Astronomers discovered the first interstellar object to visit our solar system on October 19, 2017. It was first spotted by Panoramic Survey Telescope and Rapid Response System 1 telescope situated at Haleakala Observatory, University of Hawaii. It was not easy to be described as it displayed both the characteristics of a comet and asteroid.
Researchers gave the formal name 1I/2017 U1 while it was commonly termed as ‘Oumuamua’, meaning “scout” in Hawaiian. Scientists from all over the globe collected as much data as possible before it went beyond the reach of the telescopes of our planet.
Few early reports speculated that it might have been an alien spacecraft meant to examine our solar system. However, all these claims were refuted by an analysis co-led by Matthew Knight, a researcher in the Department of Astronomy at the University of Maryland. It concluded that Oumuamua has a natural origin. The findings of the study were published in the Nature Astronomy journal.
Knight said that while it is exciting to come up with the hypothesis that it is an alien spacecraft, analysis suggests that there are a lot of natural phenomena that can explain it. Oumuamua is red in color, elongated and has a cigar-like shape. It also has an odd spin pattern. Scientists have found its motion through the solar system confusing. It appeared to accelerate in its trajectory but there has been no trail of gaseous emissions creating it. There is no discernable coma—the cloud of ice, dust, and gas that surrounds active comets—nor a dust tail or gas jets.
The International Space Science Institute in Bern was a home base for the collaboration of the researchers which included 14 scientists from the United States and Europe. The comprehensive analysis carried out by researchers gave the best possible explanation of the phenomenon. Knight explained that physical processes occurring near the Earth are considered to be universal. But the Oumuamua has been very weird and hard to explain.
Researchers considered a number of factors that can explain how Oumuamua escaped from its home system. One possible explanation is that it could have been ejected by a gas giant planet orbiting another star.
Researchers expect to observe more interstellar objects such as Oumuamua with the help of Large Synoptic Survey Telescope, scheduled to be operational in 2022. Only then scientists can find out by observing other objects if it is unusual or common.