A visitor from another star – that was the news some days after October 19, 2017, when scientists discovered a enigmatic cigar-shaped object screaming away from the solar system of nearly 57,000 mph (92,000 km / h). The device moved too fast to have originated from our own system and traveled on a U-shaped hyperbolic circuit that took it around the sun and sent it back into interstellar space.
Astronomers using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS 1) telescope in Hawaii uncovered the odd object that was first designated as A / 2017 U1. But soon it was given the name & # 39; Oumuamua which in Hawaiian means "scout" or "distant visitor first", according to international astronomical union. "Oumuamua: Solar System 1
" It has long been theorized that such objects exist – asteroids or comets move between the stars and occasionally pass through our solar system – but this is the first such disclosure, "said Paul Chodas, director of the Near Earth Object Studies Center at NASA's Jet Propulsion Laboratory in Pasadena, California, in a statement .
Scientists immediately trained as many telescopes at Oumuamua as possible to learn more about the object before it became too weak for any instrument to see. They found it to be between 1,300 feet (400 meters) and 2,600 feet (800 m) long and rather thin – maybe six times less in width than in length. The visitor tumbled over-over and had a dark red color that resembles other cold little objects in the outer solar system. Scientists stated that it had come from the constellation Lyra, although no one has yet figured out exactly which system it originates from .
So what is it?
Oumuamua was classified as the comet when it was first seen. But the fact that it did not produce a large puffy coma that flows out like a tail that comets usually do when heated by the sun, led astronomers to guess themselves. Some scientists claim that it was a rocky asteroid or perhaps even a new class of interstellar object.
Others have speculated & Oumuamua is a planetary ideal or a clump of rock usually built into a larger planet that was knocked out of its native system of gravity forces. And it can even be a zombie comet or more precisely "a tremendously fluffy aggregate of loosely bound dust grains", which put a paper on the idea behind a comet that struck together when it approached the sun.
Overall, the current consensus of the scientific community is that & # 39; Oumuamua is a comet because it moves a little faster than expected if it is just driven by gravity dragging from the sun. The most likely explanation is that the object is a release material that a comet makes which creates jets that push it together. Observations indicate that it is 10 times more reflective than our solar system's homemade comets, perhaps because Oumuamua's gassing has blown dust from the surface and reveals light ice below.
A visitor from outer space?
This jet-powered motion almost makes Oumuamua sound like a spacecraft that came from another star, took a quick pass through our system and then jumped away. Even astronomers have been fascinated by this opportunity, and researchers for Search for Extraterrestrial Intelligence (SETI) listened to any possible technological signals leaking from the object not even but twice . Both campaigns heard nothing.
Along with his co-author Shmuel Bialy, Avi Loeb of the Harvard-Smithsonian Center for Astrophysics published his own presumption that "Oumuamua was a gossamer-thin light sail (a type of propulsion using the sun's photons) from a advanced technological civilization, his argument focused on the fact that fumigation would have changed the visitor's rotation period – an effect that should have been easy to identify but not seen.
Loeb suggested that Oumuamua could be a interrupted piece of spacecraft randomly landing in our system or potentially an exploratory ship sent to our region. Few researchers have supported Loeb's allegations, but he claims to dismiss the possibility of foreigners out of hand removes useful hypotheses to be be acceptable parts of rational investigation. "" Science must be open, "he told Space.com when he first announced his idea.
After a t have seen & # 39; Oumuamua & # 39 ;, scientists are now eager to see other similar items. Greg Laughlin, an astronomer at Yale University, has estimated that there could be trillions in trillions by Oumuamua-like entities driving through the Growth Path. This gives credibility to the idea that microbes could have taken a trip to "Oumuamua-type objects in the past and spread through space – a theory known as panspermia.
Astronomers must not wait too long to Finding More Interstellar Items The Great Synoptic Survey Telescope (LSST) in Chile, scheduled to come online early next decade, will scan the night sky in unprecedented detail and discover another & # 39; Oumuamua or two .