By Cameron Delfin
If you asked Joachim Moeyens what an astronomer does, he wouldn’t tell you that it’s looking through a telescope.
For him, it’s developing software to understand what’s going on in the cosmos.
“I can count on one hand the number of times that I’ve actually looked through a telescope,” said Moeyens.
But that doesn’t mean his work isn’t crucial to important discoveries in space.
As a research software engineer at DiRAC, Moeyens’ work contributes to asteroid discoveries in the universe. He’s created an algorithm that innovates the way asteroids are discovered, enabling observations from data sets intended for other uses. According to Moeyens, he will use this algorithm to discover asteroids from public data generated by the Rubin Observatory in Chile.
Additionally, his work has the potential to discover dangerous asteroids that might hit the Earth. An improved version of his algorithm could help the Rubin Observatory discover more potentially hazardous asteroids than it otherwise would be able to.
“We’re leaving less of the population undiscovered that might actually have a devastating effect if they were going to hit the Earth,” said Moeyens.
During his undergraduate study at the University of Washington from 2010 to 2015, Moeyens completed a research project with Željko Ivezić, Rubin Observatory director. They continued to work together, with Ivezić encouraging Moeyens to apply to graduate school. There, he began working on asteroid science with Mario Jurić, DiRAC director.
“I feel fortunate that I came here to the University of Washington because I don’t think I would’ve had the opportunities that I’ve had had I not picked here,” said Moeyens.
Moeyens initially hoped to become an aerospace engineer, but his studies led him to applied physics. He dove into astronomy when a friend suggested they take an astronomy elective together. With that, he’s found a way to combine his coding skills with a field adjacent to aerospace engineering, discovering that science and technology are interlinked.
“To do good science, you need to write good software. To do good software, you also have to have … good science. I really like that balance,” said Moeyens.
The connection between software and science resonates with Alec Koumjian, Head of Software Engineering at the B612 Foundation, an organization dedicated to protecting Earth from devastating asteroid impacts. DiRAC and the B612 Foundation work together to find and track asteroids.
“The software allows for computation and the computation allows for exploring many different possibilities,” said Koumjian. “… you use the science to restrict how you interpret those results.”
At DiRAC, Moeyens works with the Rubin Observatory to help paint a picture of what’s in the sky by identifying and tracking asteroids. When the Legacy Survey of Space and Time (LSST) kicks off at Rubin next year, researchers will have another resource to discover asteroids.
“It’s really about mapping what’s out there. It’s understanding our cosmic neighborhood,” said Moeyens.
Astronomers would traditionally discover asteroids by taking two images of the sky in one night and tracking the movement of light sources, according to Moeyens. Between the two images, stars wouldn’t move, but asteroids would.
Using those images, astronomers developed models to observe and predict the motion of asteroids. Those pairs of observations between images are called tracklets.
Moeyens’ Tracklet-less Heliocentric Orbit Recovery (THOR) algorithm enables asteroid discovery without the use of tracklets. THOR can link single observations from different nights rather than relying on tracklet pairs of observations in a single night.
According to Moeyens, THOR gives telescopes more freedom in how they observe the sky as the algorithm doesn’t require telescopes to follow a specific path to make tracklets. Since THOR’s method in capturing data is flexible, more datasets can be used to discover asteroids. And, THOR can make discoveries across different nights from different telescopes.
These insights enable asteroid impact prevention. However, the most difficult part of impact prevention isn’t intercepting asteroids. Instead, it’s discovering them, according to Former NASA Astronaut Ed Lu.
“That’s 99 percent of the battle,” said Lu.
Lu is the co-founder and executive director of the B612 Foundation. According to Lu, shifting the course of an asteroid so that it does not hit the Earth requires changing its velocity by about one millimeter per second.
This process has been proven possible by NASA. In 2022, they successfully sent a small spacecraft to strike an asteroid, according to the organization.
“Deflecting an asteroid means tiny nudges,” said Lu. “It’s really easy to deflect asteroids.”
On the flip side, that means that researchers have to be accurate to that strict margin in order to identify asteroids that might strike the Earth.
“The hard part is actually knowing that there’s an asteroid out there,” said Lu.
In the future, Moeyens says that he would like to take the discoveries that Rubin makes and use them to further enhance THOR. According to Moeyens, this would enable THOR to be used with different populations of asteroids or for tracking satellites.
No matter the challenge, Moeyens is up for it, using his trusty computer to get the job done – not a telescope.
“I like solving problems,” said Moeyens. “As long as I can write some software to help accomplish it – that would make me happy.”