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The combination of the SAM pyrolysis and gas chromatograph mass spectrometer (GCMS) systems led to the first detection and identification of organic molecules indigenous to a martian sample. At the Cumberland drill hole in the Yellowknife Bay formation, SAM scientists reported the discovery of chlorobenzene (a six carbon ring with a chlorine atom) and chlorinated two to four-carbon chains (dichloroalkanes). These organic molecules are thought to be products of reaction between perchlorates or other oxychlorine salts and more complex organic material preserved in surface rocks over geological timescales. The origin of the organic material remains unknown and may be exogenous (from meteorites or interplanetary dust particles), or internal to Mars from hydrothermal activity or even biological activity. This detection opens up the habitability of Gale Crater to another level where the building blocks of life were present on the red planet at the time liquid water was flowing and at the time life appeared on the Earth. These measurements represent the first detection on Mars of indigenous organic compounds in surface rocks and addressed a long standing objective of the Mars exploration program.

Graph showing chlorobenzene amounts in 4 locations on Mars.

The Freissinet et al. ": Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars" paper which made the cover of the Journal of Geophysical Research: Planets journal is available in open access here: http://onlinelibrary.wiley.com/doi/10.1002/2014JE004737/full.

Author: Caroline Freissinet

NASA recently unveiled two new online tools that allow users to participate in the journey to Mars. Mars Trek is a free, Web-based application that provides high-quality, detailed visualizations of the planet using real data from 50 years of NASA exploration and allowing astronomers, citizen scientists and students to study the Red Planet's features. Experience Curiosity allows viewers to journey along with the rover, including the SAM instrument suite, on its expedition within Gale Crater. The program simulates Mars in 3-D based on actual data from Curiosity and NASA's Mars Reconnaissance Orbiter (MRO), giving users first-hand experience in a day in the life of a Mars rover. More details are available in this NASA press release.

Author: Lora Bleacher

In celebration of Curiosity’s 3rd anniversary of a successful landing on Mars, a Chilean journalist interviewed team members, including Ashwin Vasavada, Curiosity’s Project Scientist, and SAM’s Principal Investigator, Paul Mahaffy, to discuss the mission’s achievements and the challenges that still lie ahead. You can read about it here – in Spanish!

English updates are also available: You can watch a video, download a poster, send a postcard, and see top science discoveries on the Curiosity website, created in honor of this occasion.

Author: Andrea Jones

While we are studying everything we can about the rocks on the surface of Mars, SAM is busy making sure we also learn as much as we can about the atmosphere of Mars!

The inert gases are special because they don’t react with other chemical elements the way some other familiar elements like carbon, oxygen, sulfur, sodium, hydrogen, and silicon, do. That’s why the inert gases are also called noble. These noble gases are helium, neon, argon, krypton, xenon, and radon.

The noble gases are released from the interiors of planets. Over time, some of the gases inside planets escape into the atmosphere, and some of the atmospheric gases escape into space.

The noble gases have stable isotopes (varieties of the same element but with a different number of neutrons in their nuclei), which are useful in tracking evidence of processes that have affected planets over time. Scientists measure the amount of each stable isotope present in a planet’s atmosphere for a number of noble gases, and compare the ratios of these isotopes to each other and to values typical of the solar wind, primitive meteorites, meteorite samples from planets like Mars, and the atmospheres of Earth and Mars. The ratios of noble gas stable isotopes are different in each of these different environments which tells us something about where they came from and some of the processes that have affected them over time.

The noble gases krypton and xenon have lots of isotopes—krypton has six and xenon has nine! They are really big atoms, so they don’t get included in the formation of minerals and they are not very mobile. And now SAM has measured all the stable isotopes of these trace species in the atmosphere of Mars! This is important because it is the most precise measurement ever made of these gases directly in the martian atmosphere. It required a technological feat that has not previously been done on another planet.

Usually, gases flow directly through SAM’s measurement chamber and we measure them as they move. But in a special experiment called static mass spectrometry, SAM was able to hold gases inside its measurement chamber, accumulating enough gas pressure that there were sufficient atoms of the noble gas stable isotopes to count them before the gases were released.

What do these krypton and xenon measurements tell us? They help us better understand the evolution of the Mars atmosphere. Even though Mars has roughly the same total amount of xenon in its atmosphere as Earth does, for example, the ratios of the xenon isotopes in Mars’s atmosphere are different than the xenon isotope ratios in Earth’s atmosphere. The xenon and krypton isotope ratio measurements help us to infer is that Mars lost most of its original atmosphere pretty early in its evolution – a very important discovery.

Three years on Mars, breathing in and breathing out, and SAM is still learning new things about the martian atmosphere.

Author: Pan Conrad

Astrobiology Magazine made a list of the Top 10 astrobiology stories of 2014. Three of the ten stories featured results from the Mars Science Laboratory Curiosity rover, and their number one story of the year is the first definitive discovery of organic molecules on the surface of Mars: a discovery made by the SAM team using data from their powerful instrument suite.

The full article, with links to publications and video footage describing the discovery, is available here: http://www.astrobio.net/news-exclusive/48291/

Author: Andrea Jones

SAM results were highlighted in a press conference held today at the American Geophysical Union Fall Meeting in San Francisco, California. SAM detected a sharp increase and then decrease in the amount of methane (an organic chemical) in the atmosphere surrounding the Curiosity rover, and also detected different martian organic chemicals in powder drilled from a rock in Gale Crater - the first definitive detection of organics on the surface of Mars.

The press release is available here: http://www.jpl.nasa.gov/news/news.php?feature=4413

The Webster et al. and Mahaffy et al. Science Express papers, which describe these results in more detail, are accessible here: http://mars.jpl.nasa.gov/msl/mission/science/researchpapers/

Author: Andrea Jones

SAM and SAM scientist Danny Glavin are featured in the New York Times science article Mars Rover Finds Stronger Potential for Life by Marc Kaufman. The article includes a fantastic interactive that highlights Curiositys's activities and the path it's traveled since it touched down on Mars.

Read about it at: http://www.nytimes.com/2014/12/09/science/-stronger-signs-of-life-on-mars.html?_r=0

Author: Andrea Jones

This mosaic, taken with the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter, shows the planned route (in yellow) of NASA's Curiosity rover from "Pahrump Hills" at the base of Mount Sharp, through the "Murray Formation," and south to the hematite ridge further up the flank of Mount Sharp. Go here for more information about the image. Image Credit: NASA/JPL-Caltech

Three weeks ago, Curiosity fulfilled one of the mission's long-term goals when she arrived at Pahrump Hills, the base of Mount Sharp in Gale Crater. The suite of minerals in the three kilometer high mountain, first identified by satellites in orbit around Mars, told us that something every interesting happened in Gale Crater a long time ago.

Three distinct sets of rock units became clear from orbit: the first appears to be composed of clay-bearing rocks, the second forms a resistant hematite-bearing ridge, and the third contains sulfate-bearing rocks. Clay-bearing units, such as this one, suggest the presence of a lot of water at one time on Mars, while the sulfate-rich rocks suggest a time of "drying-out". This interesting suite of rock units may record a significant climatic change on Mars, from the time Mars was wet to the arid environments we're familiar with today - and Curiosity is starting to learn about it from the ground up!

Curiosity drove though sandy, interconnected valleys to arrive at Pahrump Hills. Her view from the ground is providing us with more information about the rocks we first saw from orbit. The rocks exposed at the very bottom of Mount Sharp are called the Murray Formation. The Pahrump Hills site (found at the edge of where the Murray Formation is exposed at the surface) includes a very soft rock unit, believed to be a fine-grained rock like a mudstone. It has morphologically interesting features in the shallow subsurface that form dendrites and clusters. These features were likely formed by fluids that moved through the Martian mudstone a long time ago. The science team hopes to learn about the composition of these fluids and the surrounding rock by analyzing samples of the rocks with the rover's internal instruments, CheMin and SAM. Curiosity drilled 6.7 centimeters into the soft rock of Pahrump Hills, and the next step is to ensure the drill powder is safe to deliver to the internal instruments. Once this is confirmed, the SAM team will get our first taste of Mount Sharp rocks!

Curiosity completed its primary mission after one Mars year (two Earth years) of surface operations. It has now begun its extended mission. SAM will continue to play a vital role in this second phase of Curiosity's mission, providing chemical and isotopic analyses that help the rover's science team understand what's in the clay-, sulfate-, and hematite-bearing rock units, how they formed in Mount Sharp, and what those rocks can tell us about the ancient environments and climatic evolution of Gale Crater - and Mars. Like a good field geologist, we're starting from the ground up at Pahrump Hills!

To see Curiosity's route from landing to Pahrump Hills, go here.

Author: Amy Williams

Paul Mahaffy is the 2014 winner of the John C. Lindsay Memorial Award, a highly prestigious award for scientists at NASA's Goddard Space Flight Center. Dr. Mahaffy will deliver the John C. Lindsay Memorial Lecture, "Chlorinated Organics in a Gale Crater Mudstone and the Imprint of an Ancient Fluvial Environment in 3 Billion Year Old Water Found in a 4 Billion Year Old Martian Rock," as part of Goddard's colloquium series on Wednesday, October 1 at 3:30pm.

The abstract is available here: http://scicolloq.gsfc.nasa.gov/Mahaffy_Lindsay.html

Information about attending or streaming the presentation is available here: http://scicolloq.gsfc.nasa.gov.

Author: Andrea Jones

The SAM team recently made a shiny, new updated fact sheet. Find an overview of SAM and how it analyzes rock, soil, and atmospheric samples with its three powerful instruments here!

Author: Andrea Jones

Check it out! A video featuring MarsFest in Death Valley National Park. The SAM Team will support the third annual MarsFest at the end of this week!


Author: Andrea Jones

Planetary scientists have long studied terrestrial analogs to help them better understand the environments they observe or expect to encounter on other bodies in the Solar System. Death Valley National Park encompasses some of the most extreme environments on Earth, some of which share many similarities with Martian environments. For decades, planetary scientists and engineers have visited the Park to conduct research and test instruments.

MarsFest is a festival that invites the public to celebrate this scientific heritage and the connections between Death Valley and planetary science and exploration. It is a collaborative effort between NASA, the National Park Service, and the SETI Institute. The SAM E/PO Team helps organize and run the festival. This year, I will give a talk about the importance of planetary analog sites, as well as an overview of the Curiosity mission and science highlights so far (particularly featuring SAM) during a Curiosity Hour at the Death Valley Visitor Center.

The third annual MarsFest will take place March 28-30, 2014. It will include field trips to other-worldly sites led by planetary scientists, as well as talks about planetary science and exploration. For more information, visit: http://www.seti.org/seti-institute/marsfest-2014

Hope to see you there!

Author: Andrea Jones

A collection of SAM science results as of mid December 2013 are compiled on the Spaceflight 101 website.


Author: Paul Mahaffy

SAM has many different types of experiments it can run, but one of the more exciting results (for me) came from an experiment we ran on the Cumberland mudstone Curiosity drilled. On Earth, we can use a set of techniques to help determine the age of rocks. This had never been done before on another planet. But now, with SAM, we were able to apply similar techniques to obtain a formation age for a rock on Mars - for the very first time. The technique we used was potassium-argon dating (K-Ar), which measures how much argon gas a rock contains. Over time atoms of potassium-40 (an isotope of potassium which is radioactive) decay into the stable isotope argon-40. If we use the potassium measured from the APXS instrument on Curiosity, coupled with the amount of argon-40 SAM measures in a sample, we can calculate the age of the rock. Simple, right?

It turns out that running this experiment is not as simple as it seemed. On Earth, we have access to state-of-the-art laboratories where rock samples can be analyzed with several different instruments. Unfortunately, we have not been able to bring any rock samples from Mars back to Earth yet, so we had to design the experiment to work with the state-of-the-art laboratory we have on Mars: SAM! The rock age-dating experiment was developed and tested for many months on Earth using the SAM testbed, which is an identical running instrument we keep here at NASA Goddard Space Flight Center. In the procedure for the experiment, a powdered rock sample is heated to 1000 C to release all the gases within the sample, and the evolved gases are 'cleaned' up to remove all the gases we do not need for our analysis.

Once we got all the settings and experimental parameters correct and optimized, we ran the experiment on Mars - and got some amazing results! We measured a rock's age using the K-Ar dating technique, and obtained an age of 4.21 billion years. This measured age is similar to what we had predicted the age of the rock would be before the experiment. This may not seem like an exciting result, since the measured age of the rock matched our prediction, but it proved that the technique worked and that we could apply it to other rock samples as Curiosity climbs Mt. Sharp. The experiment worked!

For the full details, see the published paper in the journal Science.

Author: Charles Malespin