For over 50 years, Cornell has made astronomical contributions in the ongoing efforts to explore and understand the mysterious inner workings of Earth’s rust-colored neighbor, Mars. In honor of these decades of research and discovery, The Sun illuminates the achievements of Cornellians past, present and future in their tireless expedition towards revealing the secrets of the Red Planet.
Why do scientists want to explore Mars? Proximity is a major reason, Prof. Jonathan Lunine, astronomy, said in an interview with The Sun.
Since Mars is a mere 140 million miles away —if the solar system were a football field, Earth and Mars would be one yard apart — a mission to Mars can be launched every two years with only one year required for the mission to reach the surface of the rocky planet, according to Lunine.
The unique geology of Mars also provides scientists with a major incentive to further explore what the planet has to offer.
“All [prior] exploration…shows that Mars…had a climate that might have been somewhat like the Earth’s, with warmer conditions, a thicker atmosphere [and] water in lakes and seas on the surface,” Lunine said. “That raises the possibility that maybe life existed on Mars at one time, and perhaps today the evidence for that life could be in the rock, in the sediments, and maybe even [now] there’s life deep underground.”
According to Lunine, further understanding Mars can be critical in establishing the evolution of smaller planets and whether these planets can support life as well.
“Cornell has a long history of this kind of exploration….if you go way back to the 1970s, Carl Sagan was involved in the very first Mars landers called Viking,” Lunine said. “That [was] the starting point for Cornell’s very long involvement in space missions to Mars and beyond.”
The orbiters allowed scientists to understand Mars’ atmospheric properties, scale of dust storms, and geology of different terrains, explained principal research scientist Don Banfield ’87, astronomy. The landers also captured images of local geology and performed experiments in an attempt to detect life.
“In a lot of ways, those were the best landers we’ve sent to Mars [to date] – they had a tremendous complement of instrumentation,” Banfield said. “We’re only just now matching them with our exploration of Mars in the last decade or so.”
In the decades since Viking, the most significant of Cornell’s contributions to Mars exploration was the scientific development of the two Mars Exploration Rovers — Spirit and Opportunity. Launched in 2003, the missions of the twin rovers were initially conceived in the 1990s by Prof. Emeritus Steven Squyres ’78 Ph.D. ’81, who then spearheaded the scientific aspects of bringing the missions to fruition.
“It was the first time that there were vehicles on the surface of Mars that could go a significant distance and actually sample rocks and soil from different places,” Lunine said.
Because of their ability to analyze the elemental composition of rocks on-site, Spirit and Opportunity discovered direct evidence that liquid water was once present on the surface of Mars, which could have possibly sustained microbial life, Lunine explained.
Although each vehicle was designed to last 90 days on the surface of Mars, Spirit completed its mission in 2011, while Opportunity finally gave out in June 2018 — transmitting information from Mars for 14 years.
Beyond the scientific development of the Mars Exploration Rovers, Cornell researchers have been involved in analyzing the data from the Mars orbiters, which provide a “global view of the surface of Mars” using imaging and mapping technologies, Lunine said.
Cornell was also directly involved in the Mars InSight Mission, which landed in November 2018 and sought to “understand the interior structure of Mars,” Banfield said. The immobile lander placed a very sensitive seismometer, a device that detects and records vibrations similar to earthquakes, coming from the interior of Mars.
Vibrational waves are detected differently depending on the materials through which they travel. The location and types of vibrational waves that are measured can therefore be used to determine properties of the core of Mars, like whether it’s liquid or solid.
Banfield was involved in developing meteorological technology that would measure potentially distracting atmospheric activity, which could then be subtracted from the detected vibrational — or seismic — waves.
“We’re trying to figure out…how does Mars work as a terrestrial planet? Does it have a core that’s overturning as vigorously as the Earth’s? Probably not…But we don’t know that for sure, and this is the way that we’re trying to figure that out,” Banfield said.
Over the past 18 years, Banfield has also been developing a weather station for Mars, which includes a higher-resolution, better-performing wind gauge than has ever been used before.
“That allows us to ask new questions about how the atmosphere interacts with the surface of Mars,” Banfield said.
Looking to the future, Cornell scientists are involved in the next Mars rover set to be launched in July 2020, which was recently named “Perseverance.” Prof. Alex Hayes, astronomy, has been working on the camera system to be fitted on the SUV-sized rover, Lunine noted.
According to Lunine, Perseverance will explore what is believed to be part of a dried-up river on the surface of Mars and collect sample tubes of sediments to drop them off in specific locations, because Perseverance itself cannot return back to Earth after it has landed on Mars. In the next decade, a new mission, Mars Sample Return, could then retrieve the samples and eventually take them back to Earth.
Cornell scientists, including Hayes, have developed a mission concept called CAESAR, which Lunine explained would land on a comet, collect samples, and return the materials back to Earth “all in a single shot.”
“We think that comets are the most primitive, unaltered material that we can access in the solar system…[so the mission] will tell us about how the planets were formed and what [materials] they were formed from,” Lunine said.
For both Banfield and Lunine, collaborating with fellow Cornell researchers and organizations like NASA has been truly rewarding.
“There’s something pretty exciting about commanding a spacecraft that’s sitting on the surface of Mars…all of that is helping us ask questions of where do we sit in the universe? What is special about Earth? Could Mars have held life back in the past?…That’s what we’re trying to address,” Banfield said.