Ancient lake found on Mars and an important 'puzzle piece' in the hunt for extraterrestrial life

THE BASE of Mars' 45-kilometer-wide Jezero crater is what remains of an ancient lake, scientists have confirmed in a new study.

Sediment collected from the bottom of the ancient lake will act as an important “puzzle piece” in the hunt for extraterrestrial life on the Red Planet, lead study author Dr. David Paige to The Sun.

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Scientists used the Perseverance rover's Radar Imager for Mars' Subsurface Experiment (RIMFAX) to view ancient lake sediment about 65 feet (20 meters) below the surface of the crater floor.

Years of research with ground-penetrating radar and testing RIMFAX on Earth have taught scientists how to 'see' underground layers based on their radar reflections.

Over the centuries, Lake Jezero shrank and sediments carried by the river that fed it formed a huge delta.

Once the sediments in the crater were eroded, the geological features visible on the surface of Mars today were formed.

The lake implies the existence of an ancient 'plumbing' on Mars, according to Dr Paige, who added: 'That's exciting for signs of life.'

The findings are the result of ten years of work.

“The rover has been there since March 2021… but of course the effort to collect the data and build the instrument went back a little further, so realistically a decade in the making,” Dr. Paige said.

The rover, which is about the size of a car and carries seven different scientific instruments, has been exploring the Jezero crater since 2021, studying its geology and atmosphere and collecting samples.

Perseverance's soil and rock samples will be returned to Earth and examined for evidence of past life during a future expedition.

Of all the craters on Mars, why do you choose Jezero?

Mars is covered with thousands of craters, mostly caused by impacts.

But scientists have outlined 205 craters that could have been closed lakes billions of years ago.

Of all the craters on Mars, why did the researchers behind the Perseverance rover choose Jezero?

“We don't know where the real treats will be,” explained Dr. Paige out.

“A whole series of landing sites were taken into account.”

The deciding factors that pushed scientists to Jezero were: technical limitations such as poor terrain, altitude and how close to the equator it is.

Jezero Crater is located just north of Mars' equator, where temperatures are closer to -55ºC than the -153ºC you can experience at the poles.

In 2022, Perseverance drove from the crater floor to the delta, a vast expanse of 3 billion-year-old sediments that, from an orbital perspective, resembles Earth's river deltas.

Scientists also discovered that a second period of deposition occurred when fluctuations in lake levels caused the river to deposit a wide delta that once extended far into the lake.

It has now eroded back closer to the mouth of the river.

“The thing about geology in general is that it's not really linear in time. In other words, we have small windows of opportunity where we have a record that is preserved,” says Dr. Paige.

What makes Mars particularly interesting is that there has been little erosion or tectonic movement in recent history – unlike Earth where much has been obliterated.

“The history is preserved,” Dr. Paige explains, “and is just there for us to look at. It makes it very different from Earth.”

“The main focus of the mission is to return these samples to Earth, which will require many missions.

“This says okay, the samples we can get can be quite interesting.

'They certainly formed in this lake-like environment, where Earth at least has always been teeming with life.

“But your mileage may vary, sometimes you will find fossil and sometimes you won't.

“It's just one piece of the puzzle.”