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Barred Spiral Galaxy NGC 1300
http://antwrp.gsfc.nasa.gov/apod/image/0806/ngc1300_hst.jpg
Submitted by APOD
5 months, 2 days, 5 hours ago
Big, beautiful, barred spiral galaxy
NGC 1300 lies some 70 million
light-years away on the banks of the
constellation
Eridanus.
This Hubble Space Telescope
composite view of the gorgeous island universe is one of the
largest Hubble images ever made of a complete
galaxy.
NGC 1300
spans over 100,000 light-years and the
Hubble
image reveals striking details of the galaxy's dominant
central bar and majestic spiral arms.
In fact, on close inspection
the nucleus of this classic barred
spiral itself shows a remarkable region of
spiral structure
about 3,000 light-years across.
Unlike other
spiral galaxies,
including our own Milky Way, NGC 1300
is not presently known to have a massive
central black hole.
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Vanishing Act
http://antwrp.gsfc.nasa.gov/apod/image/0806/sol020_024_chang...
Submitted by APOD
5 months, 3 days, 5 hours ago
Compare these two close-up
pictures taken on sol 20 (left) and sol 24 of
a trench dug in the Martian surface by NASA's
Phoenix Lander.
Those sols of the Phoenix Mission
(a sol is a Martian day),
correspond to June 15 and 18 on planet Earth.
Light-colored, dice-sized chunks, visible in the lower left shadow region
of the trench in the sol 20 image
have vanished by sol 24 --
a strong indication that the chunks were ice uncovered
by digging the shallow trench.
The vanishing act likely demonstrates the
sublimation of ice in the
trench, a process similar to evaporation, in which the ice went directly
from solid to gas after it was
exposed to sunlight and the thin, dry
Martian atmosphere.
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Solstice Moonrise, Cape Sounion
http://antwrp.gsfc.nasa.gov/apod/image/0806/solmoon_ayiomami...
Submitted by APOD
5 months, 4 days, 5 hours ago
Today's solstice marks the northernmost point of
the Sun's annual
motion through planet
Earth's sky and the
astronomical beginning of the northern
hemisphere's summer.
But only two days ago, the Full Moon nearest the solstice
rose close to the ecliptic plane
opposite the Sun, near its southernmost point for the year.
Astronomer Anthony Ayiomamitis recorded
this
dramatic picture of the solstice Full Moon
rising above
Cape Sounion,
Greece.
The twenty-four hundred year old
Temple
of Poseidon lies in
the foreground,
also
visible to sailors on
the Aegean Sea.
In this well-planned single exposure, a telescopic lens
makes the Moon loom large, but even without
optical aid casual skygazers often find
the Full Moon looking astonishingly large when
seen near the horizon.
That powerful visual effect is known as the
Moon Illusion.
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The Star Streams of NGC 5907
http://antwrp.gsfc.nasa.gov/apod/image/0806/ngc5907_gabany_r...
Submitted by APOD
5 months, 5 days, 5 hours ago
Grand tidal streams of stars seem to surround galaxy
NGC 5907.
The arcing structures form tenuous loops extending more than 150,000
light-years from the narrow, edge-on spiral, also known as the
Splinter
or Knife Edge Galaxy.
Recorded only in very deep exposures, the streams likely represent
the
ghostly trail of a dwarf galaxy -- debris left along the
orbit of a
smaller satellite galaxy that was gradually
torn
apart and
merged
with NGC 5907 over four billion years ago.
Ultimately this remarkable discovery image, from a small robotic
observatory in New Mexico, supports the cosmological
scenario in
which large spiral galaxies,
including
our own Milky Way, were
formed by the accretion of smaller ones.
NGC 5907 lies about 40 million light-years distant in the northern
constellation
Draco.
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Pyramid Ice Crystal Halos Over Finland
http://antwrp.gsfc.nasa.gov/apod/image/0806/skylens_nyman.jp...
Submitted by APOD
5 months, 6 days, 5 hours ago
What if the atmosphere above you became one gigantic lens?
This actually happens when a nearly transparent sheet of
pyramid shaped ice crystals
falls from the sky in a common orientation.
These ice-crystals act together like millions of miniature ice mirrors, with external and internal reflections from different faces creating
arcs and halos of different radii.
An amazing display of pyramid ice crystal halos was
captured
on June 5 above
Tampere,
Finland.
Visible above are
very usual sun halos
of 9, 18, 20, and 23, and 24 degrees.
In contrast, thin and flat falling ice crystals will
produce a halo of
22 degrees only.
The high clouds containing the ice crystals are faintly visible, as are some
sundogs.
The usual Sun image was covered behind a light post,
and the above image was significantly digitally sharpened.
It is not currently known how large areas of nearly uniform
pyramidal ice crystals form.
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Eta Carinae and the Homunculus Nebula
http://antwrp.gsfc.nasa.gov/apod/image/0806/etacar2_hst.jpg
Submitted by APOD
5 months, 1 week, 5 hours ago
How did the star Eta Carinae create this unusual nebula?
No one knows for sure.
About 165 years ago, the southern star
Eta Carinae
mysteriously became the second
brightest star in the night sky.
In 20 years, after ejecting more mass than our Sun, Eta Car unexpected faded.
This outburst appears to have created the
Homunculus Nebula,
pictured above in a composite image from the
Hubble Space Telescope
taken last decade.
Visible in the
above image
center is purple-tinted light reflected from the violent star Eta Carinae itself.
Surrounding this star are expanding lobes of gas laced with filaments of dark
dust.
Jets bisect the lobes emanating from the central star.
Surrounding these lobes are
red-tinted debris
captured only by its glow in a narrow band of red light.
This debris is expanding most quickly of all, and includes streaming
whiskers and
bow shocks caused by collisions with
previously existing material.
Eta Car still undergoes
unexpected outbursts,
and its high mass and volatility make it a candidate to explode in a
spectacular supernova
sometime in the next few million years.
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Inside the Coma Cluster of Galaxies
http://antwrp.gsfc.nasa.gov/apod/image/0806/coma_hst.jpg
Submitted by APOD
5 months, 1 week, 1 day, 5 hours ago
Almost every object in the above photograph is a galaxy.
The Coma Cluster of Galaxies
pictured above
is one of the densest
clusters known - it contains thousands of
galaxies.
Each of these galaxies houses billions of stars -
just as our own Milky Way Galaxy does.
Although nearby when compared to most other
clusters,
light from the Coma Cluster
still takes hundreds of millions of years to reach us.
In fact, the
Coma Cluster is so big it takes light
millions of years just to go from one side to the other!
The above mosaic of images of a small portion of
Coma was taken in unprecedented detail by the
Hubble Space Telescope
to investigate how galaxies in rich clusters form and evolve.
Most galaxies in Coma and other clusters are
ellipticals, although some
imaged here are clearly spirals.
The spiral galaxy on the upper left of the
above image can also be found as one of the bluer galaxies on the upper left of
this wider field image.
In the background thousands of unrelated galaxies are
visible far across the universe.
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Phoenix Digs for Clues on Mars
http://antwrp.gsfc.nasa.gov/apod/image/0806/armpanels_phoeni...
Submitted by APOD
5 months, 1 week, 2 days, 5 hours ago
What's a good recipe for preparing Martian soil?
Start by filling your robot's scoop a bit less than half way.
Next, dump your Martian soil into one of your
TEGA
ovens, being sure to
watch out for clumping.
Then, slowly increase the temperature to over 1000 degrees
Celsius over several days.
Keep checking to see when your soil becomes
vaporized.
Finally, your Martian soil is not ready for eating, but rather
sniffing
The above technique is being used by the
Phoenix Lander that
arrived on Mars
three weeks ago.
Data from the first batch of baked soil should be available in a few days.
Pictured above, a circular array of the Phoenix Lander's
solar panels
are visible on the left, while a scoop partly filled with Martian soil is visible on the right.
The robotic Phoenix Lander
will spend much of the next three months digging, scooping, baking, sniffing, zapping, dissolving, and magnifying bits of Mars to help neighboring
Earthlings learn more about the
hydrologic and biologic possibilities of the
sometimes mysterious red planet.
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M51 Hubble Remix
http://antwrp.gsfc.nasa.gov/apod/image/0806/M51HST-GendlerS_...
Submitted by APOD
5 months, 1 week, 3 days, 5 hours ago
The 51st entry
in Charles Messier's famous catalog is perhaps the original
spiral
nebula - a large galaxy with a
well defined spiral structure also cataloged as NGC 5194.
Over 60,000 light-years across, M51's spiral arms and dust lanes
clearly sweep in front of its companion galaxy (right),
NGC 5195.
Image data from the Hubble's
Advanced Camera for Surveys has been
reprocessed to produce
this
alternative portrait of the
well-known interacting galaxy pair.
The processing has further sharpened details and enhanced color
and contrast in otherwise faint areas, bringing out
dust lanes and extended streams that cross the small companion, along
with features in the surroundings and core of M51 itself.
The pair are
about 31 million light-years distant.
Not far on the sky from the handle of the
Big Dipper,
they officially lie within the boundaries of the small constellation
Canes Venatici.
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At Last, GLAST
http://antwrp.gsfc.nasa.gov/apod/image/0806/glast08pd1642_c8...
Submitted by APOD
5 months, 1 week, 4 days, 5 hours ago
Rising through a billowing cloud of smoke,
this
Delta II rocket
left Cape Canaveral Air Force Station's launch pad 17-B
Wednesday at 12:05 pm EDT.
Snug
in the payload section was GLAST, the
Gamma-ray
Large Area Space Telescope, now in orbit around planet Earth.
GLAST's
detector technology was developed for use in terrestrial
particle accelerators.
But from orbit,
GLAST can study
gamma-rays from
extreme environments in our own Milky Way galaxy, as well as
supermassive black holes at the centers of distant
active galaxies,
and the sources of powerful
gamma-ray bursts.
Those cosmic accelerators achieve energies not attainable in earthbound
laboratories.
GLAST also has the sensitivity to search
for signatures of new physics
in the relatively
unexplored high-energy gamma-ray regime.
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