Explanation:
Early in November, small
but active
Comet Hartley 2 (103/P Hartley) became the
fifth comet
imaged close-up by a
spacecraft
from planet Earth.
Continuing its own
tour
of the solar system with a 6 year
orbital period, Hartley 2 is
now appearing in the
nautical
constellation Puppis.
Still a target for binoculars or small telescopes from dark sky
locations, the comet is captured in this composite image
from November 27, sharing the rich 2.5 degree wide
field of view
with some star clusters well known
to earthbound skygazers.
Below and right of the comet's alluring green coma lies
bright M47,
a young open star cluster some 80 milion years old,
about 1,600 light-years away.
Below and left open cluster
M46 is older,
around 300 million years of age, and 5,400 light-years distant.
Hartley 2's short, faint tail even extends
up and right
toward another fainter star cluster in the scene, NGC 2423.
On November 27, Comet Hartley 2 was about 2.25
light-minutes from Earth.
Sweeping toward
the bottom of this field, by November 28 the
comet's path had carried it between M46 and M47.
