Putting an end to decades of doubt and debates, scientists have finally found evidence that there is not just frozen water on the surface of Mars, there actually is a massive reservoir-like catchment of liquid water just under the surface of the red planet.
Richard Zurek, the chief scientist in the Mars program office at NASA's Jet Propulsion Laboratory in Pasadena, California, said the complex, nearly chaotic structure of the ice caps could affect the radar signals in unexpected ways.
Orosei said the water in the Martian lake was below the normal freezing point but remained liquid thanks in large part to high levels of salts. "The concept of liquid water somewhere on Mars leads one to believe that there may be an environment that would harbor extent life".
But the climate has changed significantly over the course of the planet's 4.6 billion year history and liquid water can not exist on the surface today, so scientists are looking underground. It was home to plenty of liquid water and lakes at least 3.6 billion years ago. Between 2012 and 2015, the spacecraft confirmed the existence of the bright reflections during 29 passes over the south polar region.
Jonathan Lunine, director of the Center for Astrophysics and Planetary Science at Cornell University, who was not involved with the research, said the finding transforms Mars from a dusty planet to yet another "ocean world" in the solar system. The depth of the water is not known. Life has been found in the poisonous, arsenic-rich waters of Lake Mono, California.
A dose of realism: Liquid water in large quantities could be a real boon to any future Martian colonists. Though they did not find signs of even microorganisms, the images and data they transmitted back to Earth shaped both the scientific understanding and popular conception of the red planet.
Scientists Roberto Orosei (L), Elena Pettinelli (C) and Enrico Flamini pose near a replica of the Cosmo Sky Med satellite before a news conference where they announce after first-time detection of liquid water on Mars by italian radar Italian radar MARSIS, on board the ESA's Mars at the Italian Space Agency headquarter in Rome, Italy July 25, 2018. "We can show that there's enough energy to drive chemotrophic life-life that doesn't need sun, but lives on chemistry", he said.
The region corresponded to a basin, adding to speculation that liquid water had flowed into this spot. Further investigation revealed a roughly 12 mile wide area located around one mile below the planet's icy surface which produced a radio profile similar to that of one of Earth's subglacial lakes.
For as long as anyone can remember, Mars was the planet that scientists, astronomers and stargazers looked to and wondered 'is there life out there?'.
"It will require flying a robot there, which is capable of drilling through 1.5 kilometres of ice", he explained. And finding liquid water beneath the surface of Mars, specifically under ice sheets, is exactly what scientists and engineers had hoped MARSIS would do. Data from NASA's Cassini orbiter, even though the mission ended in 2017, continues to provide researchers with evidence of organics under the ice of Saturn's moon Enceladus, although they can't yet tell if geology or biology produced those organics (Cassini simply wasn't equipped to tell the difference).