. 24/7 Space News .
EXO WORLDS
Earth's stable temperature past suggests other planets could also sustain life
by Staff Writers
Seattle WA (SPX) Apr 03, 2018

illustration only

Theories about the early days of our planet's history vary wildly. Some studies have painted the picture of a snowball Earth, when much of its surface was frozen. Other theories have included periods that would be inhospitably hot for most current lifeforms to survive.

New research from the University of Washington suggests a milder youth for our planet. An analysis of temperature through early Earth's history, published the week of April 2 in the Proceedings of the National Academy of Sciences, supports more moderate average temperatures throughout the billions of years when life slowly emerged on Earth.

"Ideas about the early Earth's environment are all over the place, from a very hot world, to one locked in a permanent ice age, from a world with acidic oceans to one with seawater so alkaline it would sting your eyes," said David Catling, a UW professor of Earth and space sciences. "These simulations show that our early world had about the same average temperature as today, and a seawater pH within roughly one unit of neutral."

Previous research studies have put average temperatures during the Archean era, 4 to 2.5 billion years ago, as low as minus 25 degrees Celsius. Other estimates, based on different interpretations of the evidence, have placed average temperatures as high as 85 degrees Celsius, under which only heat-loving microbes that now exist in hot springs could survive.

The new results put the outer range of possible temperatures at 0 to 50 C (32 to 122 F).

"Our results show that Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks - they do a good job at maintaining a habitable climate," said first author Joshua Krissansen-Totton, a UW doctoral student in Earth and space sciences.

To create their estimate, the researchers took the most recent understanding for how rocks, oceans, and air temperature interact, and put that into a computer simulation of Earth's temperature over the past 4 billion years. Their calculations included the most recent information for how seafloor weathering occurs on geologic timescales, and under different conditions.

Though we don't think of wind and rain wearing away at the seafloor, the seabed is eroded as seawater percolates through rock on the ocean's floor. Carbon-containing molecules settle out from the water, a process related to the temperature and acidity of the seawater, while other chemicals are dissolved from the rock.

"Seafloor weathering was more important for regulating temperature of the early Earth because there was less continental landmass at that time, the Earth's interior was even hotter, and the seafloor crust was spreading faster, so that was providing more crust to be weathered," Krissansen-Totton said.

The authors ran simulations for many possible scenarios for the size of the continents, the temperature sensitivity of chemical weathering and other factors to get the full range of possible scenarios for average air temperature and ocean pH through history.

"We got this initial answer that early Earth had moderate temperatures and slightly acidic ocean pH," Krissansen-Totton said. "I tried really hard to break that, looking for assumptions that could possibly change that answer. But I found that this is a really robust result. It's hard to imagine a realistic scenario where temperatures or pH were more extreme."

That is good news for the search for life on other planets. If Earth's temperature was pretty moderate throughout its history, other planets located in the habitable zone must also retain a fairly stable climate long enough for other lifeforms to evolve.

"There's nothing particularly remarkable about these processes," Krissansen-Totton said.

"They can occur on any rocky planet with oceans. So other planets that are in the habitable zone are likely to have their climates stabilized to moderate values by these weathering feedbacks. And that's a good thing for the search for life, because you need moderate temperatures for billions of years to have a stable environment for life to evolve."

The results may also help shed light on what conditions were like during the early evolution of life on Earth.

"The results help us understand how natural processes kept Earth's environment suitable for life to carry on for billions of years, from its humblest beginnings to the wonderful forms now around us," Catling said.


Related Links
University of Washington
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
Is there life adrift in the clouds of Venus?
Madison WI (SPX) Apr 03, 2018
In the search for extraterrestrial life, scientists have turned over all sorts of rocks. Mars, for example, has geological features that suggest it once had - and still has - subsurface liquid water, an almost sure prerequisite for life. Scientists have also eyed Saturn's moons Titan and Enceladus as well as Jupiter's moons Europa, Ganymede and Callisto as possible havens for life in the oceans under their icy crusts. Now, however, scientists are dusting off an old idea that promises a new v ... 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
NASA accepting applications for mission control leaders

Out of this world: Inside Japan's space colony centre

Aerospace Tech Startups Get a Chance to Pitch at JPL

US astronauts make spacewalk to perform ISS repairs

EXO WORLDS
University student projects launch from NASA Wallops

SpaceX launches cargo to space station using recycled rocket, spaceship

New research payloads heading to ISS on SpaceX Resupply Mission

Funds shortage pulls the brakes on India's crucial space programs

EXO WORLDS
Opportunity making extensive study of rock target Aguas Calientes

Curiosity rover gets ready for its next adventure

First test success for largest Mars mission parachute

Opportunity Completes In-Situ Work on 'Aguas Calientes'

EXO WORLDS
Earth-bound Chinese spacelab plunging to fiery end

China's 'space dream': A Long March to the moon

China says Earth-bound space lab to offer 'splendid' show

Tiangong-1 expected to burn up on reentering atmosphere

EXO WORLDS
Relativity Space raises 35M in Series B funding

Storm hunter launched to International Space Station

SSL to build direct broadcasting satellite for B-SAT

SpaceX says Iridium satellite payload deployed

EXO WORLDS
The Problem With Space Junk is We Don't Know Where Most Objects Are

Finding order in disorder demonstrates a new state of matter

Mars mission: how increasing levels of space radiation may halt human visitors

Point Nemo, Earth's watery graveyard for spacecraft

EXO WORLDS
NASA prepares to launch next ExoPlanet mission

Is there life adrift in the clouds of Venus?

Characterization of a water world in a multi-exoplanetary system

Hot, metallic Mercury-like exoplanet discovered 340 light-years from Earth

EXO WORLDS
Jupiter's turmoil more than skin deep: researchers

New Horizons Chooses Nickname for 'Ultimate' Flyby Target

Jupiter's Great Red Spot getting taller as it shrinks

Jupiter's Jet-Streams Are Unearthly









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.