time you’ve taken from your exciting schedule. We’ve talked a lot about the past, and about your husband, but please tell us about your current endeavors. I understand that some of them are “out of this world.”

I founded a company called Cosmos Studios that supports bold, original scientific research, clean technology and educating the widest possible audience about the romance of scientific discovery. We most want to communicate the spiritual power of science’s central revelation; our oneness with the universe.

Our first project was updating and re-releasing the Cosmos series in VHS and DVD formats. We’ve also released a compact disc of the music from the Cosmos series. We have four new television projects in production and a half a dozen more in development. These projects strive to embody the values and insights that we learned from Carl.

Our most ambitious undertaking so far will be the launch of Cosmos I, the first solar sail in history. It’s been known for many years that you could use big reflective sails to get up to speeds that would make interstellar travel feasible. A solar sail is a spacecraft powered by light. If our current understanding of physics is correct, the only way we can get to the stars is on a vehicle powered by sunlight and, once you get too far from the sun, by lasers. Theoretically, solar sails can travel ten times faster than NASA’s Voyagers, making it possible to travel across the incomprehensibly vast distance between us and the nearest star.

This spring, we’ll be launching a sub-orbital test flight that will be lifted on an ICBM launched from a Russian sub in the Berents Sea. The test launch will determine whether two of the Mylar sails, which are like the petals of a huge flower some seventy feet across, will open properly. We plan to launch the actual craft in the fall. It should be visible to the naked eye. The budget for the entire mission is $4 million.

We are proud to be launching a symbol of the potential of alternative energy sources, working with former adversaries, turning their broadest sword into a means of peaceful scientific exploration, and pioneering space travel.

I’d like to ride on a solar sail and smoke a joint in space! It seems that freedom, the freedom to use a god-given plant, the freedom to define one’s own sense of what is sacred, the freedom to do ethical science, is something that meant a lot to you and Carl.

One of the great promises of America, one which we have yet to fully live up to, is the promise of freedom, the promise that we can explore our creativity and push the limits of human potential. America’s founders invented a constitution that granted new freedoms, but now we lead the world in oppressing people’s freedom to alter consciousness.

For us, it has been a religious issue. Religious freedom shouldn’t be limited to established religions. Marijuana can certainly be a means to a qualitative religious experience. It helps you appreciate the complexity and beauty of the universe. If we really believed in religious freedom we’d say that there are millions of people who derive something spiritual and meaningful from this marijuana. They should have the right to enjoy what they consider sacred. Smoking marijuana can be an aperture to a deep appreciation of what is holy, beautiful and sacred. We should encourage people to do this wisely, instead of persecuting them.

I’ve spoken with you several times, and I’ve been impressed by your dedication to Carl Sagan’s legacy. But I also sense that you are still grieving for him, and may never get over the loss.

I miss him but I accept the fact of his death. I’m mostly left with an overwhelming sense of my good fortune to have him in my heart for the rest of my life. I try to stay alert to the great beauty of being alive.

But for you, it was like losing a precious dream.

Carl and I were like two euphoric, ecstatic sea mammals moving through oceans at great speeds without having to worry about impediments or dangers, without having to use turn signals to alert the other to a change in direction. We appreciated each other completely and missed few chances to tell each other how honored and happy we felt to be on the same tiny planet in this unimaginably vast universe during the same epoch in the whole sweep of cosmic evolution. It seemed like a miracle to us.

Carl apparently didn’t believe that Carl Sagan would live on, in some discreet but non-physical form, after his death. Are there any ways in which you feel, however, that Carl might still be said to be alive?

I do not believe that Carl is still alive in any supernatural way. My understanding of science and reality tells me that most likely, when we die, we end, that’s it. We’re gone.

Yet, there is a way in which he is still alive. When you spend 20 years with somebody day and night, you have their voice in your head ? not in some supernatural way or like a mental illness, where you hear voices ? but your loved one’s voice and their way of thinking, through years of experience becomes imprinted in your brain. Carl’s magnificent laugh is in my head and so he is with me in that way.

And we created two wonderful children who are distinct individuals, but who already manifest some of Carl’s most wonderful qualities. He lives in them and all the countless people who tell me he changed their lives for the better.

If the universe is indeed 12.5 billion years old and the most you as an individual can hope for is 100 years, and there’s more billions of years to come, the only victory is to live fully and completely, to be totally alive every moment you’re here. Do whatever you can to make this planet less brutal and squalid. Ask questions that make a difference, work for justice. Make your short burst of life count.

The reason I was able to survive the grief of Carl’s death is that the authenticity of what we experienced together was so pure. I learned that if you really love someone you should be very nice to them, because what’s really going to haunt you after they die is the times you were grumpy to them, or didn’t take an opportunity to show your love.

If you feel like what was between you was totally cool, that you did everything you could with the time you had, that you lived fully and ethically, then your sadness is tempered by thankfulness.

via Cannabis Culture

Stay Curious! | Watch the Carl Sagan Tribute Series, amp; Carl Sagan’s (Remastered) Spaceship Of The Imagination, Reid Gower’s ‘Sagan Series’, Callum C. J. Sutherland’s Carl Sagan Archives Enjoy. Ad Astra Per Aspera.

Cosmos Will Get a Sequel Hosted by Neil deGrasse Tyson

More than three decades after it aired, Carl Sagan’s groundbreaking, brilliant 13-part TV series Cosmos:A Personal Voyage will finally get a sequel.

Cosmos, which originally ran in 1980 and was rerun many times over the following decade, is widely regarded as one of the first, and best, TV shows to make science accessible to everyone. You can watch the show now on Hulu, but despite its brilliance it is still a show from more than 30 years ago, and you can tell — the special effects are primitive by today’s standards, but more importantly some of the content has been superseded by discoveries in the intervening years.

So, it’s high time someone made a sequel to it, and now someone is! In partnership with Sagan’s colleagues Ann Druyan (who is also his widow) and Steven Soter, Seth MacFarlane — yes, that Seth MacFarlane — is going to produce a new 13-part series to serve as a sequel and modern update to Sagan’s masterpiece.

Taking over the hosting duties will be none other than well-known astrophysicist Neil deGrasse Tyson, who has served as host of NOVA ScienceNOW on PBS for the past five years, so he has plenty of experience making science accessible to the general public. It would be difficult to think of anyone who would be better able to succeed the late, great Carl Sagan.

The folks working on it will take their time and do it right — it’s not scheduled to air until sometime in 2013.

The producers of the show say the new series will tell “the story of how human beings began to comprehend the laws of nature and find our place in space and time.” They go on to boast: “It will take viewers to other worlds and travel across the universe for a vision of the cosmos on the grandest scale. The most profound scientific concepts will be presented with stunning clarity, uniting skepticism and wonder, and weaving rigorous science with the emotional and spiritual into a transcendent experience.”

That’s the good news. The bad — or at least, potentially bad — news is that, because of MacFarlane’s involvement, the series will air in prime time, and on Fox.

Now, in one way I’m all for showing it in prime time on a major network, because it’ll be that much more likely that people who routinely ignore the Discovery Channel, the Science Channel and, yes, PBS will actually see it.

I’m less thrilled, though, that it will have to compete with other, more mainstream prime-time shows — and it’ll be on Fox, which doesn’t have the greatest track record for giving shows a chance to pull their ratings up once they go down.

Now, maybe the fact that MacFarlane is involved — and Joss Whedon isn’t — will help. I certainly hope so.

You can find out more about the plans for the series.

(Source: spaceplasma, via applepiesfromscratch)

Last week’s crafts means this week’s fun! 

Tissue Paper Corsages for Mother’s Day: http://www.pbs.org/parents/crafts-for-kids/tissue-paper-corsage/

Sponge Balls for Outdoor Fun: http://www.pbs.org/parents/crafts-for-kids/sponge-balls-video/

Beautiful Solar System Art is Out of This World: http://www.pbs.org/parents/crafts-for-kids/solar-system-art/

Submit your crafts to our blog, Crafts for Kids!

(Source: pbsparents, via pbsparents)

Think Outside the Box to Find Extraterrestrial Life

Our Milky Way galaxy, and the billions of others beyond, is chock-a-block with extra-solar planets, scientists have learned in recent decades. But whether any of them can support life is a far more complex and contentious issue.

Many researchers hold that potentially “habitable” planets have to be rocky and within a limited zone in relation to their central sun—conditions that allow for the continuing presence of liquid water on their surfaces. (See: “Most Earthlike Planets Found Yet: A ‘Breakthrough.’”)

But in a provocative review article published this week in the journal Science, theoretical physicist Sara Seager of the Massachusetts Institute of Technology lays out a case for habitability being potentially more common than generally predicted.

As a pioneer in the study of exoplanet atmospheres, she paints a different picture of what kinds of planets might support life.

“Our basic premise is that to be habitable, a planet has to have liquid water,” Seager said in an interview. “In addition, planets with thin atmospheres are mostly heated by their stars.”

“But what primarily controls surface temperature is the greenhouse effect, what types of gases are in the atmosphere, and how massive a planet’s atmosphere is. That’s what we really have to understand.”

Not Your Usual Planet
With that in mind, Seager describes how large planets ten times farther from their stars than Earth is from the sun could also have liquid water and potentially life if, for instance, they had enough hydrogen gas in their atmospheres.

Hydrogen gas, she said, has a much more powerful greenhouse effect than what’s in our atmosphere. So it could potentially keep a planet’s surface warm with far less radiation from its star.

Relatively dry planets that are close to their suns could also be habitable, Seager said. They need to have less water to create suitable temperatures at their surface because atmospheric moisture is the most effective greenhouse gas of all. (See: “Smallest Exoplanets Found—Each Tinier Than Earth.”)

She described Venus as an example of the dynamic run amok: The close-in planet once had a lot of water, but the presence of so much moisture set off a runaway greenhouse effect that ultimately made the planet unlivable. A drier early Venus, she said, might have evolved into a quite habitable planet.

Planets that aren’t even orbiting stars—the many free-floating planets now known to exist—could support life, she said. They would need heat generated by radioactive or other processes at their cores, as well as the necessary atmospheric gases to keep the warmth in the atmosphere. (See: “‘Orphan Planet’ Spotted, Orbits No Star.”)

“If there is one important lesson from exoplanets,” Seager writes in her Science review, “it is that anything is possible within the laws of physics and chemistry.”

Astronomers have been extraordinarily successful in finding exoplanets in recent years, and have been finding many within what are considered to be classic habitable zones.

Signs of Life
The next step for the researchers is to learn how to identify elements and compounds in the atmospheres that are considered “biosignature gases,” or signs of possible life. This is Seager’s specialty.

On Earth, for instance, the presence of large amounts of atmospheric oxygen is a sure sign of life because it would quickly bond with other elements and disappear if not constantly replenished.

In exoplanet atmospheres other compounds, like ozone and methane, especially in conjunction with oxygen, would be considered signs of possible extraterrestrial life.

James Kasting, an exoplanet expert from Pennsylvania State University, said that Seager’s views on the potential diversity of habitable exoplanets are similar to those held by others in the community. But her emphasis on these planets as targets for future exploration is something of a challenge.

That’s not because of the science involved, but because of long-planned and long-frustrated efforts to have NASA launch an orbiting telescope that could actually image and analyze exoplanet atmospheres.

Eye in the Sky
A past effort to get such an instrument off the ground—called the Terrestrial Planet Finder (TPF)—is extremely unlikely to be funded anytime soon because of its $5 billion-plus price tag.

“The telescope we hope someday will be built has to be designed to look for particular kinds of planets,” Kasting said. “Many of us believe a TPF telescope that looks at planets in more conservatively defined habitable zones is more likely to be successful than those that look for these hydrogen exoplanets or others outside of our best understood areas.”

While a TPF mission is well off in the future, NASA recently approved development of another exoplanet-finding satellite called the Transiting Exoplanet Survey Satellite (TESS).

Scheduled to launch in 2017, TESS will look for exoplanets around 500,000 of the smaller, cooler class M stars that are relatively close to our solar system. In contrast, the Kepler Space Telescope searches for exoplanets in a distant region containing 150,000 stars hundreds of light-years away.

TESS will not be capable of providing significant information about exoplanet atmospheres on its own, but it may be able to do so in conjunction with the James Webb Space Telescope “if we’re lucky,” Seager said. The James Webb Space Telescope is scheduled to go up in 2018.

Seager concludes her journal article by writing that despite obstacles, “the field of exoplanet characterization is on track to understand habitability and to find habitable worlds.”

That doesn’t mean extraterrestrial life necessarily exists, or that any possible future detection will come with 100 percent certainty, she said. But at least we’re getting ever better at looking.

Stay Curious. Watch: Somewhere, Something Incredible Is Waiting To Be Known (Carl Sagan Tribute Series)

The Astronomer’s League by Mike Gottschalk

Star systems great and small

Upper image: Comparison of blue hypergiant R66 with its disk of dusty material, and our Solar system.

Lower image: The sun-like star 55 Cancri A and 4 members of its planetary system, compared with the brown dwarf Cha 110913-773444 with a hypothetical planetary system (this brown dwarf is known to have a protoplanetary disk).

(Source: invaderxan)

Chasing the Edge of the Solar System | Voyager 1 and 2

For most of it’s lifetime, Voyager 1 has been traveling through uncharted territory. Initially launched to study the outer planets, Voyager 1 has soldiered on past Jupiter and Saturn and on to the outer edges of the solar system. It’s currently the farthest human-made object from Earth, but when will it be the first spacecraft to travel between the stars? Well, we won’t know until we answer two more fundamental questions: Where does our solar system end and the rest of the space between the stars begin? And if you were at the “edge” of our solar system, how would you know you had left?

Recent scientific discussions on the Voyager spacecraft missions have captivated many people. And as the scientific debate swirled around the internet in near-real time, it became clear that these questions are not easy to answer.

As the Principal Investigator for NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft, I lead a team that is also studying this last frontier of our solar system. Data from IBEX complements the Voyager spacecraft—both missions are working together to find the very farthest reaches of the solar system. Unlike the Voyager spacecraft, which are careening out into interstellar space, IBEX orbits the Earth, collecting particles that have traveled in from the solar system’s boundary region and beyond. From those particles, we can determine many things, including what the boundary is like and what, exactly, is happening out there.

More Than Planets
Most everyone knows our solar system is composed of small solid objects orbiting the Sun—planets, comets, and asteroids. But there’s more to it than that. Our Sun continuously emits a “wind” of material outward in all directions, typically at speeds of about a million miles per hour (1.6 million kilometers per hour). The solar wind is composed mostly of charged particles, such as electrons and protons. It also carries the Sun’s magnetic field.

As the solar wind streams away from the Sun, it races out past all the planets, past Pluto, and toward the space between the stars more than 10 billion miles away. We tend to think of that space as empty, but it’s not. Rather, it contains cold hydrogen gas, dust, ionized gas, and traces of other material. Called the interstellar medium, it’s a very thin mix that comes from exploded stars and the stellar wind of other stars.

When the magnetic fields of the solar wind hit the magnetic fields of the interstellar medium, they do not intermix. The expanding solar wind pushes against the interstellar medium, clearing out a cavity in interstellar space known as the heliosphere. The boundary of that bubble is where the solar wind’s strength exactly matches the pressure of the interstellar medium. We call it the heliopause, and it’s often considered to be the very outer edge of our solar system.

The Heliopause
A few things about the heliopause: It isn’t an impermeable wall. Instead, it’s more like the edge of a forest clearing—the boundary is well defined, but easily negotiated. It’s also shaped more like a drop of water than a uniform sphere. That’s because our entire heliosphere, which contains our Sun, the planets, and everything else in our solar system, is moving through the interstellar medium at about 50,000 miles per hour (80,000 kilometers per hour). That motion creates a wake in the interstellar medium, much like a boat moving through water. As the solar system travels through the interstellar medium the heliopause is closest at the “front,” or the foremost point in the direction in which our solar system is traveling. At that point, the heliopause is still over 10 billion miles, or 16 billion kilometers, from the Sun.

At least, that’s our best guess. We don’t know exactly where the boundary is or what it’s like. That’s what the IBEX and Voyager missions are trying to find out. IBEX lets us peer into the boundaries of our solar system to get a better idea of what it’s like and what’s happening there. However, because IBEX orbits the Earth, we cannot use it to mark where the boundary is located. That’s where Voyager 1 and 2 come in. Currently, they are directly sampling the boundary region. Several of the instruments on Voyager 1 and 2 are no longer working, including the cameras used to snap the stunning fly-by photos of Jupiter, Saturn, Uranus, and Neptune, but others that detect charged particles and magnetic fields are still gathering data.

Both Voyagers are traveling in roughly the same direction as our solar system through the interstellar medium. We expect Voyager 1, the quicker and farther out of the two, to reach the heliopause first. Currently, it’s just over 11 billion miles, or 18 billion kilometers, from the Sun. This is so distant that radio signals from Voyager 1, which are traveling at the speed of light, take 17 hours to reach Earth.

Three Criteria
Before we can declare that Voyager 1 has crossed the heliopause, we are waiting to observe three main changes:

A decrease in highly energetic charged particles from inside our heliosphere,

An increase in highly energetic charged particles from outside our heliosphere,

And a change in the strength and direction of the magnetic field, matching that outside the heliosphere.

Voyager 1 observed the first two in late 2012, and IBEX has provided what are likely the best observations of the third. By using IBEX to look at particles that have traveled in from outside the heliosphere, we have an idea of the direction of the magnetic field beyond the solar system, and it’s very different from the Sun’s, which is carried out by the solar wind. So far Voyager 1 hasn’t observed this change direction of the magnetic field. That’s why we don’t think that Voyager 1 has crossed the heliopause—yet.

Now, Voyager 1 has clearly passed into a new region of space, one that we have not detected before. Every new bit of data coming from the venerable spacecraft is teaching us more about this uncharted territory. All of this information is new, and we are learning more every day.

So, do we know when Voyager 1 will cross the heliopause? We really have no idea. And that’s part of the fun. But learning about the edge of space is more than just an esoteric pursuit. Our heliosphere is a protective cocoon, a crucial layer of shielding against dangerous charged particles, known as galactic cosmic rays, that are harmful to living things. Understanding it will help us understand how the heliosphere has protected our solar system, enabling life to flourish on this planet we call home. And someday, that knowledge will help us prepare for our first voyage beyond the protective cocoon of the solar system, when we step across the threshold and venture into deep space.

image 1: The identical Voyager 1 and Voyager 2 are currently probing the farthest reaches of the solar system.

image 2: As solar wind pushes out against the interestellar medium, it creates a bubble known as the heliosphere; the boundary between the two is known as the heliopause. The termination shock is where the solar wind slows as it presses against more of the interstellar medium, which also raises the plasma’s temperature. The bow wave is where the interstellar medium material piles up in front of our heliosphere, similar to water in front of a moving boat.

image 3: The IBEX satellite orbits the Earth, capturing particles that have traveled into the solar system from beyond the heliosphere.

via NOVANext, PBS.org

Stay Curious! Watch: And Still They Move: Ann Druyan on Carl, Love, and Voyager

(Source: space-pics)

(Source: neonnomad, via likeaphysicist)

*Psst, Hey. Neil.

*Gaileo spoke of Jupiter, it’s moons and Saturn and it’s accompanying rings in the 1600’s.

*What’s going on here, I just found the same thing being stated in Wikipedia. Someone explain this to me.

Chapter 1: Pluto in Culture, Page 8 from Neil deGrasse Tyson’s “The Pluto Files: The Rise and Fall of America’s Favorite Planet”

Edit: Even though Jupiter and Saturn could be seen with the naked eye, they weren’t immediately recognized as planets, they were referred to as ‘stars’. Galileo defended this misunderstanding immediately during his advocation of the Copernican System and kept us aware of several distinctions like this. He’s made me so much more aware of his presence during his life and ultimately, our natural history. Also, Galileo invented the telescope in the 1600’s by improving the magnification of the nautical tool, the spyglass. He wrote a whole book on Sunspots. And comets. I simply think Neil (and all of us should be more clear about this. I don’t believe I’ve ever even found this subject brought up, so I’d appreciate any contribution to this personal thought :)

Search Is On for ‘Eyeball Earth’ Alien Planets

Alien worlds resembling giant eyeballs might exist around red dwarf stars, and researchers are now proposing experiments to simulate these distant planets and see how capable they are of supporting life.

Red dwarfs are small, faint stars about one-fifth as massive as the sun and up to 50 times dimmer. They are the most common stars in the galaxy and are thought to make up to 70 percent of the stars in the universe — vast numbers that potentially make them valuable places to look for extraterrestrial life.

Indeed, the latest results from NASA’s Kepler space observatory reveal that at least half of these stars host rocky planets that are half to four times the mass of Earth. [Gallery: A World of Kepler Planets]

Tidally locked ‘eyeball Earths’
When looking for alien life as we know it, scientists typically focus on worlds that have water, since there is life virtually everywhere there is water on Earth. As such, they concentrate on the habitable zone of a star — the area surrounding a star where it is neither too hot nor too cold for liquid water to exist on a planet’s surface.

Since red dwarfs are relatively cool, their habitable zones are often closer than the distance at which Mercury orbits the sun. This makes it relatively easy for astronomers to spot worlds in a red dwarf’s habitable zone — the exoplanets’ orbits are small, meaning they complete them quickly and often, and researchers can in principle readily detect the way these worlds regularly dim the light of these stars.

When a planet orbits a star very closely, the gravitational pull of the star can force the world to become tidally locked with it.

“This means that they always show the same side to their star just as our moon does to the Earth, which means they have one permanent day and one permanent night side,” study lead author Daniel Angerhausen, an astronomer and astrobiologist at Rensselaer Polytechnic Institute, Troy, N.Y., told Astrobiology Magazine.

This scenario of permanent day and permanent light could lead to a striking kind of world — one resembling an eyeball. Its night side would be covered in an icy, frozen shell, while its day side would host a giant ocean of liquid water constantly basking in the warmth of its star. [9 Exoplanets That Could Host Alien Life]

“For me, the eyeballs are just one example of the plethora of crazy things we are finding out there in space,” Angerhausen said. “In the field of exoplanets we find hot Jupiters, highly eccentric planets that light up like comets when they come close in to their host star, or evaporating Mercurys — all of them planets that we don’t have in our solar system and that astronomers did not even dream about 10 or 20 years ago.”

The idea of an eyeball Earth, as such a world is called, was spurred by the detection of an exoplanet called Gliese 581g about 20 light-years away, which may be the first known potentially habitable alien world (although scientists continue to debate whether the planet really exists). Planetary geophysicist Raymond Pierrehumbert of the University of Chicago suggested that if Gliese 581g is real, it could be an eyeball Earth.

“We already have telescopes that detect planets that might be eyeballs,” Angerhausen said.

Given the profound differences between the day and night sides of eyeball Earths, “they are potentially the easiest habitable terrestrial planets to detect and distinguish,” Angerhausen said. However, little is known about precisely how easy they are to detect and how habitable they really are.

“Our proposal will find out how common and stable these eyeballs are,” Angerhausen said.

Modeling eyeball Earths
To learn more about what eyeball Earths might be like, Angerhausen and his colleagues are proposing a project they hope to carry out in Brazil dubbed HABEBEE, short for “Exploring the Habitability of Eyeball-Exo-Earths.” The plan is to for the first time see what a stable eyeball Earth needs to support life.

The scientists first aim to construct a variety of eyeball Earth models that vary in mass, distance from their stars, how much radiation they receive, magnetic field strength and their ice composition and density. By providing general and extreme cases of stable and transient eyeball Earths, they can help predict how well existing and future telescope surveys can detect and characterize them.

An eyeball planet is one of several possible scenarios for planets in a red dwarf’s habitable zone.

“A little bit closer to the star — that is, hotter — they would completely thaw and become water worlds; a little bit further out in the habitable zone — that is, colder — they would become total iceballs just like [Jupiter’s moon] Europa, but with a potential for life under the ice crust,” Angerhausen said. “These planets — water, eyeball or snowball — will most probably be the first habitable planets we will find and be able to characterize remotely. Thats why it is so important to study them now.”

The ocean of an eyeball Earth will likely span a range of temperatures. “It’s probably pretty hot in the center of the eye and then gradually gets colder towards the edge of the ice crust,” Angerhausen said. Still, much remains uncertain — for instance, if the ocean transports heat well, the planet might warm enough all over to turn into a water world without ice, he suggested.

The researchers also plan an expedition to the Antarctic Peninsula to gather specimens of microbes at transition zones between ice and water that might be analogous to oceans on eyeball Earths. The aim is to see what metabolism of life on the alien worlds might be like.

The researchers finally aim to see how well life can survive on eyeball Earths using an existing planetary simulation chamber originally designed to imitate Mars at the Brazilian Astrobiology Laboratory. Antarctic microbe samples can be tested in atmospheric, radiation and other conditions that simulate a number of possible eyeball Earth scenarios. The researchers can test the survival and genetic activity of the microbes to see how well they behave.

“I like the idea of having a few cubic meters of space that mimic another world in a chamber,” Angerhausen said. “It’s like having a probe from a world light years away in a jar.”

Detecting life?
Over the course of their lifetimes, red dwarfs can go from barely to highly active when it comes to dangerous bursts and flares, causing ultraviolet radiation to jump by 100 to 10,000 times normal levels and potentially sterilizing the surface of a nearby planet or even helping to strip off its atmosphere.

To see what harm such radiation might wreak on the habitability of eyeball Earths, the researchers plan to monitor the radiation levels of known red dwarfs over time and investigate previously gathered red dwarf radiation data, knowledge that can help them simulate red dwarfs better.

They also plan on understanding the effects of streams of energetic particles from red dwarfs on the surfaces and atmospheres of eyeball Earths by using the Brazilian National Synchrotron Light Source at Campinas to blast ice with radiation.

“It is not obvious that these planets could be stable for long periods, which we believe is necessary for the origin, maintenance and evolution of life,” said astrobiologist Douglas Galante at the Brazilian Synchrotron Light Source, who organized the Sao Paulo Advanced School of Astrobiology where Angerhausen and his colleagues initiated the HABEBEE proposal.

“Many more studies have to be done, theoretical, experimental and observational, so that we better understand the habitability of these planets,” Galante added.

Upcoming and current telescopes such as NASA’s James Webb Space Telescope might be able to see if planets have eyeball structures. When telescopes improve further, astronomers could look for molecular signs of life on eyeball Earths, researchers said.

“To finally detect life or what we call ‘biomarkers,’ we probably have to wait for next-generation telescopes, such as the 30-meter-class ground-based telescopes that are currently getting built and future space-based platforms such as the Terrestrial Planet Finder,” Angerhausen said. “However, history shows that astronomers are quite creative using current available instruments and telescopes, so maybe one of my colleagues may come up with a new exciting observation strategy that will make it even possible earlier.”

The scientists detailed their findings in the March issue of the journal Astrobiology.

This story was provided by Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program.

I look up — many people feel small because they’re small and the Universe is big — but I feel big, because my atoms came from those stars. There’s a level of connectivity.

That’s really what you want in life, you want to feel connected, you want to feel relevant, you want to feel like a participant in the goings on of activities and events around you.

That’s precisely what we are, just by being alive…

- Dr. Neil DeGrasse Tyson [ x ]

(Source: quantumeagle, via thedemon-hauntedworld)