Planet Earth’s Cousin May Contain Life - Hailed as “Kepler 452b”

[RavenSky]

This came across my Twitter feed this morning with the above hyperbolic headline. When I tracked it back to the original source, it's actually almost a year old and with a substantially more conservative headline - but still very interesting:

[YOUTUBE]
https://www.youtube.com/watch?v=RGB36b0nZ8Q[/YOUTUBE]

 

[Tom Sawyer]

It's probably just all evil, goateed versions of us, anyways, so no need to get overly excited about it.

 

[fromderinside]

Yeah. Probably. After all when gravity and distance are about the same nucleic acids congregate. Doubtless evil agency.

 

[Angry Floof]

WOOOT! How soon will I be able to go for a visit, and do they have Ben & Jerry's Cherry Garcia?

 

[lpetrich]

Using this paper on exoplanet mass-radius calculations at Sara Seager's pages, I find these possible masses. Fitting to 1.63 Earth radii,

Composition	Mass (Me)
Fe(0.3) / MgSiO3(0.7)	6.31
Fe(0.225) / MgSiO3(0.525) / H2O(0.25)	3.89
Fe(0.065) / MgSiO3(0.485) / H2O(0.45)	2.89
Fe(0.03) / MgSiO3(0.22) / H2O(0.75)	2.30

The composition is by mass, and the planet is layered. The MgSiO3 here is magnesium silicate in perovskite structure, an approximation of the Earth's mantle's composition.

Using that paper's calculations, I find 0.96 Earth radii for 1 Earth mass, or 1.11 Earth masses for 1 Earth radius.

Using the 0.3/0.7 number, the planet's surface gravity is 2.37 times the Earth's, or 23.3 m/s^2. Also, the low-orbital and escape velocities are 1.97 times the Earth's, or 15.6 km/s and 22.1 km/s. It will be awfully hard to depart from that planet.

There is at least one known exoplanet that is likely to be a super-ocean world: GJ 1214b ( Gliese 1214 b), so there is a chance that this planet may also be such a world.