It’s not exactly the Hollywood fantasy of flying saucers beaming down big-headed, wide-eyed aliens to Earth, but top NASA scientists have announced that they think we are tantalizingly close to discovering some form of extraterrestrial life. In fact, our search tools have become so sophisticated that space researchers believe we will have gathered convincing data for the presence of alien life, most likely microbial, by 2025.

“I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years,” NASA chief scientist Ellen Stofan said this week at a public panel discussion in Washington. “We know where to look. We know how to look. In most cases, we have the technology, and we’re on a path to implementing it.”

This optimism was promoted by recent discoveries that suggest that potentially habitable worlds are much more common than once believed. Almost every star is now thought to host planets, and one study even suggested that those within our galaxy possess an average of two planets within the habitable range, or “Goldilocks zone,” which is the area where liquid water can exist.

But it’s not just stars that can host these regions; discoveries much closer to home suggest that even giant planets could have habitable zones, which could greatly expand scientists’ search for life. Jupiter’s icy moon Europa, for example, has a vast and deep subsurface ocean despite residing some 400 million miles away from the sun. The water within this ocean resists completely freezing over due to strong tidal forces resulting from Jupiter’s gravitational pull. Jupiter is also home to another interesting satellite, Ganymede, which is also thought to possess a subsurface saltwater ocean.

Although Europa has received the most attention, Saturn’s moon Enceladus also recently became a top candidate for extraterrestrial life following the discovery of a liquid water ocean below its icy surface. Furthermore, this satellite was also found to possess geysers that spurt out sandy plumes of water and ice, suggesting the presence of hydrothermal activity within the subsurface ocean.

And let’s not forget about Mars; this now parched and barren planet was once a watery world complete with enduring lakes, oceans and flowing rivers, some of which could have lingered long enough for life to have had a chance to evolve. Not only that, but scientists also recently found evidence of useful nitrogen compounds, which are a crucial source of this element for life on Earth.

While our present set of powerful observatories are obviously capable of churning out exciting data on the subject, things are only set to get more exciting as technology develops. A mission to Europa is already on the cards, for example, which NASA hopes to launch by 2022. And before that, the agency hopes to send up their James Webb Space Telescope, which will probe the atmospheres of nearby “super-Earths,” or exoplanets with masses higher than our own planet, with the hope of identifying gases that could have been created by life forms. Certainly, we have got a lot to look forward to in the coming years.

[Via space.com, LA Times and PopSci]