2017 is proving once again to be a year of unprecedented firsts. A recent discovery by a team of astronomers certainly fits the description. They picked up images of a type of outer space rock: it’s the first visitor from beyond our solar system that’s ever been observed.
Now, the important task of observing, monitoring and analyzing the rock is underway, as scientists cannot be sure how long our foreign friend will stick around.
Karen Meech, an astronomer with the University of Hawaii Institute for Astronomy, expressed her excitement about the discovery: "We have long suspected that these objects should exist, because during the process of planet formation a lot of material should be ejected from planetary systems. What's most surprising is that we've never seen interstellar objects pass through before." In other words, this object represents an opportunity to both formulate new theories as well as confirm or disprove old ones about the specific relationships between matter in our solar system and adjoining solar systems.
Hawaii’s Pan-STARRS 1 telescope picked up images of the asteroid on October 19th travelling from the direction of the Lyra constellation. In terms of its dimensions, it’s relatively small, with a diamter of less than .4km. It’s moving quite fast, however, which explains the scramble to continue observations of the fleeting object: 25.4 kilometers per second, or 91,539 kilometers per hour.
Paul Chodas, manager of the California-based NASA Center for Near-Earth Object Studies, part of the Jet Propulsion Laboratory, explains the sense of urgency in documenting the asteroid:
"The orbit is very convincing. It is going so fast that it clearly came from outside the solar system," adding, "It's whipping around the Sun, it has already gone around the Sun, and it has actually gone past the Earth on its way out."
University of Hawaii-based postdoc Robert Weryk comments on the unusual movement of the object: "It became clear that it didn't move like asteroids and comets normally do," who cross-checked telescopic images to corroborate his theory that it had originated outside of our solar system.
"We might have, for moderately large telescopes, another handful of days, maybe a couple of weeks. So we don't have much time to study it," says Meech, who would like to continue to make guesses about the chemical composition of the asteroid to compare it to the makeup of objects from our own solar system.
"We've been expecting this for decades, really," Chodas says with assurance, adding, "We don't know enough about how much material is floating around between the stars. And so this will give us the first data point. We hope to find more of this stuff."
For now, our foreign visitor has not been named—beyond its technical name of A/2017 U1— and there’s been no talk of what name to give it, but it has accomplished its goal of stirring excitement among astronomers with its fleeting presence. We all look forward to viewing the Hubble Telescope images that will continue to emerge the next few weeks.