Many Earth-sized planets out there…

A new NASA survey indicates that Earth-sized planets are now thought to be common in the galaxy, and thus, probably the universe. As many as one in four stars similar to the sun could have Earth-sized planets orbiting them.


Credit: NASA/JPL & Caltech/UC Berkeley

From the press release:

Nearly one in four stars similar to the sun may host planets as small as Earth, according to a new study funded by NASA and the University of California.

The study is the most extensive and sensitive planetary census of its kind. Astronomers used the W.M. Keck Observatory in Hawaii for five years to search 166 sun-like stars near our solar system for planets of various sizes, ranging from three to 1,000 times the mass of Earth.

All of the planets in the study orbit close to their stars. The results show more small planets than large ones, indicating small planets are more prevalent in our Milky Way galaxy.

“We studied planets of many masses — like counting boulders, rocks and pebbles in a canyon — and found more rocks than boulders, and more pebbles than rocks. Our ground-based technology can’t see the grains of sand, the Earth-size planets, but we can estimate their numbers,” said Andrew Howard of the University of California, Berkeley, lead author of the study. “Earth-size planets in our galaxy are like grains of sand sprinkled on a beach — they are everywhere,” Howard said.

The study is in the Oct. 29 issue of the journal Science.”

See also the University of California press release. These findings would appear to confirm the preliminary findings from the Kepler space telescope as well, in that smaller rocky worlds are more common than larger gas giants, which bodes well in the search for life.

Watch Curiosity grow

The next Mars rover, Curiosity, is being built right now in the clean room at NASA’s Jet Propulsion Laboratory in Pasadena, CA and you can watch the progress live on the new webcam!.

Curiosity is scheduled to be launched late next year and land on Mars in August 2012. It is also much larger than the two previous rovers, Spirit and Opportunity, at 10 feet long, 9 feet wide and 7 feet tall. It is nuclear powered, so not dependent on solar panels for energy and hosts a geology lab, including rock-vaporizing lasers and the cameras can take both high-resolution photos and video. It will search for evidence of past or present conditions suitable for life.

Weird warm spot on an exoplanet

As more exoplanets are found on virtually a weekly basis, it is becoming apparent how diverse they are, sometimes with peculiar characteristics not seen before. Such is the case with the large “hot Jupiter” planet upsilon Andromedae b, which orbits very close to its star and so is searingly hot on the side facing the star (it keeps the same side toward the star, as the moon does as it orbits the Earth). Well, not quite. For some reason, the “hot spot” with the highest temperature is about 80 degrees away, almost on the other side of the planet.


Credit: NASA/JPL/Caltech

The observations were made using the Spitzer Space Telescope, and astronomers don’t have an explanation yet, but theories include supersonic winds and star-planet magnetic interactions.

Into the depths of a Martian canyon

Valles Marineris is a huge rift valley on Mars, a canyon system dwarfing the Grand Canyon on Earth. A portion of it, Melas Chasma, is featured in new images from the Mars Express spacecraft. In this spot, the canyon is about 9 kilometres (5.6 miles) deep, and sulphate deposits are evidence of a former lake. There are also other water-cut channels in the immediate vicinity. There are additional and larger images, including 3D perspectives, here.

Credit: ESA/DLR/FU Berlin (G. Neukum)

Perhaps the proposed Martian airplane will fly over this area for even better views…?

Extensive carbonate deposits reported on Mars

According to a new paper published in Nature Geoscience, large deposits of carbonates have been found buried about six kilometres (four miles) below the surface of Leighton crater (exposed by the original impact), near the huge shield volcano in the Syrtis Major region. Small deposits have been found before on the surface, including recently by the rover Spirit, but much larger amounts would be additional evidence of a warmer, wetter ancient Mars, with a thicker atmosphere of carbon dioxide. Notably, carbonates are formed in non-acidic (alkaline) liquid water. So this finding would again reinforce the idea of ancient lakes, seas or oceans on the surface. But were those waters cold or warm? What about those icebergs? It seems like every time another piece of the puzzle is found, it just raises more questions…

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