Carl Ziegler

Two new planets are circling dim red stars. One is nearly the size of Earth, the other is three and a half times larger. Both lie in what astronomers call the warm zone: a region where starlight doesn't scorch the surface but also doesn't leave it in perpetual cold. The host stars are red dwarfs, the most common stars in the galaxy.

NASA's TESS space telescope monitors thousands of stars, catching the moment when a planet crosses its star's disk — the star's light dims slightly. That's how astronomers spotted two planets orbiting stars similar to our Sun. One, TOI-883 b, completes an orbit in ten days; the other, TOI-899 b, takes nearly thirteen.

A ball, almost weightless for its size, circles its star every four days. Planet TOI-2195 A b is a real riddle: by mass it's slightly heavier than Neptune, yet bloated to Jovian volumes. If there were an ocean big enough, this exoplanet would float on its surface like a giant inflatable ball.