On June 24, 2026, NASA reported that its TESS space telescope had helped scientists find two very strange planets: TOI-791 b and TOI-791 c. They orbit a Sun-like star about 1,113 light-years from Earth. Both planets are close to Jupiter in size, but they are far lighter. Because of this, NASA says they are the “puffiest” planets ever found. Their density is so low that people compare them to cotton candy. (science.nasa.gov)

A planet like this is often called a “super-puff,” or a “cotton candy planet.” It looks big, but it has very little mass. NASA says TOI-791 b has only about 3.0% of Jupiter’s mass, and TOI-791 c has about 5.9%, even though one is nearly Jupiter’s size and the other is even bigger. The two planets take 139 days and 232 days to go around their star. Scientists found them by watching the star become a little dimmer when the planets passed in front of it. (science.nasa.gov)

These planets are exciting because scientists still do not fully understand how worlds like this are made. NASA has studied other cotton candy planets before, especially in the Kepler-51 system. Those planets are also large but very light, and Hubble observations suggested that some may have thick clouds or hazy skies high above them. The new TOI-791 planets may help scientists solve the same mystery. NASA says future studies may show what their atmospheres are made of and how these unusual planets formed. For English learners, this story is a fun reminder that science can be surprising: sometimes a giant planet can be as light as candy. (science.nasa.gov)