Two years ago, at an automated telescope in Hawaii detected 'Oumuamua, the first known object from an interstellar space, passed through our solar system. Then in August, at an amateur astronomer in Crimea found a second interstellar visitor, 2I / Borisov,
Now, scientists are eagerly developing plans to explore their messengers from afar and to learn their secrets.
"Imagine something that's traveled Andreas Hein, an aerospace engineer at the Initiative for Interstellar Studies, Charfield, England. "What does it tell us about its origin? What do you have that orbit this alien sun? Does life propagate between stars? "
For now, answers are slowly falling in and out of observatories on the Earth, including an image of Borisov's new image being captured by the Hubble telescope. Come 2028, though, a European spacecraft called Comet Interceptor could be on his way to a letter encounter with another, as-yet-undetected interstellar object.
Hein and his colleagues have even grander project in mind Oumuamua or Borisov (or another interstellar object) as it speeds out of the solar system, reaching either one by the mid-2040s.
To Hein, launching Project Lyra would be akin to building humanity's first starship – and doing it on the cheap. "We do not have the capability of reaching another star system within the next few decades at least, but having the opportunity to study a big chunk of material from another star is a bit like flying to another star," he says.
The many mysteries surrounding 'Oumuamua ("oh moo-)"
Inching towards the interstellar visitors
uh moo-uh ").
Researchers anticipated that the vast majority of interstellar objects would not be like one. It was strangely elongated, like a half-mile-long cigar, tumbling as it went. It also displayed no comet-like tail, and it sped up slightly as it moved away from the sun. These oddities led Harvard astronomer Avi Loeb to float the controversial idea that 'Oumuamua might not be at all, but at alien spacecraft.'
In contrast, Borisov seems to closely resemble the comets in our own solar system. "It appears Oumuamua, "Loeb says.
Alas, the European Space Agency's Comet Interceptor wants to be unable to reach either of these objects. In fact, it was not designed to go after an interstellar object at all. The original plan was that, after its launch in 2028, the 1-ton spacecraft would park itself in orbit around the sun, waiting for a comet to arrive from The discovery of Oumuamua and Borisov has.
The discovery of Oumuamua and Borisov has the Comet Interceptor team reconsidering its plans. By one estimate, at any time there are about 100 interstellar objects within Jupiter's orbit around the sun – and there's a decent chance that at least one of them will come within range of the spacecraft.
"If an interstellar object happens to turn Colin Snodgrass, an astronomer at the University of Edinburgh, says
Although Comet Interceptor's flight past would be an interstellar visitor would be fast and brief, it could prove to be highly revealing. "It would be fascinating to see one up close," Snodgrass says. "Either it would look like nothing else before, and it would look surprisingly familiar, implying that there are some universal similarities in planetary systems."
Hit the space accelerator
If you want to chase down 'Oumuamua or Borisov to determine their true nature, you'll need a spacecraft with a more oomph than Comet Interceptor. 'Oumuamua is now more than 1 billion miles from Earth and speeding away from 18 miles per second. Borisov wants to make his closest approach to the sun Dec.
That's where Project Lyra comes in. The engineers at the non-profit Initiative for Interstellar Studies came up with this concept based on their research into technologies for advanced space travel , Oberth maneuver, in which a spacecraft swoops to within 2 million miles of the sun and then fires its full-blast to slingshot toward its target. Using a giant rocket like NASA's long-awaited space launch system, combined with solid-rocket boosters, they could not get more than 12 miles per second.
With a 100 pounds to 'Oumuamua by 2048. Slowing down at the other end would be another challenge.
Surviving the sun's intense heat may make it easier to solve. NASA's current Parker Solar Probe, which is now swinging within 4 million miles of the sun during the 2020s, is testing a carbon composite heat shield that can effectively withstand temperatures of 2,500 degrees Fahrenheit.
Aliens closer to home
But There is another way to accelerate a mission to an interstellar object. Loeb notes that not all of the incoming objects head back to the stars. He calculates that some might get deflected by Jupiter's gravity and trapped into orbit around the sun. If so, a conventional spacecraft could reach them in a matter of years.
"There are already a number of candidates known," Loeb says. He cites in particular 2015 BZ509, a recent discovery of asteroid orbits near Jupiter but in the opposite direction of all the planets – a sign of an interstellar origin.
Loeb So proposes scouring the surface of the moon for debris left by other interstellar objects that have crashed there over billions of years of lunar history. That's a timely suggestion, since NASA's Artemis program was able to send astronauts back to the moon as early as 2024.
The realization that so much interstellar material has passed through our solar system over the eons, with more coming all the time, provides another powerful motivation to study the incoming objects up close.
He's not talking about derelict alien spacecraft but about possible extraterrestrial microorganisms or their remains, which in many ways would just as shocking. Finding such evidence would make the difference between the stars and across the galaxy, "Loeb says – and that humans could be descended from extraterrestrial microbes that landed on Earth billions of years ago.  It's a Hollywood-worthy twist: We're looking for the interstellar visitors, but they've come out of it all.
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