The first exoplanet that JWST found has no atmosphere.

Above: Artist's impression of exoplanet LHS 475 b

Even the perfect size of an exoplanet doesn't guarantee that there are lifeforms. The exoplanet LHS 475 b is 99% of Earth. But the problem is that it doesn't have an atmosphere at all. Or an extremely thin atmosphere. In the last case, the planet captures star wind around it. That means the extremely thin atmosphere could be external. And that is a remarkable thing. The LHS 475 b orbits the red dwarf star in the Octans constellation 41 light years from Earth. 

 Even large rocky planets can be without an atmosphere. And that expands our knowledge of planets. The exoplanet LHS 475 b is the first exoplanet found by the JWST telescope. But that planet is extremely hostile to lifeforms. So even a large size doesn't guarantee that the exoplanet has an atmosphere. 

But the reason for the lost atmosphere is also interesting. The lack of atmosphere can be the reason for the lack of a magnetic field. In that case, the solar wind blows the atmosphere away. And if that thing is true, there is a possibility that the planet is a so-called "zombie world" where is no radioactive material left. 

And that thing means that the LHS 475 b could be a very old planet. There is a possibility that this exoplanet is sometimes born near some other star. And then supernova- or nova eruption pushed it away from its orbiter. Then another star could capture that rogue planet. Those kinds of things are making LHS 475 b very interesting. 

https://astrobiology.com/2023/01/webb-discovers-lhs-475-b-an-earth-sized-rocky-planet.html

https://bigthink.com/starts-with-a-bang/no-atmosphere-jwst-exoplanet/

https://webbtelescope.org/contents/media/images/2023/102/01GNVWTAZKPVD1GNC0HZF52YTB

https://shorttextsofoldscholars.blogspot.com/