Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Phoenix Mars Lander Finds Surprises About Planet’s Watery Past

An instrument designed and built at the UA measured the isotopic composition of the Mars atmosphere, suggesting liquid water has interacted with the Martian surface throughout the planet's history.

Liquid water has interacted with the Martian surface throughout Mars' history, measurements by NASA's Phoenix Mars Lander suggest.

The findings, published in the Sept. 10 issue of the journal Science, also suggest that liquid water has primarily existed at temperatures near freezing, implying hydrothermal systems similar to Yellowstone's hot springs on Earth have been rare on Mars throughout its history.

These surprising results come from measurements Phoenix made in 2008 of stable isotopes of carbon and oxygen in the carbon dioxide of the Martian atmosphere. Isotopes are variants of the same element with a different number of neutrons, such as carbon-12, with six neutrons, and the rarer carbon-13, with seven.

Unprecedented precision in determining the ratios of isotopes in Martian carbon dioxide sheds new light on the history of water and volcanic activity on the surface of Mars.

The measurements were performed by the Evolved Gas Analyzer on Phoenix, part of the lander's Thermal and Evolved Gas Analyzer, or TEGA, an instrument designed and built at the University of Arizona. TEGA's mass spectrometer was capable of a more accurate analysis of carbon dioxide than the ones on NASA's Viking landers in the 1970s, the only other such instruments that have returned results on isotopic composition from Mars.

"We use the TEGA instrument as a crime scene investigator," said William V. Boynton, a professor at the Lunar and Planetary Lab in the UA's department of planetary sciences. "Like a chemical fingerprint, isotopes tell us what process is responsible for making the material we are studying." Boynton, who heads the group that built the TEGA instrument, co-authored the Science paper.

Carbon dioxide makes up about 95 percent of the Martian atmosphere. NASA's Mars Exploration Program has put a high priority on learning more about the isotope ratios in Martian carbon dioxide to supplement the information from Viking and from analysis of meteorites that have reached Earth from Mars.

For the measurement, the TEGA instrument on the lander opened a pin-point-sized hole while a vacuum sucked a puff of Martian atmosphere into its chamber for isotope analysis.

The analysis revealed that carbon dioxide on Mars has proportions of carbon and oxygen isotopes similar to carbon dioxide in Earth's atmosphere. This unexpected result reveals that Mars is a much more geologically active planet than previously thought. In fact, the new results suggest that Mars has replenished its atmospheric carbon dioxide relatively recently, and that the carbon dioxide has reacted with liquid water present on the surface.

"Atmospheric carbon dioxide is like a chemical spy," said Paul Niles, a space scientist at NASA's Johnson Space Center in Houston and lead author of the paper. "It infiltrates every part of the surface of Mars and can indicate the presence of water and its history."

The low gravity and lack of a magnetic field on Mars mean that as carbon dioxide resides in the atmosphere it will be lost to space, a process that favors loss of the lighter carbon-12 isotope compared to carbon-13. Although an older atmosphere on Mars should contain much more carbon-13, it doesn't. This suggests that the Martian atmosphere has been recently replenished with carbon dioxide emitted from volcanoes, and volcanism has been an active process in Mars' geologically recent past.

Another clue comes from the second element that makes up carbon dioxide: oxygen. Oxygen, like carbon, comes in different isotopes: oxygen-16 and the heavier oxygen-18.

The team compared the results from Phoenix to measurements obtained from Martian meteorites that were hurled into space from the Red Planet's surface during impact events and eventually fell onto Earth where they were later collected. The meteorites contain carbonate minerals that form only in the presence of liquid water and carbon dioxide.

"Carbon dioxide spewed into the atmosphere by volcanoes is very similar in its oxygen isotope ratio to that found in rocks," said Boynton. "But we see a big difference between the oxygen ratios of the volcanic rocks and the atmosphere."

This suggests that the carbon dioxide in the volcanic rock of Martian meteorites has reacted with liquid water, enriching the oxygen in carbon dioxide with heavier oxygen-18.

The comparisons of isotopes in Mars' atmosphere with those in the meteorites provide confirmation of key findings. For example, one meteorite that crystallized during recent geological time on Mars – about 170 million years ago rather than billions of years ago – has carbonates with isotopic proportions that match the atmospheric measurements by Phoenix.

According to Niles, the isotopic signature indicates that liquid water has been present on the Martian surface recently and abundantly enough to affect the composition of the current atmosphere. It also reveals the water has primarily existed at temperatures near its freezing point.

The results provide supporting evidence that the watery conditions associated with carbonate formation have continued even under Mars' current cold and dry conditions.

"This shows that the carbonates formed under the influence of water and the atmosphere in the recent geologic past," Boynton said.

Niles added: "The findings do not reveal specific locations or dates of liquid water and volcanic vents, but geologically recent occurrences of those conditions provide the best explanations for the isotope proportions we found."

The University of Arizona conceived of and ran the Phoenix mission, which landed near the north pole of Mars in May of 2008; it is the first Mars mission ever led by a university. The Principal Investigator is Peter H. Smith, a professor at the UA's Lunar and Planetary Lab. NASA's Jet Propulsion Laboratory in Pasadena, Calif., provided the management of the project. For his leadership on the TEGA project, Boynton was recently honored with NASA's Exceptional Public Service Medal.


William V. Boynton,
Lunar and Planetary Laboratory,
The University of Arizona,
(520) 621-6941;
Daniel Stolte,
University of Arizona Office of Communications,
520) 626-4402;

William V. Boynton | University of Arizona
Further information:

More articles from Physics and Astronomy:

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>