Nov 152017

A new potentially Earth-like exoplanet has been announced, Ross 128 b. It’s 10.89 light years away (12th closest star system to Earth), the planet masses about 1.35 Earths and is in the inner edge of the habitable zone, getting about 1.38 time the solar radiation as Earth. Ross 128 is a red dwarf, so:

1: the”year” is only 9.86 days

2: The planet very probably doesn’t have a moon due to the close distance to the star

3: The planet is probably tidally locked, or in some rotational resonance

Fortunately, Ross 128 is a very quiet and well-behaved red dwarf, unlike Proxima Centauri which is constantly having massive flares. So while Proxima b almost certainly has long since had any atmosphere stripped away, Ross 128b, if it had an atmosphere, has a good chance of still having it.

Ross 128 is also an old star, meaning lots of hydrogen and helium and little else. Which *may*mean that the planetary system *may* also be low in the heavier metals. So even though Ross 128 b is more massive than Earth, if it doesn’t have as heavy of a nickel-iron core, the bulk density could be far lower and the surface gravity could be Earthlike. But without a metal core the chances of a magnetosphere are greatly reduced, especially if it only rotates every 9.86 days. Without a magnetosphere, the atmosphere has undoubtedly suffered and the surface will be badly irradiated.

 Posted by at 10:26 pm
  • publiusr

    An old folks home then–for when the sun dies.