New Delhi: Where are scientists looking for signs of life outside earth? Mars to start with, but moons of Jupiter and Saturn are getting attention, too.

Jakob Van Zyl, an associate director of Project Formulation and Strategy at National Aeronautical and Space Administration’s (NASA) jet propulsion laboratory, provided some clues during a lecture at American Centre.

“We are looking, studying the entire universe. Trying to find habitable zones, but we are also looking at our own solar system, Mars and Europa in particular," Zyl told Mint.

Habitable zone is the region around a star where the average temperature on a planet allows for liquid water which could sustain life. The habitable zone in our solar system is from the orbit of Venus to just outside the orbit of Mars. Zyl explained that it has been established that there is very little chance of finding liquid water in Venus and various missions are looking to find if life ever existed on Mars. Outside the solar system, Kepler Space telescope has found 4,175 candidate planets out of which 268 are in habitable zones of stars. More than 1,000 of these are confirmed planets.

“The next step is to try and find if we can actually find signs of life. We want to take pictures of those planets and analyse them and to see what they’re made of and to see if the right kind of gases are present in the atmosphere that can sustain life," said Zyl.

Zyl explained that Nasa scientists are not just looking at habitable zones, but others. Jupiter’s moon Europa is one focus of research. Covered with ice, Zyl said that it is likely to have liquid oceans more than 100km deep. Even though this moon is not in the habitable zone, liquid water exists because the gravitational pull of Jupiter is heating up the interior of the pool. “A lander is proposed to see the composition of ice. We will launch probably in the 2020-23 time frame, so we will get there late in the 2020s," Zyl said.

There is also Saturn’s moon Enceladus. Last year, Nasa researchers in a scientific paper showed the moon’s outer ice shell is not frozen solid to its interior, and that a global ocean must be present in that moon.

“Are we alone? You be the judge," he left an open-ended conclusion.

Meanwhile, for Mars, Nasa is developing the capabilities needed to send humans to an asteroid by 2025 and Mars in the 2030s. Could Indians be a part of it?

“Collaboration maybe not be there in the 2020 Mars mission as that is already decided. Later on in this decade, it is definitely a possibility," Zyl said.