Kepler- 22b
The planet's first transit in front of its host star was observed on Kepler's third day of scientific operations in mid-2009,[9]. The third transit was detected in late 2010. Additional confirmation data was provided by the Spitzer Space Telescope and ground-based observations. On December 5, 2011, the confirmation of the existence of Kepler-22b was announced.[8]
[edit]Composition and structure
[pic]
[pic]
A diagram of the Kepler-22b System, compared to our Inner Solar System.
Kepler-22b's radius is roughly 2.4 times the radius of Earth. Its mass and surface composition remain unknown,[8][7] with only some very rough estimates established: It has less than 124 Earth masses at the 3 sigma confidence limit, and less than 36 Earth masses at 1 sigma confidence.[6]
It is thought that the object has a mass similar to that of Neptune[10] (~35 Earth masses[11]). Another possibility is that Kepler-22b is an "ocean-like" world. It might also be comparable to the water-rich planet GJ 1214 b although Kepler-22b, unlike GJ 1214b, is in the habitable zone. If it has an Earth-like composition, the compression of material in the interior of the planet would give an overall mass greater than 4 Earth masses [12]. Such a planet would also produce surface gravity greater than 7 times that on Earth. This is ruled out to at least 1-sigma uncertainty by radial velocity measurements of the system [6], suggesting Kepler-22b does not have Earth-like composition. It is likely to have a more volatile-rich composition with a liquid or gaseous outer shell[8]; this would make it similar to Kepler-11f, the smallest known gas planet.
"If it is mostly ocean with a small rocky core," Natalie Batalha, one of the scientists on the project, speculated "it's not beyond the realm of possibility that life could exist in such an ocean."[13] This possibility of life has spurred SETI to perform research on top candidates for extraterrestrial intelligence.[14] However, if the planet's carbon
[edit]Composition and structure
[pic]
[pic]
A diagram of the Kepler-22b System, compared to our Inner Solar System.
Kepler-22b's radius is roughly 2.4 times the radius of Earth. Its mass and surface composition remain unknown,[8][7] with only some very rough estimates established: It has less than 124 Earth masses at the 3 sigma confidence limit, and less than 36 Earth masses at 1 sigma confidence.[6]
It is thought that the object has a mass similar to that of Neptune[10] (~35 Earth masses[11]). Another possibility is that Kepler-22b is an "ocean-like" world. It might also be comparable to the water-rich planet GJ 1214 b although Kepler-22b, unlike GJ 1214b, is in the habitable zone. If it has an Earth-like composition, the compression of material in the interior of the planet would give an overall mass greater than 4 Earth masses [12]. Such a planet would also produce surface gravity greater than 7 times that on Earth. This is ruled out to at least 1-sigma uncertainty by radial velocity measurements of the system [6], suggesting Kepler-22b does not have Earth-like composition. It is likely to have a more volatile-rich composition with a liquid or gaseous outer shell[8]; this would make it similar to Kepler-11f, the smallest known gas planet.
"If it is mostly ocean with a small rocky core," Natalie Batalha, one of the scientists on the project, speculated "it's not beyond the realm of possibility that life could exist in such an ocean."[13] This possibility of life has spurred SETI to perform research on top candidates for extraterrestrial intelligence.[14] However, if the planet's carbon