americawakiewakie:

Science 

(Source: america-wakiewakie, via robcayman)

Formations of Planets in a Protoplanetary Disc

thenewenlightenmentage:

When Stellar Metallicity Sparks Planet Formation

In new research, scientists have attempted to determine the precise conditions necessary for planets to form in a star system. Jarrett Johnson and Hui Li of Los Alamos National Laboratory assert that observations increasingly suggest that planet formation takes place in star systems with higher metallicities.

Astronomers use the term “metallicity” in reference to elements heavier than hydrogen and helium, such as oxygen, silicon, and iron. In the “core accretion” model of planetary formation, a rocky core gradually forms when dust grains that make up the disk of material that surrounds a young star bang into each other to create small rocks known as “planetesimals”. Citing this model, Johnson and Li stress that heavier elements are necessary to form the dust grains and planetesimals which build planetary cores.

Additionally, evidence suggests that the circumstellar disks of dust that surround young stars don’t survive as long when the stars have lower metallicities. The most likely reason for this shorter lifespan is that the light from the star causes clouds of dust to evaporate.

Read More

Image Info:

Artist’s concept showing a young Sun-like star surrounded by a planet-forming disk of gas and dust.

Image Credit: NASA/JPL-Caltech/T. Pyle

(via astronautjimblows)

itsfullofstars:

Jupiter’s Melting Heart Sheds Light on Mysterious Exoplanet

Scientists now have evidence that Jupiter’s core has been dissolving, and the implications stretch far outside of our solar system.

Jupiter might be having a change of heart. Literally.

New simulations suggest that Jupiter’s rocky core has been liquefying and mixing with the rest of the planet’s innards. With this new data, astronomers hope to better explain a recent puzzling discovery of a strange planet outside of our solar system.

“It’s a really important piece of the puzzle of trying to figure out what’s going on inside giant planets,” said Jonathan Fortney, a planetary scientist at the University of California Santa Cruz who was not affiliated with the research.

Keep reading.

the-star-stuff:

Surprise! Venus May Have Auroras Without a Magnetic Field

The same magnetic phenomenon that causes auroras on Earth has now surprisingly been discovered creating giant magnetic bubbles around Venus, a planet without a magnetic field.

These findings could help explain mysterious flashes of light fromVenus, in addition to the way comet tails work, researchers say.

Imaged Above: Venus’ southern hemisphere, as seen in the ultraviolet. CREDIT: ESA

(via itsfullofstars)

Could Ancient Aliens Live on Methuselah Planets?

The announcement of a pair of planets orbiting a 12.5 billion-year old star flies in the face of conventional wisdom that the earliest stars to be born in the Universe shouldn’t possess planets at all.

12.5 billion years ago, the primeval universe was just beginning to make heavier elements beyond hydrogen and helium, in the fusion furnace cores of the first stars. It follows that there was very little if any material for fabricating terrestrial worlds or the rocky seed cores of gas giant planets.

This argument has been used to automatically rule out the ancient and majestic globular star clusters that orbit our galaxy as intriguing homes for extraterrestrials.

The star that was announced to have two planets is not in a globular cluster (it lives inside the Milky Way, although it was most likely a part of a globular cluster that was cannibalized by our galaxy), but it is similarly anemic as the globular cluster stars because it is so old.

This discovery dovetails nicely with last year’s announcement of carbon found in a distant, ancient radio galaxy. These findings both suggest that there were enough heavy elements in the early universe to make planets around stars, and therefore life.

However, a Hubble Space Telescope search for planets in the globular star cluster 47 Tucanae in 1999 came up empty-handed. Hubble astronomers monitored 34,000 stars over a period of eight days. The prediction was that some fraction of these stars should have “hot Jupiters” that whirl around their star over a period of days (pictured here in an artist’s rendition). They would be detected if their orbits were tilted edge-on to Earth so the stars would briefly grow dimmer during each transit of a planet.

A similar survey of the galactic center by Hubble in 2006 came up with 16 hot Jupiter planet candidates. This discovery was proof of concept and helped pave the way for the Kepler space telescope planet-hunting mission.

Why no planets in a globular cluster? For a start, globular clusters are more crowded with stars than our Milky Way — as is evident in the observation of the dwarf galaxy M9 below. “It may be that the environment in a globular was too harsh for planets to form,” said Harvey Richer of the University of British Columbia. “Planetary disks are pretty fragile things and could be easily disrupted in such an environment with a high stellar density.”

However, in 2007 Hubble found a 2.7 Jupiter mass planet inside the globular cluster M4. The planet is in a very distant orbit around a pulsar and a white dwarf. This could really be a post-apocalypse planet that formed much later in a disk of debris that followed the collapse of the companion star into a white dwarf, or the supernova explosion itself.

Hubble is now being used to look for the infrared glow of protoplanetary disks in 47 Tucanae. The disks would be so faint that the infrared sensitivity of the planned James Webb Space Telescope would be needed to carry out a more robust survey.

If planets did form in the very early in the universe, life would have made use of carbon and other common elements as it did on Earth billions of years ago. Life around a solar-type star, or better yet a red dwarf, would have a huge jump-start on Earth’s biological evolution. The earliest life forms would have had the opportunity to evolve for billions of years longer than us.

This inevitably leads to speculation that there should be super-aliens who are vastly more evolved than us. So… where are they? My guess is that if they existed, they evolved to the point where they abandoned bodies of flesh and blood and transformed themselves into something else — be it a machine or something wildly unimaginable.

However, it’s clear that despite (or, because of) their super-intelligence, they have not done anything to draw attention to themselves. The absence of evidence may set an upper limit on just how far advanced a technological civilization may progress — even over billions of years.

Keep in mind that most of the universe would be hidden from beings living inside of a globular star cluster. The sky would be ablaze with so many stars that it would take a long time for alien astronomers to simply stumble across the universe of external galaxies — including our Milky Way.

There will be other searches for planets in globular clusters. But our present understanding makes the question of a Methuselah civilization even more perplexing. If the universe made carbon so early, then ancient minds should be out there, somewhere.

Perhaps they really are “vast, cool, and unsympathetic,” as science fiction writer H.G. Wells once put it.

Image credit: NASA

quantumaniac:

Happy Birthday NASA!

Fifty-three years ago today, on October 1st, 1958; NASA became an operational and fully functioning governmental administration. 

(via )

lookatthesefuckinstars:

Jupiter’s Clouds from Cassini

Cassini and Jupiter are two of my favorite things.

<3

(via )

New Photos Show Blazingly Bright Uranus & Neptune in Infrared

The distant “ice giant” planets Uranus and Neptune look like worlds aflame in new photos captured by Hawaii’s Keck Observatory.

To the naked eye, Neptune would appear blue and Uranus bluish-green. But Caltech astronomer Mike Brown snapped the new pictures in infrared light, using Keck’s adaptive optics system. So the two planets blaze reddish-orange, like embers glowing in the dark night of deep space.

Brown posted the pictures via Twitter from Sept. 18 to Sept. 20. Two shots show bright streaks on Neptune, which is about 17 times as massive as Earth and orbits 30 times farther from the sun than our planet does.

Read More of The Photogenic Infrared Duo

(Source: ikenbot, via myheadisweak)