Tuesday, September 13, 2011

Strange worlds

Today's topic: planets and moons in recent news. 

The European Southern Observatory (located high in the Chilean mountains) just released its latest exoplanet survey results. Bottom line: about 50 new super Earths, one of these worlds arguably within its star's habitable zone. (That's not to say anyone knows that HD 85512 b is habitable -- we don't know whether it has an atmosphere. But if this world has an atmosphere, the current understanding of planetary dynamics says liquid water could exist on its surface.) From Space Daily, see: "Latest Exoplanet Haul Includes Super Earth At Habitat Zone Edge."

(That article spoke to me because the novel I'm currently writing involves a super Earth.)

Here's another -- and quite different -- exoplanet. Again from Space Daily, see, "Strange planet is blacker than coal." But TrES-2b is not a giant lump of something coal-like. It's a Jupiter-like gas giant, closely orbiting its star. About 3 million kilometers close, its atmosphere heated to 1000 degrees C! So how the blazes (heh!) is that world blacker than acrylic black paint?

 But worlds need not be anchored to stars. The latest observations suggest that more planets may roam free -- ejected from the solar systems of their birth, it is believed -- than otherwise. From Discovery Magazine and astronomer Phil Plait (of Bad Astronomy fame), see: "The galaxy may swarm with billions of wandering planets."

Closer to home, on the speculative side of the world-hunting biz, comes the notion (see Space.com) that a "Giant Stealth Planet May Explain Rain of Comets from Solar System's Edge." The newly launched WISE infrared observatory would be just the instrument to spot any such distant planet. The theory goes (see article for more) that a massive object far out in the (also speculative) Oort Cloud would explain rains of very-long-period comets. This theoretical remote super Jupiter reminds one of the older (and again, still theoretical) notion that our Sun has a dark companion star (nicknamed Nemesis) -- because a brown dwarf companion might also explain the long-period-comet phenomenon.

Yet closer to home, it seems Pluto has another moon. From a July NASA picture of the day, see Pluto and its four moons. For now, the newly discovered moon has the temporary name of P4. (Still, that beats HD 85512 b, doesn't it?)

Really close to home -- in space, if not time -- consider the proposal that Earth once had a second moon. From Time.com, see "Moon Jr.: Once Upon a Time, the Earth Had Two." The Moon has an odd mass distribution, the hidden (from Earth's point of view) side being quite different than what's visible from Earth. A collision between the Moon and Moon Jr. might explain that odd mass distribution. Personally, I'll wait for results from the recently launched, moon-interior-peeking Grail twin-probe mission before reading too much into Farside highlands.

And if that's not enough worlds in the news, I'll leave you with this composite representation (not photographs) of all the exoplanets discovered by NASA's Kepler probe as of February 1, 2011. All 1235 such worlds.(For a bit of explanation of the image, see "New Image Is Worth 1,235 Potential Alien Planets," from Live Science.)

For reading this far, consider yourself worldly-wise.

1 comment:

Erik said...

Phil Plait is talking about planets that roam free of their parent star? I'm not gonna be surprised if he steps into a transport booth some day and never comes out.