
Explanation:
In Greek myth Prometheus was a Titan,
known for bringing fire from Mount Olympus.
But in modern times the name is given to a
small
moon of Saturn, orbiting just inside Saturn's F ring.
In a complex interaction, the tiny
potato-shaped moon interacts
with the icy ring particles creating structures
along
the F ring still not fully understood.
One of the highest resolution views of
Prometheus,
this image of its
pocked surface posing with the thin F ring in the background
was taken during the Cassini spacecraft's close approach on December 6, 2015.
Prometheus is about 86 kilometers (50 miles) across.
High Energy Andromeda
Image Credit:
NASA, JPL-Caltech, GSFC,
NuSTAR,
GALEX,
Explanation:
A mere 2.5 million
light-years away, the Andromeda Galaxy, also known
as M31, really is just next door as large galaxies go.
In this (inset) scan, image data from NASA's
Nuclear
Spectrosopic Telescope Array has yielded
the best high-energy X-ray view yet of our large neighboring spiral,
revealing some 40 extreme
sources of X-rays,
X-ray binary star systems that contain a black hole or neutron
star orbiting a more normal stellar companion.
In fact, larger Andromeda and our own Milky Way
are the most massive members of the local galaxy group.
Andromeda is close enough that NuSTAR can examine
its population of X-ray binaries in detail,
comparing them to our own.
The background image
of Andromeda was taken by NASA's Galaxy Evolution
Explorer in energetic ultraviolet light.

Explanation:
On the Moon, the Earth never rises -- or sets.
If you were to sit on the surface of the Moon, you would see the Earth just hang in the sky.
This is because the Moon always keeps the
same side toward the Earth.
Curiously, the
featured image does picture the Earth setting over a lunar edge.
This was possible because the image was taken from a spacecraft
orbiting the Moon - specifically the
Lunar Reconnaissance Orbiter (LRO).
In fact, LRO orbits the Moon so fast that, from the spacecraft, the
Earth appears to
set anew about every two hours.
The
featured image
captured one such Earthset about three months ago.
By contrast, from the surface of the Earth, the
Moon sets about once a day -- with the
primary cause being the rotation of the Earth.
LRO was launched in 2009 and,
while creating a detailed three dimensional map of the
Moon's surface,
is also
surveying the Moon for
water and possible good landing spots for
future astronauts.


Infrared Portrait of the Large Magellanic Cloud
Image Credit:
ESA /
NASA /
JPL-Caltech / STScI
Explanation:
Cosmic dust clouds ripple across
this infrared portrait
of our Milky Way's
satellite
galaxy, the Large Magellanic Cloud.
In fact, the remarkable composite image from the
Herschel
Space Observatory and the
Spitzer Space
Telescope
show that dust clouds fill this neighboring dwarf galaxy, much like
dust along the plane of the Milky Way
itself.
The dust
temperatures
tend to trace star forming activity.
Spitzer data in blue hues indicate warm dust heated
by young stars.
Herschel's instruments contributed the image data shown in red and
green, revealing dust emission from cooler and intermediate regions
where star formation is just beginning or has stopped.
Dominated by dust emission, the Large Magellanic Cloud's
infrared appearance is different
from
views in optical images.
But this galaxy's well-known
Tarantula Nebula still stands out,
easily seen here as the brightest region to the left of center.
A mere 160,000 light-years distant,
the Large Cloud of Magellan
is about 30,000 light-years across.

Explanation:
Informally named Wright Mons, a broad mountain about
150 kilometers across and 4 kilometers high with
a wide, deep summit depression is featured in
this inset image
captured during the New Horizons flyby of Pluto in July 2015.
Of course, broad mountains with summit craters are found
elsewhere in the Solar System, like the large shield volcano
Mauna Loa on planet Earth or giant
Olympus Mons on Mars.
New Horizons scientists note the striking similarity of
Pluto's Wright Mons, and
nearby Piccard Mons, to large shield volcanoes suggests
the two could be giant cryovolcanoes that once erupted
molten ice from the interior of the cold, distant world.
In fact, found on a frozen dwarf planet Wright Mons
could be the largest volcano in the outer Solar System.
Since only one impact crater has been identified on its slopes,
Wright Mons may well have been active late in Pluto's history.
This
highest resolution
color image also reveals red material sparsely scattered around the region.