Physicists and astronomers have been on the hunt for habitable planets out there in the universe for decades, now.

One of the hurdles with this search is that we still don’t have a really good understanding of how a planet becomes habitable, or any real way of predicting which will be and which won’t.

This exoplanet, dubbed “Phoenix,” should have been barren rock but it isn’t.

Scientists are hoping if we can figure out how and why, it could go a long way in helping us to a better understanding.

TIC365102760 b, or Phoenix, is smaller, hotter and older than anyone expected for its class. It’s six times closer to its star than Mercury is to the sun.

Not only that, it’s star is a red giant, the next phase in our own Sun’s evolution.

The proximity to this powerful star should have stripped Phoenix of its atmosphere, yet is hasn’t.

And lead author Sam Grunblatt would really love to know the answer(s) as to why.

“This planet isn’t evolving the way we thought it would, it appears to have a much bigger, less dense atmosphere than we expected for these systems. How it held on to that atmosphere despite being so close to such a large host star is the big question.”

NASA’s Transiting Exoplanet Survey Satellite originally spotted the planet, which is roughly the size of Neptune.

But while there are other worlds like that, Phoenix is 60 times less dense than any other.

“It’s the smallest planet we’ve ever found around one of these red giants, and probably the lowest mass planet orbiting a red giant star we’ve ever seen. That’s why it looks really weird. We don’t know why it still has an atmosphere when other ‘hot Neptunes’ that are much smaller and much denser seem to be losing their atmospheres in much less extreme environments.”

While Phoenix will inevitably be swallowed by its star – as will Earth – but in the meantime the atmosphere here is being stripped very slowly.

The potential implications for our own planet definitely intrigue the authors here.

“We don’t understand the late-stage evolution of planetary systems very well. This is telling us that maybe Earth’s atmosphere won’t evolve exactly how we thought it would.”

And here we were all sure we had about 5 billion years to figure it out.

Give or take.

If you thought that was interesting, you might like to read about the mysterious “pyramids” discovered in Antarctica. What are they?