
ALT A member of the payloads team holds the Snoopy doll inside the lobby of the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center on Jan. 5, 2023, after unpacking the doll from his transport case. Snoopy is wearing an orange flight suit and is smiling in the pair of gloved hands. A model of the Orion spacecraft can be glimpsed in the background. Credit: NASA/Isaac Watson
Why is Venus Called Earth’s Evil Twin? We Asked a NASA Scientist

ALT Illustration of Kepler 138, a red dwarf star located 218 light-years away. The low density of Kepler-138 c and Kepler-138 d – which are nearly identical in size – means that they must be composed largely of water. They are both twice Earth's mass but have roughly half of Earth's density, and therefore cannot be solid rock. This is based on measurements of their mass versus physical diameter. They are considered a new class of "water planet," unlike any major planet found in our solar system. Kepler-138 b is one of the smallest exoplanets known, having the mass of the planet Mars and the density of rock. Credits: NASA, ESA, and Leah Hustak (STScI)


















