Sub-Earth' exoplanet discovered around the closest solo star to us

[Admin]

Astronomers have discovered a low-mass "sub-Earth" planet orbiting the closest solo star to the solar system, Barnard's star, that has a year lasting just three Earth days.

Sub-Earth' exoplanet discovered around the closest solo star to us : Read more

 

[Helio]

Astronomers have discovered a low-mass "sub-Earth" planet orbiting the closest solo star to the solar system, Barnard's star, that has a year lasting just three Earth days.

Sub-Earth' exoplanet discovered around the closest solo star to us : Read more

Curious that it took this long to find it given it's a close neighbor.

But it has a solar equivalent distance of 0.41, so it gets a little more than the scorching radiation that Mercury does. But it is, no doubt, tidally locked, hence the cool side might have some interesting places to visit.

 

[billslugg]

"Nobody goes there any more. It's too crowded" - Y.Berra

 

[Helio]

"Nobody goes there any more. It's too crowded" - Y.Berra

Yes, but when it comes to a fork in the road, they seem to take them.

 

[billslugg]

When you live on a tidally locked planet with a 4 day year, the inhabitable zone would be a narrow strip around the edge. You might get just enough light reflected down into your lair to stay warm but not enough to kill you. Librations would be highlighted on the evening news when previously shaded areas were expected to receive sunlight. "Burn warning in sector four after 3PM!! Bring in your mutant plants!"

 

[Unclear Engineer]

Joking aside, would a planet that close to a red dwarf even be expected to retain an atmosphere for long enough to evolve life?

I did not see anything that indicated any interest in trying to find life on that planet.

My reading of the importance of this discovery was more along the lines that a rocky planet still formed around a small "metals-poor" star, and that indicated something important for scientists who are trying to understand how planets evolve from clouds of gas and dust as they form stars.

 

[Helio]

Besides at the terminator, there does seem to be some additional hope for Mercury-like planets (hot and tidally locked). The tidal-lock allows the dark side to be frozen, but it doesn't prevent subsurface water, including liquid water, which is maintained by interior heating.

Larger ones in tight orbits have been found with atmospheres. I think one was found to have atmospheric winds over 20k mph. Atmospheres may have the ability to reduce the temperature differences enough to allow surface water.

What is needed for any real hope for habitability seems to be "shelter, energy, nutrients, and sources of carbon" (P148). A great deal of liquid water is being found on planets (including Mercury) and moons (e.g. our Moon). The moons may be more favorable since they benefit the most from tidal friction, thus can stay warm enough to keep water liquid for "billions of years".

The more ubiquitous these requirements are found, the more optimistic scientists become. Certainly reasonable, but until some hard evidence is found for current or prior living organisms elsewhere, and not from Earth contaminates, then this is still a hypothesis in waiting, IMO.