> If a super-Earth is ejected from its star system and has a dense atmosphere and watery surface, it could sustain life for tens of billions of years, far longer than life on Earth could persist before the sun dies.

What would be the energy source to sustain life on an ejected super-Earth? Radioactivity? Tidal forces from orbiting moons?

I suppose one cannot expect anything better from a site called singularity hub, but this post is disingenuous (or written by an actual hack) for multiple reasons. Aren’t the majority of planets we are discovering all orbiting red dwarfs, which can exhibit massive swings in luminosity and be very violent? Even the example quoted by the author which such a short radius seems one of them. Also what do you do in a tidally locked planet? Half if not 90 % of it is likely to be unsustainable.

Also a rogue planet without a star might be able to sustain simple life but without human sources of nuclear power the only source of energy would be geothermal, so not exactly exciting candidates for living. Also who wants to live in a planet in perpetual darkness?

Either the “astronomer” author wasn’t a real astronomer at all or this is just clickbait.

Imagine being intelligent life on a super earth 2.5-3x larger than earth but trapped on the planet due to gravitational forces.
This is exciting, but I think I'm most excited about learning to make self-sufficient and self-replicating colonies in space.

If we focus on settling planets, then each planet is its own set of problems.

But if we focus on learning to live in space, then although it may be harder initially, it's a single problem to solve. Then we just keep working and improving on that solution. And there's a lot more space out there than there are habitable planets. And there's a lot more matter and energy out there than are available on those planets.

Interesting idea.

To me, exoplanet surveys are one of the most exciting forms of science. I can think of no other thing that would bring us closer to understanding whether or not life does exist in our universe beyond us.

I've long held that it does, but it feels to me that belief is practically religious, completely unfounded. Combined with the fact that I think no other event will impact our world for the better more than knowing this universe has other life... I have my fingers crossed for the giant ground-based teles they listed at the end. Godspeed

It's interesting that planets could roam between solar systems for 10's of billions of years before becoming uninhabitable, and that such planets are likely common.
> By definition, super-Earths have many of the attributes of a super habitable planet.

Is that true?


> A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively.[1] The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability.

Super Earths are easy to find and super common but I am almost betting the most life will be found in gas giant moons. Even though we don’t have any gas giants in our own system that have Earth-sized rocky moons, each one of ours has half a dozen “almost-there” moons. A civilisation developing around a gas giant with multiple habitable and easily accessible moons would be very interesting.
> While there are many reasons why a habitable world would not have signs of life, if, over the coming years, astronomers look at these super habitable super-Earths and find nothing, humanity may be forced to conclude that the universe is a lonely place.

Interesting... The "no" is definitely cheaper and faster than the "maybe" or "yes." If we get a "no", what's next? Planet-wide depression?

> So the most habitable planet would have roughly twice the mass of Earth and be between 20 to 30 percent larger by volume.

So, ~60% denser than Earth? Density is mass/volume, and 2x / 1.25x = 1.6x.

The math works out really well if they meant a 20-30% larger radius: 1.25*3 = 1.95, so similar density but larger volume.

Wouldn't it be physically impossible to escape the gravity of a super Earth using the currently available and known propulsion technology we have here on Earth?
If they're bigger then they have more mass and therefore a higher gravitational pull, which makes every task more expensive.
so we probably are not alone. the next questions for me are: how rare is first "one-way" contact between intelligences? and how rare is asynchronous two-way contact (centuries or milllenia in between messages) and how rare is two way immediate contact in our galaxy?
Apparently there is high interest in finding life elsewhere in our galaxy, or in other galaxies.

Since a lot of such interest is resulting in US federal government funding and I am a US citizen, I have standing, if only as a taxpayer, in this interest.

About this interest and paying to pursue it with my tax money, I ask "Why should I?".

I confess that getting good evidence of such life would be curious, entertaining, fun, etc.

For any in doubt, I will just stipulate that there is a lot of life out there in our galaxy and the rest of the galaxies in the universe. Done. No more wondering or arguing. If you want, I'll also stipulate that they are all little, green, and have 10 legs and 5 eyes. And I will agree that we might find evidence of a Dyson sphere (build a sphere around a sun and collect all or a lot of the energy it radiates).

Second, but I will insist that, from all we know about physics now, there is no way for us ever to have anything like practical two way communications with any life that evolved outside of our solar system.

Third, with current physics, the search for life is at best just curious, entertaining, fun, etc., and, sorry, on these criteria some good movies are better! I can buy a good movie on a DVD for about $10 -- so if I give $10 for the search for that life, I'm all paid up?

Fourth, really, then, the search for such life needs to include a search for some radical new physics. If want to pursue promising research directions in such physics, okay by me, but such research efforts should be low budget unless very promising, and I doubt that there will be any promising directions.

So, net, whatever astronomy, astrophysics, etc. are good for, the search for life that evolved outside of our solar system is not very serious -- or, such life IS there but with current physics there are no significant consequences for us. Sorry 'bout that.

Or, a big effort on the search for such life looks to me like some researchers want to do a big selling job to get taxpayers to give them an interesting career. Sorry 'bout that.

Or, if the search for life is mostly just for a search for some radical new physics, then sell the effort as a search for the physics, not the life. Or I agree already that there is a lot of life out there, but with our current physics there are no consequences for us -- stipulate that they are all green with 5 eyes and get no conflicting data.

What does "more habitable than earth" even mean? Habitable to whom?
We didn't evolve there so we most likely couldn't survive there. And these planets are so distant we will almost certainly never visit there. Essentially nothing more than entertaining pipe dreams...
The actual title "Super-Earths Are Bigger and More Habitable Than Earth, and Astronomers Are Discovering More of the Billions They Think Are Out There" is doubtless too long for HN, but the mangler truncated it at the "Di" of "Discovering", which is surely suboptimal.