Enhanced Color Caloris
Image Credit:
NASA,
Johns Hopkins Univ. APL,
Arizona State U., CIW
Explanation:
The sprawling Caloris basin
on Mercury
is one of the solar system's largest
impact basins,
created during the early history of the solar system by the impact of
a large asteroid-sized body.
The multi-featured,
fractured basin spans about 1,500 kilometers in this
enhanced
color mosaic based on image data from the Mercury-orbiting
MESSENGER spacecraft.
Mercury's youngest large impact basin,
Caloris was subsequently filled
in by lavas that appear orange in the mosaic.
Craters made after the flooding
have excavated material from beneath the surface lavas.
Seen as contrasting blue hues, they likely offer a glimpse of
the original basin floor material.
Analysis of these craters suggests the thickness
of the covering volcanic lava to be 2.5-3.5 kilometers.
Orange splotches around the basin's perimeter are thought to be
volcanic vents.
Orion Spring
Image Credit &
Copyright:
Bill Dickinson
Explanation:
As spring comes to planet Earth's northern hemisphere, familiar winter
constellation Orion sets in early evening skies and budding trees
frame
the Hunter's stars.
The yellowish hue of cool red supergiant
Alpha
Orionis,
the great star Betelgeuse, mingles with the branches at the top of
this
colorful skyscape.
Orion's alpha star is joined on the far right by
Alpha
Tauri.
Also known as Aldebaran and also a giant star cooler than the Sun,
it shines with a yellow light at the head of Taurus, the Bull.
Contrasting blue supergiant Rigel,
Beta
Orionis,
is Orion's other dominant star though, and marks
the Hunter's foot below center.
Of course, the sword of Orion hangs from the Hunter's three blue belt
stars near picture center, but the middle star in the sword is not a
star at all.
A slightly fuzzy pinkish glow hints at its true nature, a
nearby
stellar nursery
visible to the unaided eye known as
the Orion Nebula.
NGC 602 in the Flying Lizard Nebula
Image Credit &
Copyright:
Don Goldman
Explanation:
Near the outskirts of the
Small Magellanic Cloud,
a satellite galaxy some 200 thousand light-years distant,
lies 5 million year
young
star cluster NGC 602.
Surrounded by natal gas and dust,
NGC 602
is just below center in this
telescopic field of view with the angular size of
the Full Moon on the sky.
The cluster itself is about 200 light-years in diameter.
Glowing interior ridges and swept back shapes strongly suggest that
energetic radiation and shock waves from NGC 602's massive
young stars have eroded the dusty material and triggered a
progression
of star formation moving away from the cluster's center.
Of course, the more extended wings of emission in the
region suggest a popular name for
the complex cosmic environment,
The
Flying Lizard Nebula.
Stars at the Galactic Center
Image Credit:
Susan Stolovy
(SSC/Caltech)
et al.,
JPL-Caltech,
NASA
Explanation:
The center
of our Milky Way Galaxy
is hidden
from the prying eyes of optical telescopes by clouds of
obscuring dust and gas.
But in
this stunning vista, the Spitzer Space Telescope's
infrared cameras, penetrate
much of the
dust revealing the stars of the crowded
galactic center
region.
A mosaic of many smaller snapshots, the detailed,
false-color image shows
older, cool stars in bluish hues.
Reddish glowing dust clouds are associated with
young, hot stars in stellar nurseries.
The very center of the Milky Way was only
recently found capable of forming
newborn stars.
The
galactic center
lies some 26,000 light-years away, toward the constellation
Sagittarius.
At that distance, this picture spans about 900 light-years.
Along the Cygnus Wall
Image Credit &
Copyright:
Jimmy Walker
Explanation:
The W-shaped ridge of emission featured in
this
vivid skyscape is known as the Cygnus Wall.
Part of a larger
emission
nebula with a distinctive outline popularly called
The North America Nebula,
the cosmic ridge spans about 20 light-years.
Constructed using narrowband data to highlight the telltale
reddish glow from
ionized hydrogen
atoms recombining with electrons, the two frame mosaic image follows an
ionization front with fine details of dark, dusty forms in silhouette.
Sculpted
by energetic radiation from the region's young, hot, massive stars,
the dark shapes inhabiting the view are clouds of cool gas and dust
with stars likely forming within.
The North America Nebula itself, NGC 7000,
is about 1,500 light-years away.
The Great Wall by Moonlight
Image Credit &
Copyright:
Francis Audet
Explanation:
Last Friday, an almost
Full Moon rose as the Sun set,
over this mountainous landscape north of Beijing, China.
Also near apogee,
the farthest point in its elliptical orbit around
planet Earth, it was this year's smallest and faintest Full Moon.
The Jiankou section of the
Great Wall
of China meanders through the
scene, the ancient Great Wall itself the subject of an
older-than-the-space-age myth
that it would be visible to the eye when
standing on the lunar surface.
But
even from low Earth orbit,
the large scale artifact of human
civilization is very difficult to identify.
At its farthest from our fair planet, the Moon shines brightly
in the twilight sky though, posing in the faint, pinkish band known as
the antitwilight arch or the
belt of Venus.
A Dust Devil on Mars
Image Credit:
HiRISE,
MRO,
LPL (U. Arizona),
NASA
Explanation:
It was late in the northern martian spring
when the
HiRISE camera onboard the
Mars Reconnaissance Orbiter spied
this local denizen.
Tracking across the flat, dust-covered
Amazonis Planitia in 2012,
the core of
this whirling dust devil is about 140 meters in diameter.
Lofting dust into the thin
martian
atmosphere, its plume
reaches about 20 kilometers above the surface.
Common to
this region of
Mars, dust
devils occur as the surface is heated by the Sun,
generating warm, rising air currents that begin to rotate.
Tangential
wind speeds of up to 110 kilometers per hour are reported for
dust devils in other
HiRISE images.
The Clouds of Orion the Hunter
Image Credit & Copyright:
Rogelio
Bernal Andreo
Explanation:
Cradled in cosmic dust and glowing hydrogen,
stellar
nurseries in Orion the
Hunter
lie at
the edge of giant molecular clouds some 1,500 light-years away.
Spanning about 30 degrees,
this breath-taking vista
stretches across the well-known constellation from
head to toe (left to right) and beyond.
At 1,500
light years away, the
Great Orion
Nebula is the closest large star forming region, here visible
just right and below center.
To its left are the
Horsehead Nebula,
M78, and
Orion's belt stars.
Sliding your cursor over the picture will also find
red giant
Betelgeuse at the hunter's shoulder,
bright blue
Rigel at his foot,
the
Witch Head Nebula above -- and illuminated by -- Rigel,
and the glowing Lambda Orionis
(
Meissa) nebula on the left, near Orion's head.
Of course, the Orion Nebula and bright stars are
easy to see with the
unaided eye, but dust clouds and emission from the extensive interstellar
gas in this
nebula-rich complex,
are too faint and much harder to record.
In this mosaic of broadband telescopic images, additional image
data acquired with a narrow
hydrogen alpha filter was used to
bring out the pervasive tendrils of energized
atomic hydrogen gas like in the arc of the giant
Barnard's Loop.
The Big Dipper Enhanced
Image Credit & Copyright:
VegaStar Carpentier
Explanation:
Do you see it?
This common question frequently precedes the rediscovery of one of the
most commonly recognized configurations of stars on the northern sky:
the
Big Dipper.
This grouping of stars is one of the few things that has likely been seen, and will be seen, by
every human generation.
In
this featured image, however, the stars of the
Big Dipper have been digitally enhanced --
they do not really appear this much
brighter than
nearby stars.
The image was taken earlier this month from
France.
The Big Dipper is not by itself a
constellation.
Although part of the constellation of the
Great Bear (Ursa Major), the
Big Dipper is an
asterism
that has been known by
different names
to different societies.
Five of the Big Dipper
stars are actually near each other in space and were
likely formed
at nearly the same time.
Relative stellar motions will cause the
Big Dipper to
slowly change its
apparent configuration over the next 100,000 years.
Sunshine, Earthshine
Image Credit:
Dylan O'Donnell
Explanation:
Today's date
marks an Equinox and a New Moon.
Remarkably, while the exact timing of both
geocentric
events occur within a span of only 13 hours,
the moon also reaches its new phase only 14 hours after perigee, the
closest point in its orbit.
That makes the Equinox New Moon the largest New Moon of 2015,
though hard to see since that lunar phase presents the Moon's
dark, night side to planet Earth.
Still, in
this well composed image
of a young lunar phase from late January
you can glimpse both night and day on the lunar surface,
the night side faintly illuminated by Earthshine next to the day side's
brightly sunlit crescent.
But some will see today's
Equinox New Moon in silhouette!
The Equinox Solar Eclipse will be total across stretches
of the Arctic Ocean,
visible in partial phases from Europe, northern Africa
and western Asia.
A Double Eclipse of the Sun
Image Credit & Copyright:
Thierry Legault
Explanation:
Can the Sun be eclipsed twice at the same time?
Last Friday was noteworthy because part of the Earth was treated to a rare
total eclipse of the Sun.
But also on Friday, from a
part of the Earth
that only saw part of the Sun eclipsed, a second object
appeared simultaneously in front of the Sun: the Earth-orbiting
International Space Station.
Although
space station
eclipses are very quick -- in this case only 0.6 seconds, they are
not so rare.
Capturing
this composite image took a lot of planning and a little luck,
as the photographer had to dodge a series of third objects that kept,
annoyingly, also lining up in front of the Sun:
clouds.
The
above superposed time-lapse sequence was taken from
Fregenal de la Sierra in southern
Spain.
The dark disk of the Moon dominates the lower right, while the
Sun's textured surface shows several
filaments and, over an edge, a
prominence.
Powers of Ten
Video Credit & Copyright:
Charles & Ray Eames
(Eames Office)
Explanation:
How different does the universe look on small, medium, and large scales?
The most famous short science film of its generation gives breathtaking comparisons.
That film,
Powers of Ten, originally created in the 1960s, has now been officially posted to YouTube and embedded
above.
Please click the above arrow to see the nine minute movie for yourself.
From a picnic blanket
near Chicago out past the
Virgo Cluster of Galaxies,
every ten seconds the film zooms out to show a square a factor of ten times larger on each side.
The video then reverses, zooming back in a factor of ten every two seconds and ends up inside a single proton.
The Powers of Ten
sequence is actually based on the book
Cosmic View by
Kees Boeke in 1957, as is a similar but mostly animated film
Cosmic Zoom that was also created in the late 1960s.
The changing perspectives are so
enthralling and educational that sections have been
recreated using
more modern computerized techniques, including the first few minutes of the movie
Contact, and in a short digital video called
The Known Universe created in 2010 for the
American Museum of Natural History.
Ray and husband Charles Eames, the film's creators, were known as quite visionary spirits and even invented
their own popular chair.
Source -
NASA
