In June, a mysterious object was spotted hurtling through the inner solar system on a hyperbolic path. It was later confirmed as an interstellar object, the third such entity from outside our solar system to be seen in the night skies. The rare discovery has prompted a scientific scramble to understand the object and its origins, including potential probes to study it up close.
Scientists at the Southwest Research Institute (SwRI) put together a mission study that outlines how a spacecraft could conduct a flyby of an interstellar object as it makes its way through the solar system. Although it’s too late for such a mission to intercept the recently discovered 3I/Atlas, the scientists used the comet-like object’s observed properties to design the spacecraft, required payloads, and scientific objectives so that they can prepare for the next interstellar visitor.
“The trajectory of 3I/ATLAS is within the interceptable range of the mission we designed, and the scientific observations made during such a flyby would be groundbreaking,” SwRI’s Matthew Freeman, the study’s project manager, said in a statement. “The proposed mission would be a high-speed, head-on flyby that would collect a large amount of valuable data and could also serve as a model for future missions to other ISCs.”
3I/ATLAS was first spotted in data collected by the Asteroid Terrestrial-impact Last Alert System (ATLAS) between June 25 and 29, and then again on July 1. Based on initial observations, scientists determined that the object was moving too fast to be bound by the Sun’s gravity and that it’s on a hyperbolic trajectory, meaning that it doesn’t follow a closed orbital path around our star, according to NASA. The International Astronomical Union’s Minor Planet Center confirmed that this likely comet came from outside our solar system on July 2, marking the third discovery of an interstellar object.
‘Oumuamua was the first known interstellar object, detected by the Pan-STARRS1 telescope in Hawaii as it was surveying the sky on October 19, 2017. Two years later, amateur astronomer Gennady Borisov spotted the second known interstellar object, which was named 2I/Borisov. Scientists estimate that there are many more objects of this kind passing within Earth’s neighborhood each year, and it may become easier to spot them with new astronomical facilities such as the Vera Rubin observatory.
“These new kinds of objects offer humankind the first feasible opportunity to closely explore bodies formed in other star systems,” Alan Stern, associate vice president of SwRI who led the study project, said in a statement. “An [interstellar comet] flyby could give unprecedented insights into the composition, structure and properties of these objects, and it would significantly expand our understanding of solid body formation processes in other star systems.”
Intriguingly, 3I/Atlas is set for a flyby of Mars on October 3, when the object will come as close as around 18.6 million miles (30 million kilometers) from the Red Planet. The European Space Agency is preparing to observe the interstellar object using spacecraft orbiting Mars, namely the Mars Express and the ExoMars Trace Gas Orbiter, according to Space.com. The object may be too far for some detailed observations, but the spacecraft will at least help resolve 3I/Atlas’ shape and attempt to measure its spectrum in search of molecular signatures that could shed light on its mysterious origins.