Comet CG Evaporates
Explanation:
Where do comet tails come from?
There are no obvious places on the
nuclei
of comets from which the
jets that create
comet tails emanate.
One of the best images of emerging jets is shown in the
featured picture, taken in 2015 by ESA's robotic
Rosetta spacecraft that orbited
Comet 67P/Churyumov-Gerasimenko
(Comet CG) from 2014 to 2016.
The picture shows plumes of gas and dust escaping numerous places from
Comet CG's nucleus as it neared
the Sun
and heated up.
The comet has two prominent lobes, the larger one spanning about 4 kilometers, and
a smaller 2.5-kilometer lobe connected by a narrow neck.
Analyses indicate that
evaporation must be taking
place well inside the comet's surface to create the
jets of dust and ice that we see emitted through the surface.
Comet CG (also known as Comet 67P) loses in jets about
a meter of radius during each of its 6.44-year orbits around the Sun, a rate at which
will completely destroy the comet in only thousands of years.
In 2016,
Rosetta's
mission ended
with a controlled impact onto Comet CG's surface.
Outreach Astronomers:
Future APOD writers sought.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
