ISRO plans missions to study exoplanets, dying stars after Chandrayaan-3 success

After the Chandrayaan-3 success, a mission to look for planets with a liveable atmosphere outside the Solar System is on the radar of the Indian Space Research Organisation (ISRO), with the space agency outlining the contours of such a search.

“We are conceiving a satellite called ExoWorlds, a mission for looking at exo-solar planets or planets that are outside our solar system and orbiting other stars,” ISRO chairman S Somanath said at a lecture at the Indian National Science Academy here.

“Nearly 5,000 exoplanets have been discovered so far and closer to one hundred may be habitable because of the atmosphere similar to the Earth.”

Radiations coming out of a star get modified while passing through the atmosphere. In the planned exoplanet mission – yet to be approved by the Union Cabinet – the space probe will study the spectral characteristics of such lights to find out if they match the signatures generated by the Earth.

For the atmospheric characterization of the exoplanets, the Indian payload will analyse the radiation in infra-red, optical and ultraviolet spectrum. “Such characterisation can tell us what the atmosphere of those liveable planets are made of,” Somanath said.

The orbiter of the Chandrayaan-3 mission – separated from the lander module on August 17 and circling the Moon while looking at the Earth – carries a unique payload designed to find out the signatures of Earth-like planets with potential for habitability.

Somanath said the plans for a Mars Lander Mission too were at the conceptual stage while two payloads for the proposed Venus mission were getting ready even as ISRO was in the process of approaching the Centre for an approval for the Venus mission.

Venus has an atmospheric pressure 100 times that of Earth near the surface, but the reasons for such high atmospheric pressure near the Venusian surface remains unknown. Also thick clouds enveloping Venus are full of acid and one cannot even penetrate the surface.

"It is important to understand the evolution of planetary bodies like Venus. Only if you look at Venus and Mars one can actually study what effects are there in your activities on the earth that actually makes it habitable or non-habitable,” Somanath said

ISRO’s deep space adventure for this year has not yet ended as the space agency is set to launch the X-ray Polarimeter Satellite or XpoSAT in December to understand mysteries associated with dying stars.

He said the XPoSat mission was ready for launch in December this year. The 450 kg satellite carries two instruments to measure the polarisation of bright X-ray pulsars and to understand the mechanism of bright black hole sources.

The XpoSat will measure polarisation as an additional property of cosmic X-ray sources, expanding the understanding of celestial bodies releasing such radiations. Currently, X-ray sources are measured for energy, time, and location.