Dwarf Planet Ceres
Image Credit &
License:
NASA,
JPL-Caltech,
UCLA,
MPS,DLR,IDA -
Composition:
Justin Cowart
Explanation:
Dwarf
planet Ceres is the largest object in the Solar System's
main
asteroid belt,
with a diameter of about 950 kilometers (590 miles).
Ceres is seen here
in approximately true color,
based on image data from the Dawn spacecraft recorded on May 4, 2015.
On that date, Dawn's orbit stood 13,642 kilometers above
the surface of the small world.
Two of Ceres'
famous mysterious
bright spots at Oxo crater and Haulani crater are near center
and center right of this view.
Casting a telltale shadow at the bottom is Ceres' cone-shaped, lonely
mountain
Ahuna Mons.
Presently some 385 kilometers above the Cerean surface,
the ion-propelled Dawn spacecraft is
now
returning images from its closest mapping orbit.
Comet 67P from Spacecraft Rosetta
Image Credit & Licence:
ESA,
Rosetta,
NAVCAM
Explanation:
Spacecraft Rosetta continues to circle and map Comet Churyumov-Gerasimenko.
Crossing the inner Solar System for ten years to reach the vicinity of the comet in 2014, the robotic spacecraft continues to
image the unusual
double-lobed comet nucleus.
The
featured image, taken one year ago, shows dust and gas escaping from the comet's nucleus.
Although appearing bright here, the comet's
surface reflects only about four percent of
impinging visible light,
making it as
dark as coal.
Comet
67P/Churyumov–Gerasimenko spans about four kilometers in length and has a
surface gravity so low that an astronaut could
jump off of it.
With
Rosetta in tow,
Comet 67P
passed its closest to the Sun last year and is now headed back to the furthest point -- just past the orbit of
Jupiter.
Elliptical M60, Spiral NGC 4647
Image Credit &
Copyright:
NASA,
ESA,
Hubble Heritage Team
(STScI/AURA)
Explanation:
Giant elliptical galaxy M60 and spiral galaxy NGC 4647 do look like
an odd couple in
this sharp cosmic portrait
from the Hubble Space Telescope.
But they are found in a region of space where galaxies tend to gather,
on the eastern side of the nearby
Virgo
Galaxy
Cluster.
About 54 million light-years distant, bright M60's
simpler egg-like shape is created by its
randomly swarming older stars,
while NGC 4647's young blue stars, gas and dust are organized into
winding arms rotating in a flattened disk.
Spiral NGC 4647 is
estimated to be more distant
than M60, some 63 million light-years away.
Also known
as Arp 116,
the pair of galaxies may be on the
verge of a significant gravitational
encounter, though.
M60 (aka NGC 4649) is about 120,000 light-years across.
The smaller NGC 4647 spans around 90,000 light-years, about the size
of our own Milky Way.
Star Cluster R136 Bursts Out
Image Credit:
NASA,
ESA, &
F. Paresce (INAF-IASF),
R. O'Connell
(U. Virginia), & the
HST WFC3
Science Oversight Committee
Explanation:
In the center of star-forming region 30 Doradus lies a huge cluster
containing some of the largest, hottest, and most massive stars known.
These stars, known collectively as
star cluster R136, were captured in the
featured image in
visible light by the
Wide Field Camera 3 in 2009 peering through the
Hubble Space Telescope.
Gas and
dust clouds in
30 Doradus, also known as the
Tarantula Nebula,
have been sculpted into elongated shapes by powerful
winds and
ultraviolet radiation
from these hot cluster stars.
The
30 Doradus Nebula
lies
within a neighboring galaxy known as the
Large Magellanic Cloud and is located a mere 170,000
light-years away.
21st Century M101
Image Credit:
NASA,
ESA,
CXC,
JPL, Caltech
STScI
Explanation:
One of the last entries in
Charles Messier's
famous catalog, big, beautiful spiral galaxy M101 is
definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was
also one of the original spiral nebulae
observed with Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
In contrast,
this multiwavelength view
of the large
island universe
is a composite of images recorded by space-based telescopes in the
21st century.
Color coded from X-rays to infrared
wavelengths (high to low energies),
the image data was taken from the
Chandra X-ray Observatory (purple), the
Galaxy Evolution Explorer ( blue),
Hubble Space Telescope(yellow), and the
Spitzer Space Telescope(red).
While the X-ray data trace the location of multimillion degree gas
around M101's exploded stars and neutron star and black hole binary
star systems, the lower energy data follow the
stars and dust that define M101's grand spiral arms.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
(
Editor's Note: Original APOD retracted on January 25.)
A Dark Sand Dune on Mars
Image Credit:
NASA/JPL-Caltech
Explanation:
What is that dark sand dune doing on Mars?
NASA's robotic
rover Curiosity
has been studying it to find out, making this the
first-ever up-close investigation
of an active sand dune on another world.
Named
Namib Dune,
the dark sand mound stands about 4 meters tall and,
along with the other
Bagnold
Dunes, is located on the northwestern flank of
Mount Sharp.
The
featured image
was taken last month and
horizontally compressed here for comprehensibility.
Wind is causing the
dune to advance
about one meter a year across the light bedrock underneath, and
wind-blown sand is visible on the left.
Part of the Curiosity rover itself is visible on the lower right.
Just in the past few days,
Curiosity scooped up some of the dark sand for a detailed analysis.
After further exploration of the
Bagnold Dunes,
Curiosity is scheduled to continue its trek up the 5-kilometer tall
Mount Sharp, the central peak in the
large crater where the car-sized rover landed.
Proxima Centauri: The Closest Star
Image Credit:
ESA/Hubble &
NASA
Explanation:
Does the closest star to our Sun have planets?
No one is sure -- but you can now
follow frequent updates of a
new search
that is taking place during the first few months of this year.
The closest star,
Proxima Centauri, is the
nearest member of the
Alpha Centauri star system.
Light takes only 4.24 years to reach us from
Proxima Centauri.
This
small red star, captured in the center of the
featured image by the
Hubble Space Telescope,
is so faint that it was only
discovered in 1915 and is only visible through a telescope.
Telescope-created X-shaped
diffraction spikes surround Proxima Centauri,
while several stars further out in our
Milky Way Galaxy are visible in the background.
The brightest star in the
Alpha Centauri system is
quite similar to our Sun,
has been known as long as recorded history, and is the third
brightest star in the night sky.
The
Alpha Centauri system is primarily visible from
Earth's Southern Hemisphere.
Starting last week, the
European Southern Observatory's
Pale Red Dot project
began investigating slight changes in
Proxima Centauri
to see if they result from a planet -- possibly an Earth-sized planet.
Although unlikely, were a
modern civilization found living on a planet orbiting
Proxima Centauri,
its proximity makes it a reasonable possibility that humanity could
communicate with them.
The Galactic Center in Infrared
Image Credit:
2MASS Project,
UMass,
IPAC/Caltech,
NSF,
NASA
Explanation:
The center of our Galaxy is a busy place.
In
visible light,
much of the
Galactic Center
is obscured by opaque
dust.
In
infrared light, however, dust glows more and obscures less,
allowing nearly one million stars to be recorded in the
featured photograph.
The
Galactic Center
itself appears
on the left and is located about 30,000
light years away towards the constellation of the Archer (
Sagittarius).
The
Galactic Plane of our
Milky Way Galaxy, the plane in which the
Sun orbits,
is identifiable by the
dark diagonal dust lane.
The absorbing
dust grains are created in the atmospheres of
cool
red-giant stars and grow in
molecular clouds.
The region directly surrounding the
Galactic Center glows brightly in
radio and
high-energy radiation,
and is thought to house a large
black hole.
The View Toward M106
Image Credit &
Copyright:
Fabian Neyer
Explanation:
A big, bright, beautiful
spiral, Messier 106 is at the center of this
galaxy filled cosmic vista.
The two degree wide
telescopic field
of view looks toward the well-trained constellation
Canes Venatici, near the handle of the Big Dipper.
Also known as NGC 4258, M106 is about 80,000 light-years across and
23.5 million light-years away, the largest member of the
Canes II
galaxy group.
For a far away galaxy, the distance to M106 is well-known
in part because it can be
directly measured
by tracking this galaxy's remarkable maser, or microwave laser emission.
Very rare but naturally occuring, the
maser
emission is produced
by water molecules in molecular clouds orbiting its
active
galactic nucleus.
Another prominent spiral galaxy on the scene, viewed nearly
edge-on,
is NGC 4217 below and right of M106.
The distance to NGC 4217 is much less well-known, estimated
to be about 60 million light-years.
Source -
NASA
