A team of UCF researchers at the Arecibo Observatory in Puerto Rico are developing a technique that will help better defend against asteroids on track to collide with Earth.
The technique uses the same methods that make polarized sunglasses. According to the Planetary Sciences Journal, the polarization state of radar echoes from planetary bodies contains information about a planet's surface. Polarimetric radar scatter from surfaces, such as those observed for spacecraft-visited near-Earth asteroids, or NEAs.
The UCF study presents an improved method for analyzing a planet's polarimetric while studying ground-based radar observations of NEAs. Data gathered over the last seven years, is being used to develop the technique.
Lead Arecibo UCF researcher Dylan Hickson said that data found in the study can better tell us if an asteroid is porous, fluffy or rocky, which matters because there are hundreds of near-Earth asteroids that could potentially hit the planet.
“Learning more about the physical properties of asteroids is crucial in Planetary Defense,” Hickson said. “With our research, we can better prepare for potential asteroid impact events.”
Hickson said the team calculates images of NEAs and uses the images to discover polarimetric products, such as the degree of polarization, circular polarization ratio, and degree of linear polarization, the same method used when creating polarized sunglasses.
Depending on the size and composition, some asteroids will burn up in the atmosphere but others could cause catastrophic damage. Hickson said knowing how to deflect these potential threats will depend on what researchers know about the asteroid’s makeup.
Planetary sciences doctoral student Anicia Arredondo said learning about asteroid composition is important because asteroids are what is left over from when the planets formed. Arredondo said and by studying asteroids, we can learn information about what the solar system looked like when it was born.
Using polarimetric analyzation isn’t new, but it isn’t 100% reliable yet, according to Hickson. For example, scientists on NASA’s OSIRIS REx mission were surprised by how rocky asteroid Bennu was when they arrived last year to begin a sample collection mission. Images taken from the spacecraft found the surface to be much more rocky than initial radar data indicated, and the team had to adjust its sample target site, according to NASA.
Arredondo said despite NASA’s OSIRIS REx information from the mission not being 100% reliable, new technology helps us answer questions that we weren't able to answer before.
"Advancements like the NASA OSIRIS-REx mission that was impossible a few decades ago now give us so much information about what our solar system is like,” Arredondo said.
Hickson said more information is being discovered and the team will continue to publish new findings in the journal for the public to learn more about asteroids in space.
“Our results provide a methodology to extract more information, giving us a better picture of what these mysterious surfaces look like,” Hickson said. “Not only can this methodology be applied to data, but it can also be applied to future observations, potentially increasing our understanding of the broader asteroid population."