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.

Exoplanet Mapping

It's not the easiest task in the world, and the result is less than spectacular, but Hubble has taken the best weather map of an exoplanet to date.  The planet is WASP-43B, a hot Jupiter with twice Jupiter's mass that takes only 19 hours to orbit its star.  In the sun, temperatures reach 3,000 degrees Fahrenheit, while the night half is only a third of that, at 1,000 degrees Fahrenheit.  That's almost cold right there.

Hubble was also able to find water vapor in the planet's atmosphere, which doesn't do the planet much good, seeing as it's hot enough to melt quite a lot of metals, let alone water, but it does mean that we can detect water vapor in the atmospheres of exoplanets, which will come in handy whenever we start peering at smaller, cooler worlds.  You know, ones that might have life.

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A Little Blue Dot

http://www.cnn.com/2013/07/11/world/space-blue-planet/index.html?hpt=hp_c4

 I'm a big follower of the search for exoplanets, so I just found this fascinating.  The article is about a planet that the Hubble Space Telescope was able to image 63 light years away.  Hubble didn't image the planet directly, but rather was able to discern the planet's color using the spectrum of light reflected off the planet surface as it orbited the star.  As the planet went behind the star, there was a noticeable drop in the blue portion of the spectrum, indicated the planet is blue in color.  That doesn't mean the planet is covered in water.  No, the planet is what is known as a "hot Jupiter," a gas giant that orbits very close to its star, and is several thousand degrees Fahrenheit.  This particular planet orbits about 3 million miles away from its star, a tenth of the distance between Mercury and our sun.  Scientists guess the planet is about 2,000 degrees Fahrenheit, and that any rain would be liquid glass.  Now, this is obviously not a nice place, but the fact that we can do this is remarkable science.  The precision of the Hubble is remarkable, despite its age.  The news about exoplanets has been getting steadily more exciting as time goes on, I look forward to hearing the next story on them.