On this day, 2017: Hawaii telescope spots first known interstellar object
On October 19, 2017, a telescope in Hawaii spotted a faint object that had come from outside our solar system, Space.com and Radio Canada International reported. It was later named 'Oumuamua. It was the first object from another star system ever seen passing through ours, NASA and ESO said.
On October 19, 2017, astronomers using the Pan-STARRS1 telescope in Hawaii spotted a faint, fast-moving object, Space.com and Radio Canada International reported. It turned out to be the first known object to visit our solar system from interstellar space, NASA and the European Southern Observatory said.
Radio Canada International reported that the object was found by Canadian astronomer Robert Weryk at the University of Hawaii Institute for Astronomy. A NASA release from October 2017 also named Weryk as the first to spot it.
At first, astronomers thought it was a comet. Later checks found no cloud of gas and dust around it, so it was called an asteroid instead, Space.com reported. ESO said observations from its telescopes and others showed no sign of comet activity.
The object's path showed that it was not bound to the Sun. It was on a curved, open path that would carry it out of the solar system, Space.com reported. ESO said the orbit showed "beyond any doubt" that it had come from interstellar space.
In November 2017, it was named 'Oumuamua, which means "a messenger from afar arriving first" in Hawaiian, Space.com reported. It also got a new kind of label, 1I/2017 U1, in which the "I" stands for interstellar, Space.com reported.
By the time it was found, 'Oumuamua had already passed closest to the Sun, on September 9, and come within 15 million miles of Earth on October 14, Space.com reported. Matthew Holman, director of the Minor Planet Center, said it was probably more ice than rock, Space.com reported.
ESO's team later found a dark red object about 10 times as long as it was wide. ESO estimated it was at least 400 meters long. Radio Canada International described it as a huge cigar-shaped object unlike anything seen before.
What we know: 'Oumuamua was spotted on October 19, 2017, and was the first object from outside our solar system ever seen here.
What we don't: Which star system, if any, 'Oumuamua came from.
Where outlets agree Space.com and Radio Canada International report that 'Oumuamua was discovered on October 19, 2017, and NASA and ESO records give the same date.
Where they differ The outlets cited here report the same key facts so far.