Detecting an interstellar object

The second interstellar comet sighting has recently been
made, only two years after ‘Oumuamua was discovered.

Astronomers^[1]
believe they have detected another space rock that was formed in a
distant system before traveling across space to reach our solar
system.

The object, a comet named C/2019 Q4 (Borisov), was
recently sighted by the Minor Planet Center.

^[2]

RELATED: ‘OUMUAMUA: SCIENTISTS NOW
SAY THE BIZARRE CIGAR-SHAPED OBJECT IS SADLY NOT AN ALIEN
SPACECRAFT^[3]

Detecting an interstellar object

How do astronomers know an object has come from outside of our
solar system? As the Smithsonian^[4] reports, it’s down
to speed and trajectory. According to observations made of
the comet, C/2019 Q4 is moving too fast — it’s going at
approximately 30.7 kilometers per second
(68,700 miles per hour) — to have originated in
our own solar system.

The comet^[5]
was first observed by Gennady Borisov, a Ukrainian amateur
astronomer at the Crimean Astrophysical Observatory, on 30
August.

An interstellar traveler

As the National Geographic^[6][7] reports, the
space rock will come to within 180 million miles
of Earth on 29 December and will make its closest approach to the
Sun on 7 December. After passing the Sun, it will slingshot back
out of our solar into interstellar space.

Here is an animation of C/2019 Q4 #C2019Q4https://t.co/3lgsl0NxzV pic.twitter.com/pK2Ucn5HMd^[8][9][10]

Observations by astronomers have allowed them to determine
that C/2019 Q4 is two miles wide, with a coma of gas and dust that
surrounds the object as it moves through
space.

“Based on the available observations, the orbit solution for
this object has converged to the hyperbolic elements shown below,
which would indicate an interstellar origin,” a statement^[12] from the Minor Planet
Center says. 

“Further observations are clearly very desirable.”

As it makes its closest approach to Earth, astronomers
will point their telescopes to the sky to confirm whether this is,
in fact, another interstellar comet.

A study on the initial observations of the comet was
published today in Nature Astronomy^[13].