Since its discovery in 2017, a mystery has surrounded the first known interstellar object to visit the solar system, an elongated, cigar-shaped body named ‘Oumuamua (Hawaiian for “a messenger from afar arriving first”).
A new study featured on April 13 in Nature Astronomy offers a first complete answer to the way it was formed, and where it got here from.
First author Yun Zhang at the National Astronomical Observatories of the Chinese Academy of Sciences and co-author Douglas N. C. Lin at the University of California, Santa Cruz, used computer simulations to indicate how objects like ‘Oumuamua can form under the influence of tidal forces like those experienced by Earth’s oceans. Their formation principle explains all of ‘Oumuamua’s unusual traits.
Found on October 19, 2017, by the Panoramic Survey Telescope and Speedy Response System 1 (Pan-STARRS1) in Hawaii, ‘Oumuamua is absolutely nothing like the rest in our solar system, in response to Zhang. Its dry floor, unusually elongated form, and puzzling motion even drove some scientists to wonder if it was an alien probe.
Astronomers had anticipated that the primary interstellar object they detected could be an icy body like a comet.
Icy objects like those populating the Oort cloud, a reservoir of comets within the outermost reaches of our photovoltaic system, evolve at very massive distances from their host stars, are rich in volatiles, and are sometimes tossed out of their host systems by gravitational interactions.
They’re highly evident due to the sublimation of volatile compounds, which creates a comet’s coma when it’s warmed by the sun. ‘Oumuamua’s dry appearance, nonetheless, is similar to rocky bodies like the solar system’s asteroids, indicating a different ejection situation.