COLDEST PLANET

Neptune is an ice giant and is considered the coldest planet in the Solar System, with a surface temperature of -200 degrees Celsius. The previous holder of this title was Pluto, which has a surface temperature of -225 degrees Celsius, but it was demoted to a dwarf planet in 2006. The main reason that Neptune is so cold is because of its distance from the Sun. As the most distant known planet in our Solar System, it receives the least amount of heat from the Sun’s rays. Neptune’s atmosphere is made of hydrogen, helium and a little methane, which can maintain a gas state under the planet’s freezing temperatures. Even though the methane present in Neptune’s atmosphere acts as an insulating blanket, as it does on Earth, the trace amounts mean Neptune can’t stay as warm as the methane-abundant Uranus, at -195 degrees Celsius.