At last! Scientists find 12-mile lake on Mars

Wavy: An artist’s depiction of Marsis discovering the lake, featuring radar readings above.

Is there life on Mars? After decades of study, a body of liquid water has finally been detected on the Red Planet. The discovery raises exciting possibilities for our search for alien life.

For decades, scientists seeking signs of life elsewhere in the universe had one mantra: “Follow the water.” In the end they did not have to look far. After years of observation, Italian researchers have detected a vast lake of liquid water on Mars, locked a mile under the planet’s icy south pole.

Using a system called Marsis, they beamed radio waves at the surface of Mars and observed what bounced back, finding a subterranean body more reflective than the ice above.

They tested “every possible alternative”, but at last confirmed the only remaining explanation: a lake of water.

The discovery raises a thrilling possibility that has captured the human imagination for centuries. Could the Red Planet host life?

Encouragingly, the lake resembles bodies of water below glaciers on Earth, where we often find bacterial life. “Pretty much anywhere there is liquid water on Earth, you find something that’s managed to survive in it,” says scientist Tanya Harrison.

Another good sign is the methane gas detected by rovers and orbiters. On Earth, most methane comes from microbial life.

But there is cause for scepticism. The lake remains liquid despite being tens of degrees below freezing, possibly due to high levels of dissolved salts. If the substance is a salty brine, experts say it could be “pretty challenging” for anything to survive.

Should the latest discovery end in disappointment, it will not be our first false alarm. American astronomer Percival Lowell provoked hysteria in 1906 when he concluded that a Martian race had dug a complex network of canals to access water from the ice caps and distribute it across Mars.

He may have been wrong, but Lowell created a boom in interest that would inspire science fiction for decades.

More recently, NASA’s claim in 1996 to have found microbial fossils from Mars was retracted after further study, while small flows of water observed in 2015 may in fact have been dust and sand. The scientists might seem sure now, but further observation of this “lake” could end in another walk-back.

Do you think there is life on Mars?

Little green men

Almost certainly not, say some. We can’t confirm that this “lake” contains water yet, so it’s far too early to speculate on alien life. Mars may once have been watery and warm but now it’s a dead planet blasted with radiation. Each time we get our hopes up, science advances and we are once more disappointed.

We should be optimistic, others argue. Water is the key to life and finding it on a neighbouring planet is perhaps the biggest leap yet in our search. Even if nothing survives on Mars now, it probably did in the distant past and this bolsters our hopes of finding alien life further from home. We’re not alone.

You Decide

  1. Is there life on Mars?
  2. How would you feel if alien life was discovered? Excited or scared?

Activities

  1. Research the different atmospheres and surfaces of our solar system’s eight planets. Draw and label a diagram of the solar system with your findings.
  2. Imagine Mars in the distant past, with oceans and possibly life. Write a short story about an inhabitant of Mars, being as creative and fantastical as you can.

Some People Say...

“Either we are alone in the Universe or we are not. Both are equally terrifying.”

Arthur C. Clarke

What do you think?

Q & A

What do we know?
The 12-mile-wide body of water was discovered by the European Space Agency using a radar instrument called Marsis. It has been taking readings from Mars’s orbit since 2012. Looking at the picture above, the top of the image shows the radar images taken by Marsis. The top white line represents the planet’s icy shell, while the stronger, blue markings beneath show where the underground lake is.
What do we not know?
Whether this discovery will do much to advance the search for life on Mars. Dr Manish Patel has said we are “not closer to actually detecting life” but we have a better idea of where to look — it is like having an X on a treasure map. We may not be able to explore the lake for a long time due to the icy surface above.

Word Watch

Marsis
The name stands for Mars Advanced Radar for Subsurface and Ionosphere Sounding.
Subterranean
Underneath a planet’s surface; underground.
Bacterial life
Life began on Earth around four million years ago with single-cell organism. For the next three billion years, microscopic bacteria was the main form of life. We think that life on Mars would probably take this form.
Rovers and orbiters
There have been four successful Mars rovers that have looked for evidence on the planet’s surface, and 14 scientific instruments that have orbited the planet.
Salts
Scientists think that salt, magnesium and calcium in the lake may have lowered its freezing temperature.
Science fiction
H. G. Wells’s War of the Worlds was influenced by Lowell’s research through the late 19th and early 20th century. In it, a dying Martian race attempts to invade Earth to survive.
Past
Many scientists believe much of Mars was once covered by oceans. As the planet’s atmosphere cooled, most of its water became locked up as ice.

Subjects

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