TAMPA-A massive underground lake has been detected for the first time on Mars, raising the possibility that more water - and maybe even life - exists there, international astronomers said Wednesday.

Located under a layer of Martian ice, the lake is about 12 miles (20 kilometers) wide, said the report led by Italian researchers in the US journal Science.

It is the largest body of liquid water ever found on the Red Planet. "Water is there. We have no more doubt," co-author Enrico Flamini, the Italian space agency's Mars Express mission manager, told a press conference.

Mars is now cold, barren and dry but used to be warm and wet. It was home to plenty of liquid water and lakes at least 3.6 billion years ago.

Scientists are eager to find signs of contemporary water, because such discoveries are key to unlocking the mystery of whether life ever formed on Mars in its ancient past, or if it might persist today.

"This is a stunning result that suggests water on Mars is not a temporary trickle like previous discoveries but a persistent body of water that provides the conditions for life for extended periods of time," said Alan Duffy, an associate professor at Swinburne University in Australia, who was not involved in the study.

Being able to access water sources could also help humans survive on a future crewed mission to Earth's neighboring planet.

This particular lake, however, would be neither swimmable nor drinkable, and lies almost a mile deep (1.5 kilometers) beneath the icy surface in a harsh and frigid environment.

Whether microbial forms of life could lie within is a matter of debate. Some experts are skeptical of the possibility since the lake is so cold and briny, and mixed with a heavy dose of dissolved Martian salts and minerals.

The temperature is likely below the freezing point of pure water, but can remain liquid due to the presence of magnesium, calcium, and sodium.

"This is a discovery of extraordinary significance, and is bound to heighten speculation about the presence of living organisms on the Red Planet," said Fred Watson of the Australian Astronomical Observatory.

"Caution needs to be exercised, however, as the concentration of salts needed to keep the water liquid could be fatal for any microbial life similar to Earth's," added Watson, who was not involved in the research.

The discovery was made using a radar instrument on board the European Space Agency's Mars Express orbiter, which launched in 2003.

The tool is called the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), and was designed to find subsurface water by sending radar pulses that penetrate the surface and ice caps.

MARSIS "then measures how the radio waves propagate and reflect back to the spacecraft," said the study.

These reflections "provide scientists with information about what lies beneath the surface."

A team of researchers led by Roberto Orosei of the Istituto Nazionale di Astrofisica in Bologna, Italy, surveyed a region called Planum Australe, located in the southern ice cap of Mars, from May 2012 until December 2015.

A total of 29 sets of radar samplings showed a "very sharp change in its associated radar signal," allowing scientists to map the outlines of the lake.

"The radar profile of this area is similar to that of lakes of liquid water found beneath the Antarctic and Greenland ice sheets on Earth, suggesting that there is a subglacial lake at this location on Mars," said the report.

Researchers said they are not sure how far down it goes, but may be around three feet (one meter) deep.

"This is the first body of water it has detected, so it is very exciting," David Stillman, a senior research scientist in the Department of Space Studies at Southwest Research Institute in Texas, told AFP in an email.

However, Stillman, who was not involved in the research, said another spacecraft, or other instruments, need to be able to confirm the discovery.

He noted that a higher-frequency radar instrument made by the Italian space agency, SHARAD, on board the Mars Reconnaissance Orbiter launched in 2005, has been unable to detect subsurface water.

"It is strange that SHARAD cannot confirm this discovery. In fact, SHARAD cannot penetrate through the ice here and no one understands why it can't," Stillman said.

"This suggests that something strange is going on here. Thus, I'm skeptical about this discovery."

But researchers are excited about the potential for future finds, because if liquid water could be found at Mars' south pole, it might be elsewhere too.

"There's nothing special about this location other than the MARSIS radar on the Mars Express spacecraft is most sensitive to that region meaning there are likely similar water deposits below the ground all across Mars," said Duffy.

 

 

 

 

 

Red planet and ‘blood moon’ pair up to dazzle skygazers

 

PARIS - The longest “blood moon” eclipse this century will coincide with Mars’ closest approach in 15 years to offer skygazers a thrilling astronomical double bill on Friday, astronomers say. For about half the world, the moon will be partly or fully in Earth’s shadow from 1714 to 2328 GMT - six hours and 14 minutes in all. The period of complete eclipse - known as “totality”, when the moon appears darkest - will last from 1930 to 2113 GMT. “Totality will last for 103 minutes, making it the longest eclipse of the 21st century!” said the Royal Astronomical Society in London. At the same time, Mars will hover near the moon in the night sky, easily visible with the naked eye. Our neighbouring planet will appear unusually large and bright, a mere 57.7 million kilometres (35.9 million miles) from Earth on its elliptical orbit around the sun. “We have a rare and interesting conjunction of phenomena,” Pascal Descamps, an astronomer with the Paris Observatory, told AFP. “We should have a coppery red tint on the moon with Mars the ‘Red Planet’ just next to it, very bright and with a slight orange hue itself.”

Amateur astronomers in the southern hemisphere will be best-placed to enjoy the spectacle, especially those in southern Africa, Australia, India and Madagascar, though it will also be partly visible in Europe and South America.

A total lunar eclipse happens when Earth takes position in a straight line between the moon and sun, blotting out the direct sunlight that normally makes our satellite glow whitish-yellow.

The moon travels to a similar position every month, but the tilt of its orbit means it normally passes above or below the Earth’s shadow - so most months we have a full moon without an eclipse.

When the three celestial bodies are perfectly lined up, however, the Earth’s atmosphere scatters blue light from the sun while refracting or bending red light onto the moon, usually giving it a rosy blush.

This is what gives the phenomenon the name “blood moon”, though Mark Bailey of the Armagh Observatory in Northern Ireland said the colour can vary greatly. It depends partly on “how cloudy or transparent those parts of the Earth’s atmosphere are which enable sunlight to reach the moon”, he told AFP. “During a very dark eclipse the moon may be almost invisible.

“Less dark eclipses may show the moon as dark grey or brown... as rust-coloured, brick-red, or, if very bright, copper-red or orange.”

The long duration of this eclipse is partly due to the fact that the moon will make a near-central passage through Earth’s umbra - the darkest, most central part of the shadow. Our constant companion will also be at the farthest point on its orbit from Earth, making its movement across the sky slower from our perspective, thus spending longer in the dark.

NASA, meanwhile, has called out social media hoaxers claiming that Mars will appear as big as the moon during the eclipse. “If that were true, we’d be in big trouble given the gravitational pulls on Earth, Mars, and our moon!” the NASA website states.

Mars will more likely appear as a very bright star, and viewers will need no protective eye gear.

“All you have to do is dress warmly and go outside!” the Royal Astronomical Society advises.

“If you want a close-up view of the moon as it turns red, a pair of binoculars is helpful.”

“All eclipses are spectacular,” the society’s Robert Massey added. “In the middle of a lunar eclipse it can look as if a red planet has taken up residence near the Earth - they are both eerie and beautiful and I’ll certainly be looking out for it!”