However more research is still needed to confirm that these exoplanets exist Astronomers found the first two exoplanets in 1992 These exoplanets look nothing like Earth They orbit a dead star When a star dies its center sometimes collapses into a dense glowing cinder This type of leftover star is very different from the sun Scientists were surprised to find planets orbiting these remnants Three years later scientists found an exoplanet moving around a star similar to the sun But this exoplanet is quite different from Earth The exoplanet travels around its star in only four days That means it orbits very close to its star Because it is so close to its star the exoplanet is much hotter than Earth In addition the exoplanet weighs as much as Jupiter That means it is more than 300 times as massive as Earth
A KELT 9b right the hottest exoplanet discovered so far is even warmer than some stars This type of large hot planet is known as a hot Jupiter During the next decade astronomers found many other large hot exoplanets Some are so close to their stars that their surfaces are hot enough to melt iron
The Hubble Space Telescope orbits 353 miles 569 km above Earth's surface In the mid 2000s scientists began finding large exoplanets that are farther from their stars Some of these planets were much farther from their stars than Pluto is from the sun These exoplanets were found using the Hubble Space Telescope The Hubble Space Telescope was launched into space in 1990 It has been orbiting
Earth ever since As it orbits the telescope takes pictures of planets stars and other objects in space Because the telescope is above Earth's atmosphere the pictures are much clearer than pictures taken from Earth's surface Scientists study the pictures to learn about outer space Sometimes they find exoplanets In the pictures the exoplanets look like very faint glowing objects around the stars So far Earth is the only planet scientists know of that has life But discoveries of the 2010s came closer to finding planets that are similar to Earth A few of these planets are the same size as Earth Some have signs of an atmosphere They may even have water Water was critical for the development of life on Earth Scientists now know of more than 50 exoplanets that may be able to support life
