ASU examines Mars’ moon Phobos in a different light

October 4, 2017

NASA's longest-lived mission to Mars has gained its first look at the Martian moon Phobos, pursuing a deeper understanding by examining it in infrared wavelengths.

The Thermal Emission Imaging System (THEMIS) camera on NASA's Mars Odyssey orbiter observed Phobos on Sept. 29. THEMIS Principal Investigator Philip Christensen and THEMIS Mission Planner Jonathon Hill of ASU’s School of Earth and Space Exploration combined visible-wavelength and infrared data to produce an image color-coded for surface temperatures of this moon, which has been considered for a potential future human-mission outpost. Martian moon Phobos Temperature gradients: This image combines two products from the first pointing at the Martian moon Phobos by the THEMIS camera on NASA's Mars Odyssey orbiter on Sept. 29. Surface-temperature information from observation in thermal-infrared wavelengths is overlaid on a more detailed image from a visible-light observation. Image by NASA/JPL-Caltech/ASU/J. Bandfield, SSI Download Full Image

“Although THEMIS has been at Mars for 16 years, this was the first time we have been able to turn the spacecraft around to look at Phobos,” said Hill. “This half-moon view of Phobos was chosen because it allowed us to observe a wide range of temperatures on the surface.”

Looking across the image from left to right presents a sequence of times of day on the Martian moon, from before dawn, to sunrise, to increasing amounts of time after dawn. This provides information about how quickly the ground warms, which is related to the texture of the surface. As barefoot beach walks can confirm, sand warms or cools quicker than rocks or pavement.

"Including a predawn area in the observation is useful because all the heating from the previous day's sunshine has reached its minimum there," said THEMIS Deputy Principal Investigator Victoria Hamilton of the Southwest Research Institute. "As you go from predawn area to morning area you get to watch the heating behavior. If it heats up very quickly, it's likely not very rocky but dusty instead."

Phobos has an oblong shape with an average diameter of about 14 miles (22 kilometers). Cameras on other Mars orbiters have previously taken higher-resolution images of Phobos, but none with the infrared information available from THEMIS. Observations in multiple bands of thermal-infrared wavelengths can yield information about the mineral composition of the surface, as well as the surface texture.

One major question about Phobos and Mars' even smaller moon, Deimos, is whether they are captured asteroids or bits of Mars knocked into the sky by impacts. Compositional information from THEMIS might help pin down their origin.

Since Odyssey began orbiting the Red Planet in 2001, THEMIS has provided compositional and thermal-properties information from all over Mars, but never before imaged either Martian moon. The Sept. 29 observation was completed to validate that the spacecraft could safely do so, as the start of a possible series of observations of Phobos and Deimos in coming months.

This series of images was taken in visible-wavelength light as the THEMIS camera on NASA's Mars Odyssey scanned across the Martian moon Phobos on Sept. 29, 2017. The apparent motion is due to progression of the camera's pointing during 18 seconds of observing, not from motion of Phobos. Image Credit: NASA/JPL-Caltech/ASU

In normal operating mode, Odyssey keeps the THEMIS camera pointed straight down as the spacecraft orbits Mars. In 2014, the spacecraft team at Lockheed Martin Space Systems in Denver, NASA's Jet Propulsion Laboratory in Pasadena, California, and the THEMIS team at ASU developed procedures to rotate the spacecraft for upward-looking imaging of Comet Siding Spring as it passed near Mars. The teams have adapted those procedures for imaging the Martian moons.

"We now have the capability of rotating the spacecraft for THEMIS observations," said Odyssey Project Scientist Jeffrey Plaut of JPL. "There is heightened interest in Phobos because of the possibility that future astronauts could perhaps use it as an outpost."

With the first observation now in hand, plans are advancing for additional opportunities at different illumination phases of Phobos and Deimos.

“THEMIS has probably been the most interesting mission I’ve been a part of,” said Christensen. “We’ve learned a great deal about Mars, and it is very exciting to still be doing new and unique science 16 years after we got there.”

Karin Valentine

Media Relations & Marketing manager, School of Earth and Space Exploration


ASU sustainability efforts to shine at annual conference

October 4, 2017

Arizona State University will be represented at the Association for the Advancement of Sustainability in Higher Education (AASHE) annual conference this month, as staff from Environmental Health and Safety, University Sustainability Practices, Energy Innovation and the Zero Waste departments will shine a light on the ASU's broad range of sustainability programs. 

Environmental Health and Safety's John Svenson and Michael Ochs will be participating in the event for ASU, delivering a 30-minute presentation on ASU's Laboratory Standard and Design Guide. They will be exploring everything from lab ventilation and conditioning to talking about how a proper lab is monitored. bottles in lab Download Full Image

“All of our laboratories need adequate ventilation so chemicals don’t create exposure,” Ochs said. “There are regulations that require us to meet a certain minimum air changes in the lab while still keeping within regulatory requirements.”

With help from Svenson and Ochs, ASU is pushing to make as big of an impact on environmental safety as possible.

“There are so many different departments here,” Svenson said. “Everyone is always very open in collaborating and wants to reach similar goals as they try to make a positive impact on our environment.”

The university is also working towards improving air quality while conserving energy. Laboratories are designed to make a certain number of air changes per hour in an attempt to minimize the effects of hazardous chemicals, so Svenson and Ochs updated the EHS design guide to make those changes as small as possible.

“It’s important because if you do it properly you can reduce your carbon footprint and energy usage,” Svenson said. “Doing that while maintaining a safe environment to work in is critical.” 

This will be the fifth consecutive year that University Sustainability Practices has presented at the AASHE.

Not only does the conference provide a chance for ASU to shine on a national stage, but learning and networking opportunities also come with the trip.

“Networking with others who work in sustainability is a huge benefit for ASU,” Svenson said. “We also get to learn about some of the methods and procedures that other universities use and compare them to the programs we have here.”

This year’s conference will be held in San Antonio from October 15-18. 

Connor Pelton

Communications Writer, ASU Now