Scientists confirm existence of new 'waterworld' planet GJ1214B

The video discusses the exoplanet GJ1214B, which is a water world with a thick, steamy atmosphere. It is about 2.7 times the Earth's diameter and has a mass seven times greater. Observations using the Hubble telescope suggest that a significant portion of the planet's mass is composed of water.

Describe the atmosphere of Exoplanet GJ1214B.

What is the composition of a large fraction of GJ1214B's mass?