Planets like Earth live in the “Goldilocks zone” — the region around a star where conditions are most comfortable for life. But most planets aren’t so cushy. They’re either far away and cold, or close in and hot. And some are so close that they’re being vaporized by their star.

One example is WASP-69 b. It orbits a cool, faint star about 160 light-years from Earth. The system is in the constellation Aquarius, which is in the southeastern sky at dawn tomorrow.

WASP-69 b is only a few million miles from its parent star. At that close range, its atmosphere is heated to more than a thousand degrees Fahrenheit. The heat has caused the planet to puff up. While it’s only about a quarter as massive as Jupiter, the giant of our own solar system, it’s actually a little bigger than Jupiter.

That makes it easy for the star to blow away material from the planet’s atmosphere. That gives WASP-69 b a long “tail” like that of a comet. Recent observations found the tail is at least 350,000 miles long — greater than the distance from Earth to the Moon.

Even so, the rate at which the planet is vaporizing is pretty slow. It’s losing enough mass to make a planet as heavy as Earth every billion years or so. Considering that WASP-69 b is about 90 times the mass of Earth, this big, hot planet won’t disappear anytime soon.

We’ll have more about exoplanets tomorrow.

Script by Damond Benningfield