Bortom vårt solsystem har numera fler än 5 000 planeter observerats. Milstolpen nåddes tidigare i veckan då Nasas planetarkiv utökades med ytterligare 65 exoplaneter, som de kallas.
Overview
Most of the exoplanets discovered so far are in a relatively small region of our galaxy, the Milky Way. We know from NASA’s Kepler Space Telescope that there are more planets than stars in the galaxy.
By measuring exoplanets’ sizes (diameters) and masses (weights), we can see compositions ranging from very rocky (like Earth and Venus) to very gas-rich (like Jupiter and Saturn). Exoplanets are made up of elements similar to those of the planets in our solar system, but their mixes of those elements may differ. Some planets may be dominated by water or ice, while others are dominated by iron or carbon. We’ve identified lava worlds covered in molten seas, puffy planets the density of Styrofoam and dense cores of planets still orbiting their stars./NASA
