The Strange, Misshapen Orbits of Planet-Forming Disks in a Triple-Star System

Whatever we grow up with, we think of as normal. Our single solitary yellow star seems normal to us, with planets orbiting on the same, aligned ecliptic. But most stars aren’t alone; most are in binary relationships. And some are in triple-star systems.

And the planet-forming disks around those three-star systems can exhibit some misshapen orbits.

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Did Jupiter Push Venus Into a Runaway Greenhouse?

Venus has been garnering a lot of attention lately, though primarily in the scientific community as the last Hollywood movie about the planet was released in the 1960s.  This is in part due to its dramatic difference from Earth, and what that difference might mean for the study of exoplanets.  If we can better understand what happened during Venus’ formation to make it the hell scape it is today, we might be able to better understand what truly constitutes the habitable zone around other stars.

Numerous planetary scientists have focused on Venus’ formation and atmospheric development in the recent past.  Now a new paper posits that Venus might have had liquid water on its surface as recently as one billion years ago.  And a contributor to the disappearance of that water might be an unlikely culprit: Jupiter.

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A Strange Planet has been Found that’s Smaller than Neptune But 50% More Massive

Astronomers have found another strange exoplanet in a distant solar system. This one’s an oddball because its size is intermediate between Earth and Neptune, yet it’s 50% more massive than Neptune.

Astronomers have found what they call “puff planets” in other Solar Systems. Those are planets that are a few times more massive than Earth, but with radii much larger than Neptune’s. But this planet is the opposite of that: it’s much more massive than Neptune, but it also has a much smaller radius. Super-dense, not super-puffy.

This oddball planet is calling into question our understanding of how planets form.

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A Group of Meteorites All Came From a Destroyed Planetesimal With a Magnetic Core

Before our Solar System had planets, it had planetesimals. Scientists think that most of the meteorites that have struck Earth are fragments of these planetesimals. Scientists also think that these planetesimals either melted completely, very early in their history, or that they remained as little more than collections of rocks, or “rubble piles.”

But one family of meteorites, that have been found spread around the world, appear to come from a planetesimal that bucked that trend.

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More Details On NASA’s VERITAS Mission, Which Could Go to Venus

Venus has always been a bit of the odd stepchild in the solar system.  It’s similarities to Earth are uncanny: roughly the same size, mass, and distance from the sun.  But the development paths the two planets ended up taking were very different, with one being the birthplace of all life as we know it, and the other becoming a cloud-covered, highly pressurized version of hell.  That cloud cover, which is partially made up of sulfuric acid, has also given the planet an air of mystery. So much so that astronomers in the early 20th century speculated that there could be dinosaurs roaming about on the surface.

Some of that mystery will melt away if a team from NASA’s Jet Propulsion Laboratory gets a chance to launch their newest idea for a mission to the planet, the Venus Emissivity, Radio Science, InSAR, Topograph, and Spectroscopy (or VERITAS) mission.

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Pluto and Other Kuiper Belt Objects Started Out With Water Oceans, and Have Been Slowly Freezing Solid for Billions of Years

It seems unlikely that an ocean could persist on a world that never gets closer than 30 astronomical units from the Sun. But that’s the case with Pluto. Evidence shows that it has a sub-surface ocean between 100 to 180 km thick, at the boundary between the core and the mantle. Other Kuiper Belt Objects may be similar.

But time might be running out for these buried oceans, which will one day turn to ice.

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Planets Form in Just a Few Hundred Thousand Years

Astronomers like to observe young planets forming in circumstellar debris disks, the rotating rings of material around young stars. But when they measure the amount of material in those disks, they don’t contain enough material to form large planets. That discrepancy has puzzled astronomers.

The answer might come down to timing.

A new study suggests that planets form much quicker than astronomers think.

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Space Dust Delivered Water to Vesta, Could it Have Done the Same for Earth?

One of the most enduring questions about Earth regards the origins of its water. Where did it come from? One widely-held theory gives comets the honor of bringing water to Earth. Another one says that Earth’s water came when a protoplanet crashed into early Earth, not only delivering a vast quantity of water, but creating the Moon.

Now a new study shows that the minor planet Vesta got its water from space dust. Could that help explain the origin of Earth’s water?

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Huge Stars Can Destroy Nearby Planetary Disks

Westerlund 2 is a star cluster about 20,000 light years away. It’s young—only about one or two million years old—and its core contains some of the brightest and hottest stars we know of. Also some of the most massive ones.

There’s something unusual going on around the massive hot stars at the heart of Westerlund 2. There should be huge, churning clouds of gas and dust around those stars, and their neighbours, in the form of circumstellar disks.

But in Westerlund 2’s case, some of the stars have no disks.

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