Tag Archives: habitable zone

Using Kepler astronomers have found a solar system with five terrestrial-type planets, with two in the habitable zone.

Eden? Using Kepler astronomers have found a solar system with five terrestrial-type planets, with two in the habitable zone.

Using observations gathered by NASA’s Kepler Mission, the team, led by William Borucki of the NASA Ames Research Center, found five planets orbiting a Sun-like star called Kepler-62. Four of these planets are so-called super-Earths, larger than our own planet, but smaller than even the smallest ice giant planet in our Solar System. These new super-Earths have radii of 1.3, 1.4, 1.6, and 1.9 times that of Earth. In addition, one of the five was a roughly Mars-sized planet, half the size of Earth. …

The two super-Earths with radii of 1.4 and 1.6 Earth radii orbit their star at distances where they receive about 41% and 120%, respectively, of the warmth from their star that the Earth receives from the Sun. The planets are thus in the star’s habitable zone; they have the right temperatures to maintain liquid water on their surfaces and are theoretically hospitable to life.

Theoretical modeling of the super-Earth planets, Kepler-62e and Kepler-62f, suggests that both could be solid, either rocky–or rocky with frozen water.

This is big news. Additional info can be found here and here.

The Kepler science team today revealed an additional 461 candidate exoplanets, with four being less than twice Earth’s size and in the habitable zone.

Worlds without end: The Kepler science team today revealed an additional 461 candidate exoplanets, with four being less than twice Earth’s size and in the habitable zone.

Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. The most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively. The new data increases the number of stars discovered to have more than one planet candidate from 365 to 467. Today, 43 percent of Kepler’s planet candidates are observed to have neighbor planets.

Of these candidates, 105 have so far been confirmed to be exoplanets by other methods.

Note that these Kepler planets are in addition to the fifteen new exoplanets noted in my previous post.

Another planet has been found in the habitable zone

Planets without end: Another planet has been found in the habitable zone.

Gliese 163c could have a size between 1.8 to 2.4 Earth radii, depending if it is composed mostly of rock or water, respectively. It receives on average 40% more light from its parent star than Earth from the Sun, making it hotter. In comparison, Venus receives 90% more light from the Sun than Earth. We do not know the properties of the atmosphere of Gliese 163c but, if we assume that it is a scaled up version of Earth’s atmosphere, then its surface temperature might be around 60°C [140°F]. Most complex life on Earth (plants, animals, and even humans) are not able to survive at temperatures above 50°C [122°F], however, plenty of extremophilic microbial life forms can thrive at those temperatures or higher.

One astronomer has found that the habitable zone around some smaller stars is smaller than first calculated because of tidal heating.

One astronomer has found that the inner edge of the habitable zone around some dwarf stars is smaller than first calculated because tidal forces overheat planets close to the star.

Then again, this heating might expand the habitable zone in other directions. Stars might overheat when close to the star, but get a boost of needed heat when they would normally be too far away.

Is it snowing microbes on Enceladus?

Is it snowing microbes on Enceladus?

“More than 90 jets of all sizes near Enceladus’s south pole are spraying water vapor, icy particles, and organic compounds all over the place,” says Carolyn Porco, an award-winning planetary scientist and leader of the Imaging Science team for NASA’s Cassini spacecraft. “Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth’s oceans.”

Another thousand exoplanets from Kepler

Kepler today released an updated catalog of candidate exoplanets observed during the space telescope’s first sixteen months of observations. In this release, they list more than a thousand new exoplanet candidates, almost two hundred of which are Earth-sized. Among the new exoplanet candidates, twenty-five are in the habitable zone!

Now for some details.
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Another superEarth has been found orbiting a star in the habitable zone.

Another superEarth has been found orbiting a star in the habitable zone.

An M-class dwarf star called GJ 667C, which is 22 light-years away from Earth, had previously been observed to have a super-Earth (called GJ 667Cb) that orbited the star in only 7.2 days, making it too close to the star, and thus too hot, to support life.

The study started with the aim of learning more about the orbit of GJ 667Cb. But the research team found a clear signal of a new planet (GJ 667Cc) with an orbital period of 28.15 days and a minimum mass of 4.5 times that of Earth.

Though the planet is much closer to its star than the Earth, the star itself is much smaller and dimmer, so overall the planet gets about the same amount of energy as the Earth.

From Kepler: Dozens of Earths in the habitable zone

At a press conference today the science team at Kepler announced a swath of new discoveries from the space telescope, all of which point to the impending discovery of multiple Earth-like planets capable of harboring life.
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A slew of exoplanets

Using two European-built ground-based telescopes in Chile, astronomers have announced today the discovery of 50 new exoplanets, 16 of which are considered super Earths, one of which is in the habitable zone of its star. You can read the preprint of their research paper here [pdf].
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