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A water body exists below the Martian south polar ice cap.

Without water, no form of life as we know it could exist. There is therefore great interest in detecting liquid water on other planets of our Solar System. Landforms such as dry river valleys and lakes show that liquid water must have been present on Mars in the past (1). Nowadays, small amounts of gaseous water exist in the Martian atmosphere, and some water ice is found on the planet’s surface. Water droplets were seen condensing onto the Phoenix lander (2), and there may be reoccurring water activity on slopes during the Martian summer (3). However, stable bodies of liquid water have not been found on Mars. Published in Science’s First Release this week, Orosei et al. (4) report an analysis of radar data from the Mars Express mission that shows the existence of stable liquid water below 1.5 km of ice, close to the Martian south pole.

Ice caps similar to those on Earth exist at the Martian north and south poles, known as the North and South Polar Layered Deposits (NPLD and SPLD, respectively). More than 30 years ago, Clifford hypothesized that liquid water might be present below the Martian polar ice caps (5). Despite mean annual air temperatures of around −60°C, lakes exist below Earth’s Antarctic ice sheet (6). Glacier ice insulates the bed from the cold surface. Thus, temperatures at the base of the Antarctic ice sheet, which may be as thick as 4.8 km, can reach the pressure melting point of water; the melting point is reduced owing to the pressure of the ice layer above. Water at the ice base reduces basal friction, leading to increased flow speeds. Finding liquid water below the Martian ice caps might solve ongoing debates about whether the NPLD ice flow is due to ice deformation, deformation of the bed, or gliding over the bed or whether it is not flowing at all (7).

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A radar instrument on one of the oldest operational Mars orbiters has discovered possible evidence of present-day liquid water on Mars.

Liquid water on Mars? Again? Yes, again. The announcement came at a press briefing held by the Italian Space Agency in Rome, concerning a paper published today in Science.

How is today’s water-on-Mars hoopla different from all of the past announcements? In brief: the evidence is from a new instrument, examining a new location on Mars, and it’s the first place we’ve seen evidence for a present-day body of water that is liquid and stays liquid. For years.

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Dreaming is one of the strangest things that happens to us, and for as long as we have been recording history, we have been puzzling over why our minds are so active while we sleep.

Finally, new research claims to have evidence as to what dreaming is all about — and it will probably surprise no one.

According to a team from The Swansea University Sleep Lab in the UK, dreaming really does help us process the memories and emotions we experience during our waking lives.

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Scientists announced Wednesday that they’ve found evidence of a large body of water beneath the surface of Mars. It may not be little green men, but it’s pretty darn cool.

The announcement, which comes less than two months after the Curiosity Rover found evidence of organic molecules on Mars, adds one more piece to the puzzle for scientists searching the planet for signs that it could support life — or at least could have in the past. And while scientists have long known that Mars used to have liquid water billions of years ago, the fact that it could still have water is a big deal since there’s a possibility that this water may host living organisms.

The researchers involved in the discovery, a team of Italian astronomers and physicists, published their findings in a paper in the journal Science. In the paper, the team presents evidence collected from May 2012 to December 2015 by the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment aboard the Mars Express spacecraft that shows evidence of a large body of liquid water.

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