Planets: Rocky, Smaller than Earth, Three of Them

"Smallest Alien Planets, Real-Life 'Tatooines' Highlight Huge Week of Exoplanet Finds"
Denise Chow, Space.com (January 12, 2012)

"The ongoing hunt for planets beyond our solar system turned up some big results this week.

"One team of researchers found the three smallest alien planets yet detected, and another group announced two new worlds orbiting double-star systems — the real-life incarnations of the fictional planet Tatooine from 'Star Wars.' Further, yet another study determined that our Milky Way galaxy likely harbors at least 160 billion exoplanets.

"The smallest known exoplanets orbit a single star, called KOI-961, which is located about 120 light-years away. The smallest world in the three-planet system is roughly the size of Mars, researchers said...."

First off, about that "Tatoonine" thing. Kepler-35 b and Kepler-34 b each orbit double stars: sort of like Luke Skywalker's home in "Star Wars," except Kepler 35 b is the size of Saturn, and neither are particularly hospitable for life-as-we-know-it. Which the "Star Wars" Tatooine was, by comparison.

That said, this month's news about exoplanets - planets that orbit another star - makes it more likely that there's life elsewhere in the universe. Or less unlikely, anyway.

That's because the three new worlds mentioned are - probably - small and rocky. Like Earth. It's starting to look like planets more-or-less like Earth may be fairly common. Or not all that uncommon, anyway.

The three featured planets orbit KOI-961. For now, they're called KOI-961.01, KOI-961.02, and KOI-961.03. They're between the size of Mars and Earth, almost certainly rocky worlds, and orbit a star that's only about 70% wider than Jupiter.

"...'It's actually more similar to Jupiter and its moons in scale than any other planetary system,' [California Institute of Technology's John] Johnson said in a statement. 'The discovery is further proof of the diversity of planetary systems in our galaxy.'..."
(Space.com)

Exciting times.

Related posts:

• "Exoplanets: Over 700 Found to Date; Latest Batch of 18 are Jupiter-Size"
  (December 5, 2011)
• "Gliese 581d: Rocky, Close (sort of), and Liquid Water (could be, maybe)"
  (May 18, 2011)
• "GJ 1214b: Water in the Atmosphere; Close; and No Vacation Destination"
  (February 23, 2011)
• "Kepler 11: A Tightly-Packed Planetary System"
  (February 2, 2011)
• "Life on Other Worlds: First, Find a Planet"
  (January 1, 2011)

More in this blog:

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"