NASA Taps MHC’s Dyar for Latest Mars Mission

Professor Darby Dyar

On August 6, the Mars Science Lab (MSL), one of the most complex science laboratories ever built, is expected to touch down on the surface of Mars and begin sending data back to Mission Control––which will, in turn, send that data to a lab on the Mount Holyoke campus.

MHC professor of astronomy Darby Dyar––who will watch the landing from Mission Control at the Jet Propulsion Lab in Pasadena––will be working with other scientists to provide expertise and support to daily mission operations. She’ll also work with MHC students to identify the composition of rocks and soil sent to Earth by the mission’s rover, Curiosity, which will carry the MSL over the planet’s surface.

In June, Dyar was awarded a $476,000 grant by NASA to undertake an analysis of data provided by Curiosity’s onboard ChemCam spectrometer. Through the grant, titled Enhancing Science Return from ChemCam through Laboratory and Statistical Analyses and Integration with APXS (Alpha Particle X-ray Spectrometer), she will analyze data on the elemental composition of rocks and soils on Mars. This work will help assess the potential for the planet to support life and characterize the climate and geology of Mars.

ChemCam is Curiosity’s most complex instrument, comprising a laser, camera, and spectrometer. Together, these instruments can identify the chemical makeup of Martian surface matter through laser-induced breakdown spectroscopy, or LIBS.

As part of the grant, a LIBS unit was installed by Los Alamos colleagues in Dyar’s lab at MHC in early July; there are only five such Mars-atmosphere units in existence, including the one inside Curiosity’s ChemCam.

Using the LIBS unit, Dyar, her lab manager Elly Breves, student Melissa Nelms '13, and recent graduates Marie Ozanne ’12 and Michelle DeVeaux ‘12 are developing a database of chemical analyses of Earth-based rocks and minerals, which will be used by Dyar and other scientists to identify the composition of minerals that Curiosity encounters on Mars.

“As soon as Curiosity lands, we expect to start receiving data for analysis within ten days,” said Dyar. During the mission, ChemCam could send more than 10,000 individual measurements to her and her colleagues on the international science team.

Using the College's LIBS unit, Dyar–who will alternate her work time between South Hadley and Pasadena–and her MHC team will provide project scientists with chemical compositions of thousands of terrestrial rock samples stored on campus. The samples will be placed inside a vacuum chamber with a slight partial pressure of carbon dioxide—which is set to imitate the atmospheric conditions on Mars—and then be zapped by the laser. The light emitted by the sample is collected by the unit and sent to a spectrometer, which “reads” the light and identifies the types of atoms within the sample.

“Each chemical element has its own unique fingerprint,” said Dyar. “By comparing the data collected by Curiosity with the information in Mount Holyoke’s database, project scientists will be able to identify the composition of the rocks and soil on Mars.

“This information will give us clues as to the environment in which the rock formed. The compositions of rocks that have been in contact with water differ from rocks that have not.”

The grant is the third awarded to Dyar by NASA, for a total of more than $1.5 million, for work on the ChemCam technique. As part of a 2009 NASA grant, Dyar and her team built ChemCam’s calibration target assembly that is housed on the front of the rover. The assembly holds rock sample standards from Earth, which will be used by scientists to test the accuracy of the rock compositions identified by Curiosity on the surface of Mars.

The grants have boosted MHC’s research reputation, said Dyar.

“We’re doing world-class research here and providing unheard-of opportunities for undergraduate science students, “ she said. “Not only will our students be operating the laser and developing the database that will be used by the Mars mission, but they will be among the first people to actually work with data generated by Curiosity’s ChemCam.”