. 24/7 Space News .
EXO WORLDS
The search for life beyond Earth
By Manel MENGUELTI
Paris (AFP) Feb 18, 2021

Mars may now be considered a barren, icy desert but did Earth's nearest neighbour once harbour life?

It is a question that has preoccupied scientists for centuries and fired up sci-fi imaginings.

After seven months in space, NASA's Perseverance rover is due to land on Mars on Thursday, in search of clues.

- Why Mars? -

Other planets or moons, could also harbour forms of life, so why pick Mars?

NASA says Mars is not just one of the more accessible places in the solar system and a potential future destination for humans, but exploring the planet could also help to answer "origin and evolution of life questions".

"Mars is unique across the entire solar system in that it is a terrestrial planet with an atmosphere and climate, its geology is known to be very diverse and complex (like Earth), and it appears that the climate of Mars has changed over its history (like Earth)," it adds on its Mars programme website.

Scientists believe that four billion years ago the two planets both had the potential to nurture life -- but much of Mars' intervening history is an enigma.

Mars exploration is not to find Martian life -- scientists believe nothing would survive there now -- but to search for possible traces of past lifeforms.

Perseverance is tasked with searching for telltale signs that microbial life may have lived on Mars billions of years ago.

- Ingredients for life -

For life you need water.

A planet in what is known as the "habitable zone" around a star is an area in which water has the potential to be liquid.

If it is too close to the star the water would evaporate, too far away it would freeze (some call this the "Goldilocks principle").

But water alone is not enough.

Scientists also look for the essential chemical ingredients, including carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur.

And to stir it all up, they also look for a source of energy, said Michel Viso, an astrobiologist at CNES, the French space agency.

This could come from the Sun, if the planet is close enough, or from chemical reactions.

- Martian fascination -

Scientific enquiry of the red planet began in earnest in the 17th Century.

In 1609 Italian Galileo Galilei observed Mars with a primitive telescope and in doing so became the first person to use the new technology for astronomical purposes.

Mars -- compared to the "desolate, empty" moon -- has long seemed promising for potential inhabitability by microorganisms, wrote astrophysicist Francis Rocard in his recent essay "Latest News from Mars".

But the 20th century presented setbacks.

In the 1960s, as the race to put a man on the moon was accelerating, Dian Hitchcock and James Lovelock analysed the atmosphere on Mars looking for a chemical imbalance, gases reacting with each other, which would hint at life.

There was no reaction.

A decade later the Viking landers took atmospheric and soil samples that showed the planet was no longer inhabitable and interest in Mars crumbled.

But in 2000 scientists made a game-changing discovery: they found that water had once flowed over its surface.

This rekindled interest in Mars exploration and scientists pored over images of gullies, ravines, scouring the Martian surface for evidence of liquid water.

More than 10 years later, in 2011, they definitively found it.

Scientists now think Mars may once have been warm and wet and possibly have supported microbial life.

"As the Sun did not always have the same mass, the same energy, Mars could very well have been also in this habitable zone early in its existence," said astrophysicist Athena Coustenis, of the Paris-PSL Observatory.

If life did exist on Mars, why did it disappear?

And perhaps more profoundly if life never existed, then why not?

- Further frontiers -

There are always other areas to explore.

Jupiter's moon Europa, spotted by Galileo four centuries ago, may have a saltwater ocean hidden beneath its icy surface that is thought to contain about twice as much water as Earth's global ocean.

NASA says it "may be the most promising place in our solar system to find present-day environments suitable for some form of life beyond Earth".

Its tidal energy might also cause chemical reactions between water and rock on the seafloor, creating energy.

Future missions include NASA's upcoming Europa Clipper and the European probe JUICE.

Saturn's frozen ocean moon Enceladus is also considered a promising contender.

The American Cassini probe, orbiting the planet from 2004 to 2017, discovered the existence of water vapour geysers on Enceladus.

In 2005, NASA's Cassini spacecraft discovered geysers of icy water particles and gas gushing from the moon's surface at approximately 800 miles (1,290 kilometers)per hour.

The eruptions generate fine ice dust around Enceladus, which supplies material to Saturn's ring.

No mission is currently scheduled to Enceladus.

Another of Saturn's moons Titan -- the only moon in the solar system known to have a substantial atmosphere -- is also of interest.

The Cassini mission found it has clouds, rain, rivers, lakes and seas, but of liquid hydrocarbons like methane and ethane.

NASA, whose Dragonfly mission will launch in 2026 and arrive in 2034, says Titan could be lifeless or harbour "life as we don't yet know it".


Related Links
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


EXO WORLDS
A new way to look for life-sustaining planets
Tucson AZ (SPX) Feb 11, 2021
It is now possible to capture images of planets that could potentially sustain life around nearby stars, thanks to advances reported by an international team of astronomers in the journal Nature Communications. Using a newly developed system for mid-infrared exoplanet imaging, in combination with a very long observation time, the study's authors say they can now use ground-based telescopes to directly capture images of planets about three times the size of Earth within the habitable zones of nearb ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

EXO WORLDS
Who Controls Space

Astronauts training for space station missions

Space for all is this student's goal

NASA fears gap in astronaut crew at multibillion-dollar space station

EXO WORLDS
Russia plans at least 10 launches from Baikonur in 2021

DLR ready to test first upper stage for Ariane 6

Kremlin 'interested' in Elon Musk-Putin conversation

Space Nuclear Propulsion Technologies central to future of Mars Exploration

EXO WORLDS
Airbus space technology reaches Mars

Mars rover mission could drive research for decades to come

Tuning in for a precision landing on Mars on Feb 18

Skoltech's recent achievement takes us one step closer to Mars

EXO WORLDS
Chinese tracking vessel sets sail for monitoring missions in Indian Ocean

China's 'space dream': A Long March to the Moon and beyond

Three generations dedicated to space program

China's space station core module, cargo craft pass factory review

EXO WORLDS
RUAG Space positions itself for the future

First Airbus Eurostar Neo satellite is born

Axiom Space raises $130M in Series B funding

SpaceX launches Starlink satellites, loses booster in sea

EXO WORLDS
Falling to Earth takes a long time

Northrop Grumman's SharkSat Payload Showcases Agility from the Ground to Orbit

Arch Mission Foundation announces first in series of Earth Archives

Purdue to co-lead DoD-funded project to advance adoption of lead-free electronics

EXO WORLDS
On the quest for other Earths

NASA's TESS discovers new worlds in a river of young stars

Lasers reveal the secret interior of rocky exoplanets

A new way of forming planets

EXO WORLDS
Solar system's most distant planetoid confirmed

Peering at the Surface of a Nearby Moon

A Hot Spot on Jupiter

The 15th Anniversary of New Horizons Leaving Earth









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.