Using an unconventional research method, scientists are seeking to learn more about about Mars by flying a kite here on Earth. The method allows researchers to get a new look at geological features here at home that learn what they could reveal with the hopes of being able to identity similarities with what they see when examining the surface of Mars and potentially other planets and moons as well.
Scientists of the University of Arizona's Lunar and Planetary Laboratory have taken to kites that they fly above lava flows that cover the Hawaiian landscape to help them learn how to unravel the mysteries of Mars past.
These are no ordinary kites, however. The kites are equipped with cameras, a GPS and orientation sensors that can scan the terrain from high above. The team then combines these kites with powerful software algorithms to assemble tens of thousands of images into extremely detailed and accurate 3D digital terrain models. According to researchers, the project is unprecedented in both its scope and the quality of data that is being produced.
The goal of these studies is to help researchers gain the knowledge need to better interpret the images of the surface of Mars, taken with the HiRISE camera onboard NASA's Mars Reconnaissance Orbiter, which has been examining the surface of mars from orbit with six instruments since 2006.
"The idea is to understand places we can't go by analyzing places we can go," the principal investigator of the research team, who joined LPL in 2014 to establish a terrestrial analog research group, Christopher Hamilton says. Hamilton studies volcanic surfaces on Mars to understand the thermal history of the red planet, in other words, how the planet's internal processes manifest on the surface.
"We can use geologically young and vegetation-free surface features here on Earth - such as Hawaiian lava flows - as terrestrial analogs that can provide us with insights into processes that shape other planets," Hamilton says. "Instead of just saying, 'this feature looks like X,' we try to develop diagnostics that help us recognize the actual processes that led to the formation of a certain feature."
When scientists compared the terrain found at the Kilauea Volcano to that found on Mars, striking similarities began to appear.
"We think this is how the big lava flows formed on Mars, which strongly suggests they may not be what they seem. For example, many features that have been interpreted as channels carved by running water in the red planet's past are more likely to be the result of volcanic process that Hamilton describes as a "fill-and-spill" lava emplacement, which developed when lava accumulated in enormous "perched ponds" that breached like an overtopped dam, giving way to catastrophic floods of lava."
"It is easy to draw conclusions based on our intuition of how water flows," Hamilton says, "so it is tempting to interpret similar features on Mars in the same way. But in fact these features formed by flowing lava, not water."
The technique, called Multi-View Stereo-Photogrammetry, produces images that look much like aerial photos, but they are not actually photographs, they are image mosaics projected onto digital terrain models.
"The kite takes an image every two seconds, producing up to tens of thousands of photos of a site. The software then removes any distortion, and stitches those images together to create a virtual representation of the terrain that you would never have otherwise."
The process, called orthorectification, uses a massive amount of computing power but still takes weeks to completely render a model. However, the end justifies the means, as the result is an image with a resolution high enough to clearly show footprints in the sand.
"Our approach shows how the combination of ground-based observations and an aerial perspective can help us to decipher the geologic history of Earth and Mars."
