asdfoster:

I'm not convinced that this is a second Earth yet.

There is still no indication that this is a rocky planet. Many of the super earths that we have found have turned out to be gaseous sub-neptunes. For example, the closest discovered planet to this one in terms of radius is Kepler 138c, which has a density of ~1.9g/cc. For reference, if the planet was entirely rock (no metal core), it would have a density of about 3g/cc. Iron has a density of 8g/cc. Kepler 138c must have an extensive atmosphere to have that low of a density; it is a gas ball much like Neptune (density 1.6g/cc).

There are many other planets that are this size that are also gas balls, and a few that are rocky as well. We don't know if this planet is rocky or gaseous yet. We don't know anything about it other than that it is in the habitable zone around a sun-like star.

If this planet is rocky, then get excited for the JWST or TMT to look at it when either of those are built so that we can analyze its atmosphere.

Don't get your hopes up too high for now though.


posted by j4d3: 1159 days ago