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Nov 3, 2017
A/2017 U1: An Interstellar Visitor
Image Credit & Copyright: Astronomy Picture of the Day -- http://apod.nasa.gov/apod/astropix.html
Courtesy of http://apod.nasa.gov/apod/astropix.html
A/2017 U1: An Interstellar Visitor
Image Credit & Copyright: Astronomy Picture of the Day -- http://apod.nasa.gov/apod/astropix.html
Courtesy of http://apod.nasa.gov/apod/astropix.html
Traveling
at high velocity along an extreme hyperbolic orbit and making
a hairpin turn as it swung past the Sun,
the now designated A/2017 U1 is the first known
small body from interstellar space.
A point of light centered in this 5 minute exposure recorded
with the William Herschel Telescope in the Canary Islands on October 28, the
interstellar visitor is asteroid-like with
no
signs of cometary activity.
Faint background stars appear streaked because the massive 4.2 meter
diameter telescope is tracking the rapidly moving A/2017 U1
in the field of view.
Astronomer Rob Weryk (IfA)
first
recognized the moving object in nightly Pan-STARRS sky survey
data on October 19.
A/2017 is presently outbound,
never to return to
the Solar System, and already only visible
from planet Earth
in large optical telescopes.
Though an interstellar origin has been established based on its orbit,
it is still unknown how long the object could have
drifted among the
stars of the Milky Way.
But its interstellar cruise speed would be about 26 kilometers per
second.
By comparison humanity's Voyager 1 spacecraft travels about 17
kilometers per second
through interstellar space.
