Researchers have investigated the chemical composition in the atmosphere of 19 exoplanets. In fourteen of them, large amounts of water vapor were detected.
The University of Cambridge has led a team of scientists who have looked at atmospheric data from 19 exoplanets to compile the temperatures and chemistry of the planets. It is the most thorough study of its kind.
The study included everything from small versions of Neptune that are only ten times larger than Earth, to super-Jupiter whose size is 600 times larger than our own planet.
The temperature range of the planets has been between comfortable 20 degrees and a glass-melting heat of 2,000 degrees. Of course, the most interesting aspect was the presence of water. The researchers conclude that the presence of water vapor is not uncommon in the planet’s atmosphere. It was found in large quantities in 14 of the 19 planets, along with copious amounts of sodium and potassium in six of them.
The project is led by researcher Nikku Madhusudhan at the Department of Astronomy at Cambridge. Five years ago he was the first to measure larger amounts of water vapor in the lower atmosphere of very large exoplanets.
Science has predicted that giant planets of this type should also have a high proportion of oxygen, since the substance is the third most common in the universe, after hydrogen and helium. In such an atmosphere, this would mean that water, which is a dominant carrier of oxygen, can also be expected to be abundant.
Now, scientists have collected numerous spectroscopic images from space telescopes, including Hubble and Spitzer, as well as from ground-based telescopes such as the Very Large Telescope in Chile and Gran Telescopio Canarias on Spanish soil.
The breadth of available observations, together with detailed calculation models, statistical methods and the properties of sodium and potassium atoms, meant that the team was able to make qualified estimates of the chemistry in the planets’ atmosphere.
– Being able to measure the chemicals that are found in large quantities in exoplanets’ atmospheres is something extraordinary. This is because we have not yet managed to do the same for the giant planets in our own solar system, including Jupiter, our nearest gas giant, says Luis Welbanks, Cambridge researcher and lead author of the article, in a statement.
The results have been published in The Astrophysical Journal Letters. The study is part of a five-year research program on the chemical composition of planets outside our own solar system.