At present researchers have detected more than four hundred planets going round other stars, but modern technology does not yet make it possible to study the surface of a planet and the processes going on there. Only in a few isolated cases have astronomers managed to study some characteristics of the atmosphere of exoplanets (most often gas giants with the mass of Jupiter and greater).
The authors of the new work have proposed a technology that will make it possible to “catch” the aftermath of eruptions on other planets with the help of powerful telescopes. The scientists analysed the eruptions that take place on the Earth and came to the conclusion that the most reliable sign of volcanic activity is sulfur dioxide. This gas is thrown into the atmosphere in enormous quantities during eruptions, and an excess of it will indicate that there are active volcanoes on the exoplanet.
The presence of volcanoes on exoplanets can be “told” by sulfur dioxide, enormous quantities of which are thrown into the atmosphere during an eruption. As things stand today, however, astronomers have no instruments that would let them record an excess of sulfur dioxide, since the concentration of the gas remains small by cosmic standards even after a powerful eruption.
The scientists have calculated that the new James Webb telescope, which is to take the place of the Hubble, will be able to “see” the traces of an eruption at least ten times more powerful than the eruption of Mount Pinatubo in 1991 - one of the strongest of the 20th century. The volcano would have to be on a planet no more than 30 light years from the Earth.
The launch of the James Webb telescope is planned for 2014. Its orbit will be at a height of 1.5 million kilometres - the telescope, the main mirror of which is 6.5 metres in diameter (for comparison, the diameter of the Hubble's mirror is 2.4 metres), will be placed at one of the Lagrange points of the Earth-Sun system.