What we learned from the video:
Planet X is 10 x the mass of Earth , it is roughly the same size of Neptune. It is made mostly of hydrogen and helium. It takes 15,000 years to orbit the sun. Neptune takes 165 years. A lot like Neptune Planet X will be found using mathematics. Scientists believe we will find Planet X in the next 5 years and when we do we will gladly welcome Planet X to the solar system.
Gilese 436 b was the 1st hot Neptune ever found. It is about the size of Neptune and it is an expoplanet orbiting the red dwarf Gilese 436.
Gliese 1214 b is an expo planet that orbits the star Gliese 1214 and was found Dec. 2009. its parent star is 42 light years from our sun, in the constellation Ophiuchus.
There are more planets we did not research. One of them is WASP-12 b.It is super hot because it is very close to its star, so close that the star is eating it. In 10 million years the star will swallow it whole