Should Earthlings Chase ‘Oumuamua Into Interstellar Space?
In October 2017, an asteroid-hunting telescope in Hawaii detected something unusual. A cigar-shaped object about twice the size of the Eiffel Tower was booking it past Earth at nearly 60,000 miles per hour—and appeared to be accelerating. Known as ‘Oumuamua, a Hawaiian word meaning “scout,” the object had the characteristics of both a comet and an asteroid. Its bizarre features led astronomers to conclude that it was a cosmic interloper: a giant chunk of rock that was formed in another star system and blasted on a journey through interstellar space billions of years ago.
‘Oumuamua was the first interstellar object ever detected in our solar system. For the last three years there’s been a steady stream of research papers hypothesizing about its origin, its chemistry, and even the possibility that it might be an alien spacecraft. The asteroid is rapidly receding into deep space, which makes it difficult to observe using telescopes on Earth. This means that many of the questions about ‘Oumuamua may never be answered—unless, of course, we send a spacecraft to intercept it.
This is the goal of Project Lyra, a mission proposed by a British nonprofit called the Initiative for Interstellar Studies, which funds education and research projects focused on taking us to the stars. The group announced Project Lyra just two weeks after ‘Oumuamua’s discovery and in May, Acta Astronautica will publish the updated version of their proposed mission to chase down the asteroid.
“We now know such a mission, at least in principle, is achievable,” says software developer Adam Hibberd, a volunteer with the initiative who built the software to design Project Lyra’s trajectory. “The possible scientific return would be tremendous and might fundamentally alter our understanding of our place in the universe.”
‘Oumuamua is currently moving away from Earth at nearly twice the speed of Voyager 1, the fastest spacecraft ever built. The asteroid travels about 500 million miles per year—the average distance between the Earth and Jupiter—which means it will enter interstellar space sometime in the late 2030s. To catch up with the asteroid, Project Lyra proposes launching a spacecraft on one of the world’s most powerful rockets—either SpaceX’s Falcon Heavy or NASA’s forthcoming Space Launch System—and using gravity assists from Jupiter and the sun to slingshot the craft toward the asteroid. The spacecraft would be outfitted with a rocket booster that would fire as it whipped around the sun to help bring it up to speed.
Project Lyra’s new mission proposal suggests launching the spacecraft as soon as 2030. It would intercept ‘Oumuamua around 2049 when the asteroid is about five times farther from the sun than Pluto. For the sake of comparison, Voyager 1, which has gone deeper into interstellar space than any human made object in history, has traveled 15 billion miles in 40 years. The Project Lyra spacecraft would have to travel 20 billion miles in half that time.
“Unfortunately we can’t just launch any year we like,” says Hibberd. “To make missions feasible using current technology, we are reliant on Jupiter taking up a certain point in its 12-year orbit around the sun, and so the opportunities follow approximately a 12-year cycle.”
Marshall Eubanks, the chief scientist at Space Initiatives, a company working on small satellite systems, and a coauthor of the new Project Lyra paper, sees the mission as a stepping stone toward more ambitious interstellar missions. For example, Breakthrough Starshot, an interstellar mission bankrolled by the billionaire Yuri Milner, wants to use giant lasers to send a fleet of thumbnail-sized probes to our closest stellar neighbor, Alpha Centauri. Eubanks says that an interstellar mission to ‘Oumuamua would be “far easier” than travelling to Alpha Centauri. But he acknowledges that the mission would still face a host of challenges, including simply finding ‘Oumuamua in the wilderness of interstellar space.
