As the hunt for planets outside our solar system continues,we have discovered many other worlds with extreme features. Scientists recently discovered the hottest planet ever found-with a surface temperature greater than some stars.The ongoing exploration of our own solar system has revealed some pretty weired contents too. Here is the list of seven most extreme planet.
In our own solar system,mercury is the closest planet to the sun at a mean distance of 57,910,000km.Temperatures on its dayside reach about 430 degree Celsius,the sun has its surface temperature of 5,500 degree Celsius.
The stars HD 195689- also known as KELT-9-is 2.5 times more massive than the sun and has a surface temperature of almost 10,000 degree Celsius.One of its planet,KELT-9b,is much closer to its host star than mercury is from the sun.
KELT-9b,is a Jupiter-type gas giant.It is shrivelling away as the molecules in its atmosphere are breaking down to their constituent atoms-and burning off.
OGLE-2005-BLG-390Lb is the coldest planet having the temperature of just 50 degree above absolute zero- -223degree Celsius.It is a rocky planet too having about 5.5 times the Earth’s mass.Its host star is a low mass,cool star known as a res dwarf.In reference to an icy planet in the star wars franchise,the planet is popularly referred to as Hoth.
Common stars like our sun burn by fusing hydrogen into helium.But there is a form of star called a brown dwarf,which are not large enough to sustain but big enough to start fusion processes.Planet DENIS-P J082303.1-491201 b with the equally alias 28.5 times the mass of Jupiter-making it the most massive planetlisted in NASA’s exoplanet archive.Because of its massive mass it is still debateable whether its actually a planet or should be classified as dwarf star.
Kepler-37b is the smallest exoplanet,just slightly larger than our moon and smaller than mercury.It is closer to its host star than mercury is from the sun which makes it too hot to support liquid water and the life on its surface.
About 12.7 billion years old PSR B1620-26 b, is the oldest known planet.A gas giant 2.5 times the mass of Jupiter it is around forever.PSR B1620-26 b has two host stars rotating around each other named neutron star and a white dwarf,which are what left when a star has burned all its fuel and exploded in supernova.It doesn’t contain enough of heavy elements such ascarbon and oxygen needed for life to evolve.
V830 Tauri is the only 2m years old.The host star has the same mass as our sun but twice the radius,which means it has not yet fully contracted into its final shape.The planet-a gas giant with three-quarters the mass of Jupiter- is probably still growing which means it is acquiring more mass by frequently collision with other planetary bodies like asteroids-making it an unsafe place to be.