Scientists have shown that water is likely to be a major component of those exoplanets (planets orbiting other stars) which are between two to four times the size of Earth. It will have implications for the search of life in our Galaxy. The work is presented at the Goldschmidt conference held recently in Boston.
A new evaluation of data from the exoplanet-hunting Kepler Space Telescope and the Gaia mission indicates that many of the known planets may contain as much as 50% water. This is much more than the Earth’s 0.02% (by weight) water content. “It was a huge surprise to realise that there must be so many water-worlds,” said lead researcher Dr Li Zeng of Harvard University.
Scientists have found that many of the 4,000 confirmed or candidate exoplanets discovered so far fall into two size categories: those with the planetary radius averaging around 1.5 that of the Earth, and those averaging around 2.5 times the radius of the Earth.
Now a group of international scientists, after analysing the exoplanets with mass measurements and recent radius measurements from the Gaia satellite, have developed a model of their internal structure.