Miscellaneous wrap-up

As noted earlier, I missed posting more the last few weeks due to being sick, but here is a condensed summary of some of the other recent interesting updates as we come to the end of 2010…

Does Pluto, of all places, have a subsurface ocean? This new report says maybe; Cassini has found new evidence for an ice volcano on Titan; the building blocks of life could possibly form on Titan’s surface more easily than thought if there is any liquid water temporarily on the surface from ice volcano eruptions (or comet impacts); there’s a new theory on how Iapetus may have obtained its odd equatorial ridge; the “arsenic life” discovery continues to be criticized by some other scientists (see also here) while the scientists involved have responded and rebutted those claims (see also here); the Spitzer space telescope has found the first known carbon-rich exoplanet; a fourth large exoplanet has been photographed orbiting a star 129 light-years from Earth; another smaller exoplanet, a “super-Earth” was found to have an atmosphere with either high clouds or hot steam; a new study says that the entire Tharsis Rise on Mars should be named the largest known volcano in the solar system instead of the current Olympus Mons (one of four volcanoes that are part of Tharsis Rise); the warm fissures on Enceladus, the source of its water-ice geysers, were seen up-close by Cassini again; there may be another Jupiter-sized planet hiding out in the outer solar system; and finally, the current known exoplanet count is now 516 (and the hope was for at least 500 by the end of this month)!

Highlighted by, among other things, the next exoplanet update from Kepler in February and the launch of Curiosity, the next bigger and better Mars rover, in November, 2011 should also be an interesting year…

Two steps closer to finding another Earth

This past week, there were two more news items of great interest relating to exoplanets, and the search ultimately for another Earth-like planet.

The first, from the Kepler mission, is that the previously reported possible planet Kepler 9d, only 1.5 times larger than Earth, is likely to soon be announced as confirmed. Other news from the mission will also be announced in November according to the same update.

Artist's conception. Credit: Lynette Cook

Then, another very significant announcement from ground-based observatories at the University of California Santa Cruz, the University of Hawaiʻi at Mānoa and the Carnegie Institution of Washington, that for the first time, a small rocky planet has been confirmed orbiting well within the “habitable zone” of a nearby star, the region where temperatures would allow liquid water to exist on a planet; not too hot and not too cold. One of six known planets orbiting the red dwarf star Gliese 581, about 20 light years away, it is estimated to have a mass about three times that of Earth, and a diameter of only about 1.2 to 1.4 times that of Earth. Additional reports here, here and here. A good quote from the UCSC article indicates how planets like this are probably quite common:

The researchers also explored the implications of this discovery with respect to the number of stars that are likely to have at least one potentially habitable planet. Given the relatively small number of stars that have been carefully monitored by planet hunters, this discovery has come surprisingly soon.

“If these are rare, we shouldn’t have found one so quickly and so nearby,” Vogt said. “The number of systems with potentially habitable planets is probably on the order of 10 or 20 percent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that’s a large number. There could be tens of billions of these systems in our galaxy.”

This also brings the total count of known exoplanets so far to 492 and we’ve still only scratched the surface…