Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Martian salts must touch ice to make liquid water, study shows

03.07.2014

In chambers that mimic Mars’ conditions, researchers have shown how small amounts of liquid water could form on the planet despite its below-freezing temperatures.

Liquid water is an essential ingredient for life as we know it. Mars is one of the very few places in the solar system where scientists have seen promising signs of it – in gullies down crater rims, in instrument readings, and in Phoenix spacecraft self portraits that appeared to show wet beads on the lander’s leg several years ago.


A Mars Atmospheric Chamber in the Space Research Building at the University of Michigan on June 18, 2014. The chamber simulates the atmospheric conditions of Mars in hopes of producing water through the interaction of salt with the atmospheric conditions simulated by the chamber. The resulting research allows Astrobiologists to postulate about the potential of life on Mars.

Credit: Joseph Xu, Michigan Engineering Communications & Marketing

No one has directly detected liquid water beyond Earth, though. Experiments at the University of Michigan are among the first to test theories about how it could exist in a climate as cold as Mars’.

The researchers found that a type of salt present in Martian soil can readily melt ice it touches – just like salts do on Earth’s slippery winter walkways and roads. But this Martian salt cannot, as some scientists suggested, form liquid water by sucking vapor out of the air through a process called deliquescence.

“For me, the most exciting thing is that I can now understand how the droplets formed on the Phoenix leg,” said Nilton Renno, a professor of atmospheric, oceanic and space sciences at the University of Michigan in Ann Arbor who led the research. The new research is detailed in a paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

In 2008, Renno was the first to notice strange globules in photos Phoenix sent back. Over several weeks, the globules seemed to grow and coalesce. While Renno deemed them water and suggested that salts on the planet’s surface might make it so, many of his colleagues disagreed. Salts had never been found on Mars.

But then they were. Among those that Phoenix detected is calcium perchlorate, a mixture of calcium, chlorine and oxygen that’s found in arid places like the Atacama Desert in Chile. Years later, the Curiosity rover found it elsewhere on Mars. Now scientists believe it and other salts are sprinkled across the planet’s surface.

In the case of Phoenix, Renno believes the craft’s landing thrusters blasted away the topsoil, exposing the ice and melting it. That formed muddy saltwater that splashed on the lander’s leg as it touched down in the northern polar region. The salts allowed the droplets to remain liquid. Their existence and stability, Renno says, tipped scientists off to a cycle that doesn’t need always need help from an Earth-borne spacecraft.

The U-M researchers recreated the Phoenix landing site conditions in their lab in metal cylinders two feet high and five feet long. The late Martian spring/early summer temperatures in the chambers ranged from -121 degrees to -21 degrees Celsius (-185 to -5 Fahrenheit). Atmospheric pressure hovered around 1 percent of Earth’s. Relative humidity varied, but for most experiments, it was set to 100 percent.

They tested two scenarios: perchlorate by itself and perchlorate on top of water ice. In the perchlorate-only experiments, they put millimeter-thick layers of salt on a temperature-controlled plate or Mars-like soil. Even after more than three hours, no liquid water formed. That told them deliquescence wasn’t occurring, and isn’t likely to be a significant process on Mars.

When the researchers placed calcium perchlorate or salty soil directly on a 3-millimeter-thick ice layer, drops of liquid water formed within minutes when the chambers reached -73 degrees C (-100 F). That’s well within the range of conditions observed at the Phoenix landing site.

Researchers didn’t rely on their eyes or cameras to be sure liquid water was there. They used a technique called Raman scattering spectroscopy that involves shining lasers onto the surface and examining the reflected light. Different substances and states of matter have different reflective signatures.

The findings show how small amounts of liquid water could exist across a large swath of Mars’ surface and shallow subsurface, from its polar regions to its mid-latitudes, for several hours a day during the spring and early summer. Such a cycle could form gullies, Renno says, flowing, freezing, thawing and flowing again. Water could also form just beneath the surface.

Renno says the water wouldn’t necessarily need to stay liquid indefinitely for it to support microbial life now or have supported it in the past. Antarctic saltwater and lattices of brine-filled ice-combs have been found to harbor microbial organisms on Earth.

“Mars is the planet in our solar system that is most similar to Earth. Studies suggest that Mars used to be even more Earth-like in the past, with flowing water on the surface. By studying the formation of liquid water on Mars we can learn about possibilities of life outside Earth and look for resources for future missions,” said Erik Fischer, doctoral student in the Department of Atmospheric, Oceanic and Space Sciences (AOSS) at the University of Michigan and first author of the new paper.

The research is supported by NASA’s Exobiology Program. In addition to Renno and Fischer, other authors are Harvey Elliott, doctoral student in AOSS and Germán M. Martínez, research scientist at AOSS.

For additional images, visit https://www.flickr.com/photos/michigan-engineering/sets/72157645284722303/

For more information, visit “Revisiting Mars: The search for liquid water and life on the planet next door”: http://www.engin.umich.edu/college/about/news/stories/2011/june/revisiting-mars-the-search-for-liquid-water-and-life-on-the-planet-next-door

Notes for Journalists

Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this accepted article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2014GL060302/abstract

Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at nbompey@agu.org. Please provide your name, the name of your publication, and your phone number.

Neither the paper nor this press release is under embargo.

Title

“Experimental evidence for the formation of liquid saline water on Mars”

Authors:
Erik Fischer, Germán M. Martínez, Harvey M. Elliott and Nilton O. Rennó: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan, USA.

Contact information for the authors:
Erik Fischer: +1 (734) 647-9441, erikfis@umich.edu

AGU Contact:

Nanci Bompey
+1 (202) 777-7524
nbompey@agu.org

University of Michigan Contact:
Nicole Casal Moore
+1 (734) 647-7087
ncmoore@umich.edu

Nanci Bompey | American Geophysical Union
Further information:
http://news.agu.org/press-release/martian-salts-must-touch-ice-to-make-liquid-water-study-shows/

Further reports about: Atmospheric Earth Geophysical Mars Martian deliquescence perchlorate salts spacecraft

More articles from Earth Sciences:

nachricht Past and present sea levels in the Chesapeake Bay Region, USA
29.07.2015 | Geological Society of America

nachricht “Carbon sink” detected underneath world’s deserts
29.07.2015 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>