Interstellar objects like 'Oumuamua could trigger the formation of a planet

& # 39; Oumuamua could form the heart of a alien planet One day.

Widely stray bodies such as weird, needle-shaped & # 39; Oumuamua – the first interstellar object ever confirmed in our own solar system – a new study suggests that nascent planetary systems are usually a seed.

Such visitors probably serve as scaffolding, allowing extraterrestrial worlds to take shape much faster than they would otherwise, researchers said.

Related: & # 39; Oumuamua: our first interstellar visitor explained in photos

"For decades, we've been studying how planets go from millimeter grains to gigantic planets like Jupiters." This growth process would be very slow, but the observations tell us the opposite: some planets exist around very young stars " , the lead author of the study, Susanne Pfalzner, of the Jülich Supercomputing Center and the Max Planck Institute for Radioastronomy in Germany, said in a statement.

"The presence of 100 meters [330 feet] The objects contained in this gravel could dramatically speed up the formation process of the planet, "said Pfalzner. By drawing gravel and gas from the surrounding disk, some of the old interstellar objects could become complete planets. "

& # 39; Oumuamua was previewed for the first time zooming through the inner solar system in October 2017. The strange trajectory of the object revealed that it was coming from very far away and subsequent observations intensified the plot. "Oumuamua is a reflective and narrow object, maybe six times longer than wide, and it seems to be rocking in a strange way.

The collective characteristics of the interstellar visitor have given rise to speculation that could be an extraterrestrial spaceship some kinds. Most scientists however think that it is an inert piece of rock and ice. His probably a comet this idea was ejected from its native system a long time ago by a gravitational encounter with a migratory planet or a neighboring star.

The fact that astronomers have seen Oumuamua indicates that such unattached objects are incredibly abundant in our Milky Way galaxy. And that would mean that they often fall into newly formed solar systems, according to the new study.

Indeed, Pfalzner and co-author Michele Bannister, an astrophysicist at Queen's University in Belfast, Northern Ireland, have calculated that every protoplanetary disk surrounding a newborn star probably contains at least 10 million. interstellar objects at least as large as Oumuamua. (& # 39;) The exact size of Oumuamua is unknown.Scientists believe that it measures less than 2,600 feet, or 800 m, in its largest dimension.)

"At such initial sizes, the growth process of these planetesimals of seed in the protoplanetary disks rich in gas and dust should be considerably accelerated," writes the duo in the new document published online today (April 8 ) in The Letters of the Astrophysical Journal. (You can read it for free on the pre-print site online arXiv.org.)

"The consequences of this discovery could be of great significance," said Bannister in the same statement. "Throughout the galaxy, the debris of the planetary systems of the past would help build the next generation of planetary systems.Every new generation of stars would increase the abundance of interstellar objects in the space."

Mike Wall's book on the search for extraterrestrial life, "Over there"(Grand Central Publishing, 2018, illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on twitter @Spacedotcom or Facebook.