NewsBite

‘Red planet apocalypse’: Was life on Mars wiped out by global warming?

SCIENTISTS believe Mars was covered in ice roughly 3.8 billion years ago but it was melted by climate change, wiping out potential life.

Did a warming event kill life on Mars? Picture: NASA/JPL-Caltech
Did a warming event kill life on Mars? Picture: NASA/JPL-Caltech

GLOBAL warming that scorched the surface of Mars for up to 10 million years may have wiped out life on the Red Planet, it is claimed.

It is thought Mars was frozen over roughly 3.8 billion years ago before warming periods melted the surface and created deep valleys and canyons, The Sun reports. Scientists believe this could by why the planet has water-carved features.

Water provides the conditions needed for life — so there could have been living organisms on Mars billions of years ago.

However, if there was they may well have been wiped out by the changing climate.

A build-up of greenhouse gases in Mars’ dense atmosphere is thought to have sparked dramatic climate cycles.

Some studies have suggested the warming of Red Planet was brought on by asteroid impacts, but many researchers believe warming cycles are responsible.

Natasha Batalha, a graduate student of astronomy and astrophysics, said: “With the cycling hypothesis, you get these long periods of warmth that give you sufficient time to form all the different Martian valley networks.”

The valleys on Mars are similar in width to the Grand Canyon — which is thought to have been carved out 16 million years ago when they Colorado River swelled after melting.

Planet Mars, close-ups, part of the Melas Chasma, a vast canyon, exposes layered deposits that could be sediment from an old lake or windblown volcanic ash and sediment deposits on the planet.
Planet Mars, close-ups, part of the Melas Chasma, a vast canyon, exposes layered deposits that could be sediment from an old lake or windblown volcanic ash and sediment deposits on the planet.

This type of climate model demonstrates how warming periods caused by greenhouse gases persisted for millions of years, researchers claim.

Jim Kasting, from Department of Astronomy and Astrophysics, said: “We think Mars had to be warm for millions to tens of millions of years, and the impact hypothesis can keep it warm for thousands of years.

“In terms of water, we need millions of metres of rainfall, and they (previous studies) can get hundreds of metres”.

Ms Batalha added: “Mars is in this precarious position where it’s at the outer edge of the habitable zone.

“It’s receiving less solar flux, so you start at a glaciated state.

“There is volcanic out-gassing, but because you are colder, you don’t get the same deposition of carbon back into the planet’s surface.

“Instead, you get this atmospheric build-up and your planet slowly stars to rise in temperature.”

Researcher are still trying to work out if Mars could have produced enough carbon dioxide and hydrogen for this process to work.

Mr Kasting said: “We would be well off if early Mars had plate tectonics just like Earth has today.

“Then it works. But that’s a big debate.

“A lot of people don’t think Mars ever had it.”

This article originally appeared in The Sun.

Mars may have been host to plenty of life in the distant past.                         Man on Mars - Mission to the Red Planet
Mars may have been host to plenty of life in the distant past. Man on Mars - Mission to the Red Planet

Original URL: https://www.news.com.au/technology/science/space/red-planet-apocalypse-was-life-on-mars-wiped-out-by-global-warming/news-story/8b257d68ea212f72b1b62f18d88c3e4a