Researchers peek into atmosphere of ‘super Earth’; observe wildly changing temperatures
Astronomers have, for the first time ever, found direct evidence of temperature changes in a distant super Earth located some 40 million light years away thereby marking an important milestone in identifying habitable planets outside our solar system by being able to peek into the atmospheres of rocky ‘super Earths’ and observe conditions on their surfaces.
The multi-university study led by researchers at University of Cambridge used NASA’s Spitzer Space Telescope to observe thermal emissions coming from the planet dubbed 55 Cancri e – orbiting a sun-like star located 40 light years away in the Cancer constellation – over the course of two years and for the first time found direct evidence of rapidly changing conditions, with temperatures on the hot ‘day’ side of the planet swinging between 1000 and 2700 degrees Celsius.
Researchers have said that this huge variability in temperatures is still under investigation, but chances are that the changes in the readings could be due to huge plumes of gas and dust that blanket the surface, which may be partially molten. These plumes, researchers believe, are resulting from the massive amounts of volcanic activity on the surface.
“We saw a 300 percent change in the signal coming from this planet, which is the first time we’ve seen such a huge level of variability in an exoplanet,” said Dr Brice-Olivier Demory of the University’s Cavendish Laboratory, lead author of the new study. “While we can’t be entirely sure, we think a likely explanation for this variability is large-scale surface activity, possibly volcanism, on the surface is spewing out massive volumes of gas and dust, which sometimes blanket the thermal emission from the planet so it is not seen from Earth.”
55 Cancri e
The 55 Cancri e is one of the five planets orbiting a star 40 light years away and has been pegged as a ‘super Earth’. The exoplanet, which is about twice the size and eight times the mass of Earth, has a rocky surface and resides so close to its parent star that a year lasts just 18 hours.
Researchers have also revealed that the planet is tidally locked, meaning that it doesn’t rotate like the Earth does – instead there is a permanent ‘day’ side and a ‘night’ side. Since it is the nearest super Earth whose atmosphere can be studied, 55 Cancri e is among the best candidates for detailed observations of surface and atmospheric conditions on rocky exoplanets.
Researchers have been studying the 55 Cancri e and results indicated abundance of carbon with diamond being pegged as a major component that makes up the planet. However these claims have been weakened owing to latest observations of high temperature variations thereby opened up new questions.
“When we first identified this planet, the measurements supported a carbon-rich model,” said Madhusudhan, who along with Demory is a member of the Cambridge Exoplanet Research Centre. “But now we’re finding that those measurements are changing in time. The planet could still be carbon rich, but now we’re not so sure.”