Hubble Spots Atmosphere Forming on Earth-Sized Exoplanet

Before you start packing your bags for GJ 1132b, be aware that, while it may be Earth sized and is forming an atmosphere, it's not going to be a nice place to visit. GJ 1132b is in very close orbit around a red dwarf, making a full orbit in a day and a half, is tidally locked, and the surface is almost certainly nothing but molten rock. And that fresh atmosphere is composed of hydrogen, hydrogen cyanide, methane, and ammonia, with a hydrocarbon haze to top things off. 

But it is interesting nonetheless because it shows that planets, even those super close to their stars, can reform an atmosphere. Scientists believe that GJ 1132b started out as a sub-Neptune, but that the initial hydrogen-helium atmosphere was lost when the planet moved in close, leaving the dense rocky core completely devoid of atmosphere. They think that the hydrogen was actually absorbed into the planet's surface and is being released by volcanism at a faster rate than the solar winds can strip away, leaving a thin atmosphere similar in pressure, if not composition, to Earth's. This is good news for finding habitable planets, because it shows that planets don't have to start out Earth-like to eventually become habitable. If these young sub-Neptunes can lose their thick atmosphere but regenerate a thinner one, they could eventually become nicer places to live once the solar system settles down. Hey, anything to boost the odds of finding a habitable exoplanet is good news.

Most of Earth's Heavy Elements Come From One Place

All of the matter in the universe heavier than hydrogen or helium was made after the Big Bang in stars. However, standard nuclear fusion can only produce elements as heavy as iron; once a star tries to start fusing iron, the fusion reaction requires more energy than it puts out, causing said star to go supernova. It's during the supernova that all the heavier elements are made, however, supernovae are not the only way heavy elements come into being. The collision of two neutron stars also produces heavy elements, and according to new research, such a collision was responsible for seeding our solar with a vast quantity (something like 1 quintillion tons) of heavy elements such as gold and uranium.

According to the scientists, the specific collision happened about 1,000 light years away from the stellar nebula that our solar system formed out of, and occurred about 80 million years before the sun was born. This conclusion was reached through analysis of ancient meteorites, and the elements leftover from radioactive decay within those meteorites. Those elements were consistent with what a neutron star collision would have produced, not a supernova.

While we should be grateful for that collision all those eons ago (specifically, the iodine produced is essential for life), if such an event happened at that proximity today, it would create a gamma ray burst that would essentially torch our atmosphere, causing a mass extinction. Well, if we were unlucky enough to be on the business end of one of the poles of the black hole that would be formed in the process. Fortunately, these things don't happen very often, so no need to worry.

The Moon's Creation May Not Have Been that Simple

And by simple, I mean the standing theory that the Moon was created when the early Earth was smacked by a similarly-sized object, splashing out large amounts of debris, which eventually coalesced into the Moon we know today. This theory does a good job of explaining why the Moon's orbit and the Earth's rotation time are getting longer, but it does have one big flaw. Namely, the whole "rogue planet coming up and hitting the Earth in just the right manner not to destroy it but also splashing out a bunch of debris to form the moon" is an unlikely scenario at best. It's not so much that it couldn't happen, but there may be a more plausible explanation.

To be honest, "Earth gets hit with many smaller objects instead of one really big one" isn't a drastic change in the theory. But it does make a lot more sense. The early solar system was a chaotic place, and a lot of objects hit a lot of other objects. Having a bunch of objects a few hundred or a thousand miles across hitting the Earth over the course of a few million years is perfectly natural considering the state of the early solar system. This isn't a new idea, but the main problem was that it didn't explain why the Moon and Earth were made of basically the same stuff, a problem that the giant impact theory covers. However, the scientists behind this new multiple-impact research believe that over time, the chemical imbalances would work themselves out. It's an interesting take on a surprisingly simple question: Where did the Moon come from?

In other space news, it's the 25th anniversary of the discovery of the very first exoplanets. Old PSR B1257+12 doesn't get a whole lot of credit, since it's a pulsar and the three planets surrounding it are constantly bathed in pulsar radiation (which is quite strong, if you don't know), but they were the very first. If nothing else, it showed that extrasolar planets do actually exist. I mean, of course they existed, but actual evidence is always better than theory. Fun fact, one of the two astronomers responsible for this discovery, Alex Wolszczan, is a professor at Penn State, and I actually was in one of his classes. It was basic astronomy, so it wasn't anything too interesting, but still, neat little tidbit there.

Expanding Ice in a Warming World

The planet is getting warmer. This is a fact, backed by data. This year is looking to be the warmest on record, even if the year doesn't end all that warm. However, it is important to note that despite this fact, the world has not gotten warmer overall, and that some regions may not behave how you might expect.

This year, Antarctic sea ice covered 7.72 million square miles, the biggest area since the 1970's, when accurate measurements began. It's theorized that changing wind conditions from global warming have caused cold air to move across the Ross Sea, allowing for large scale ice expansion, since there's no land to stop anything. Warm air has instead started moving across the Antarctic Peninsula, and it's worth noting that ice coverage in that area has shrunk from past years.

Another area that is not behaving as expected is half a world away, in the Himalayas. Glaciers in the Karakorum region are not shrinking like other glaciers in the area, and if anything, are expanding. As the planet warms, the Himalayas receive more moisture, and for most mountains, this moisture comes in the summer, as rain. Because of geography, the Karakorum receives most of its moisture in the winter, so it falls as snow, feeding the glaciers in the area.  So again, even though the area is warming, not everywhere behaves the same way. It is important to note that while some glaciers are expanding, many are not, and that some inconsistency does not mean global warming is not an issue. It would be more remarkable if every place on the planet was warming in the same way.