Earlier this year, astronomers spotted a mysterious interstellar object, dubbed 3I/ATLAS, hurtling through the solar system at a blistering speed.
It’s only the third confirmed interstellar object to have ventured into our solar system — all over the past few years, owing to more sophisticated space-observing technology — and scientists are eager to have a closer look.
Besides detailed observations by the Very Large Telescope in Chile and NASA’s Hubble Space Telescope, Harvard astronomer and alien hunter Avi Loeb called on using the space agency’s Juno spacecraft to intercept the object’s path to get a first-hand look.
Loeb, who made headlines last month after suggesting 3I/ATLAS may be an alien probe sent by an intelligent civilization, argued in a blog post that the “close encounter of 3I/ATLAS to Jupiter provides a rare opportunity to shift Juno from its current orbit around Jupiter to intercept the path of 3I/ATLAS at its closest approach to Jupiter.”
The unique opportunity caught the attention of Representative Anna Paulina Luna (R-FL), who sent a letter to acting NASA administrator Sean Duffy, encouraging the agency to follow Loeb’s suggestion.
“It is recommended that NASA conduct a study to assess how much fuel is left in Juno’s engine, and I support an extension of the Juno mission at least until mid-March 2026 at a cost of about $15M per 6 months from the current expiration date of mid-September 2025,” the letter reads.
Experts, however, were quick to throw cold water on Loeb’s plan, which happens to resemble the plot of Stanley Kubrick’s 1968 sci-fi epic “2001: A Space Odyssey.”
“Juno does not have enough fuel to visit 3I/ATLAS,” Penn State astronomy professor Jason Wright tweeted. “Its main engine is also malfunctioning. [Loeb] does (or should) know this because his team was in touch with [Juno principal investigator Scott Bolton].”
“An extended mission for Juno would be awesome, but a visit to 3I/ATLAS makes no sense,” he added.
The spacecraft was launched almost exactly 14 years ago, entering a polar orbit of Jupiter roughly five years later. It was only planned to study the planet until 2018, but it has since doubled the length of its originally planned mission.
Not everybody agrees that a mission to visit 3I/ATLAS is out of the question, though.
Juno’s “current orbit allows it to view Jupiter up close, and its visits to Io [a moon of Jupiter] in 2023 [and] 2024 exposed it to a lot of radiation,” University of Kent space professor Mark Burchell told New Scientist. “So it is no surprise it is now showing anomalies in performance that need rebooting.”
“Could it be re-tasked?” he added. “In theory, if it can be done, and the instruments work, then there is novel data there.”
Unsurprisingly, intercepting an interstellar visitor that’s screaming through outer space at 37 miles per second would be no easy feat even with brand new hardware. Any mission would need a lot of fuel and time to get anywhere near it.
According to a yet-to-be-peer-reviewed paper by a team from Michigan State University, a new mission would need to accelerate at 15 miles per second on the day of discovery — which was July 1, so the clock is ticking — to get there in time.
However, “spacecraft at Mars could be used to make valuable observations” around late November, when 3I/ATLAS hits its perihelion, or when it makes its closest approach to the Sun.
“The perihelion of 3I/ATLAS will not be easily observable from Earth-based observatories, as the object will be on the opposite side of the Sun and at a low solar elongation angle,” the paper reads. “However, the object will approach within 0.19 au [or 17.6 million miles] of Mars, and we encourage nearby spacecraft equipped with visible, UV, and IR spectrographs and cameras to attempt to capture data on this object’s closest approach.”
The European Space Agency’s Jupiter Icy Moons Explorer (JUICE) may also be able to get a look. The agency’s Luca Conversi told New Scientist that “we are aware of this precious opportunity and are currently exploring the technical feasibility.”
“I’m not sure it is feasible to send it to the comet: unfortunately astro-dynamics is more complicated than what we see in sci-fi movies,” he added, “and it is not easy to change the course of spacecraft.”
Time is quickly running out, and visiting 3I/ATLAS is starting to look like a Herculean task. But to scientists, it’s an endeavor worth exploring nonetheless.
“The closest approach to Earth will be in December,” said coauthor and fourth-year Michigan State undergraduate Atsuhiro Yaginuma in a press release last month. “It would require a lot of fuel and a lot of rapid mobilization from people here on Earth.”
“But getting close to an interstellar object could be a once-in-a-lifetime opportunity,” he added.
More on the object: Existing NASA Spacecraft Could Intercept the Weird Interstellar Object Cruising Into Our Star System