Blog Archives

The First-Known Interstellar Asteroid is Like a Giant Tumbling Torpedo

Artist’s impression of the 400-meter-long interstellar asteroid 1I/2017 U1 `Oumuamua. Credit: ESO/M. Kornmesser.

Remember that comet-no-wait-asteroid astronomers discovered in October on a high-velocity hyperbolic orbit around the Sun? It has been determined that the object must be of interstellar origin and, based on follow-up observations over the past several weeks, it’s shaped like nothing that’s ever been seen before.

Read the rest of this entry


We May Have Just Been Visited By An Interstellar Comet

“This object came from outside our solar system.”
— Rob Weryk, postdoctoral researcher at University of Hawaii’s Institute for Astronomy

Diagram of the path of C/2017 U1 PanSTARRS (now A/2017 U1), a possible interstellar comet (or asteroid) spotted on Oct. 18, 2017. (NASA/JPL)

On October 14, 2017, what appears to be a comet (er, make that asteroid…read more below) sped past Earth at a distance of about 15 million miles after swinging around the Sun. It had come within 23.4 million miles of our home star over a month earlier on Sept. 9, and in fact wasn’t spotted by astronomers until Oct. 18—four days after its closest pass by us.

Further observations showed that the approximately 525-foot-wide object (an estimate based on its reflectivity) first approached traveling 16 miles a second from the direction of the constellation Lyra—quite a high angle from the plane of the rest of the Solar System—and is on a hyperbolic trajectory, moving quickly enough both in- and outbound along its course to permanently escape the Sun’s gravity unlike any other comet asteroid ever observed.

Read the rest of this entry

A Comet and the Crescent Moon

Comet Pan-STARRS captured by Dr. Travis Rector from Alaska on 12 March 2013

Comet Pan-STARRS seen from Alaska on 12 March 2013 © Travis A. Rector

As comet Pan-STARRS heads back out into the depths of the Solar System, it’s become visible to skywatchers in the northern hemisphere (after several weeks of putting on a show in southern skies.) While poor viewing due to weather confounded some over the past few days, many people did get some great views of this cosmic visitor — such as the image above, captured on the night of March 12 by Dr. Travis A. Rector from the Menaker Observatory in Anchorage, Alaska.

“Comet Pan-STARRS is the very faint dot just below the center of the image,” Dr. Rector wrote on his website. “Its tail is pointed towards the upper-left corner. This picture was taken on its greatest elongation from the Sun. Nonetheless it was very hard to see. And nearly impossible to see by the naked eye.”

See a couple more images of Pan-STARRS below:

Read the rest of this entry

%d bloggers like this: