Charon: Moon of Pluto
Image Credit:
NASA,
Johns Hopkins Univ./APL,
Southwest Research Institute
Explanation:
A darkened and mysterious north polar region
informally known as
Mordor Macula caps this premier high-resolution
portrait
of Charon, Pluto's largest moon.
Captured by New Horizons near its closest
approach on July 14, the image data was transmitted
to Earth on September 21.
The combined blue, red,
and infrared data is processed to enhance colors,
following variations in surface properties
with a resolution of about 2.9 kilometers (1.8 miles).
In fact, Charon is 1,214 kilometers (754 miles) across,
about 1/10th the size of planet Earth but a whopping 1/2 the diameter of
Pluto
itself.
That makes it the largest satellite relative to its planet
in the solar system.
This remarkable image of Charon's Pluto-facing hemisphere
shows a clearer view of an apparently
moon-girdling belt of
fractures and canyons that seems to
separate smooth southern plains from varied northern terrain.
Eclipsed in Southern Skies
Image Credit &
Copyright:
Yuri Beletsky
(Carnegie
Las Campanas Observatory)
Explanation:
This stunning panorama in southern skies was recorded
on the colorful night of September 27/28 from
Carnegie Las Campanas Observatory.
A diffuse glow and dark rifts of the central
Milky Way hang over domes of the twin 6.5 meter
Magellan telescopes.
But most eye-catching is the deep red glow of the Moon.
Immersed in Earth's shadow during the
much anticipated
perigee-total-lunar eclipse, the Moon's surface reflects the light of
sunsets and sunrises scattered and refracted into the planet's
cone-shaped umbra.
Along with the dramatic hue of the eclipsed Moon, other
colors of that night captured by the sensitive digital camera
include the red and green shades of atmospheric airglow.
Viewers can also spot the Andromeda Galaxy below the
Moon, seen as a tiny smudge through the
reddish airglow and
lights along the horizon.
The Magellanic Clouds, satellite galaxies of the Milky Way, join
in at the far left of
the full
panorama frame.
Seasonal Streaks Point to Recent Flowing Water on Mars
Image Credit:
NASA,
JPL,
U. Arizona
Explanation:
What creates these changing streaks on Mars?
Called
Recurring Slope Linea (RSL), these dark features start on the slopes of
hills and craters but don't usually extend to the bottom.
What's even more unusual is that
these streaks appear to change with the season,
appearing fresh and growing during warm weather and disappearing during the winter.
After
much study, including a
recent chemical analyses, a leading hypothesis has emerged that these streaks are likely created by
new occurrences
of liquid salty water that evaporates as it flows.
The source for the briny
water is still unclear, with two
possibilities being condensation from the Martian atmosphere and underground reservoirs.
An exciting inference is that if these
briny flows are not too salty, they may be able to support
microbial life on Mars even today.
The featured image of a hill inside
Horowitz Crater was investigated by instruments aboard the robotic
Mars Reconnaissance Orbiter
that has been returning data from Mars since 2006.
Supermoon Total Lunar Eclipse and Lightning Storm
Image Credit & Copyright:
Jose Antonio Hervás
Explanation:
What's more rare than a supermoon total lunar eclipse?
How about a supermoon total lunar eclipse over a lightning storm.
Such an electrifying sequence was captured yesterday from
Ibiza, an island in southeastern
Spain.
After planning the location for beauty, and the timing to capture the entire eclipse sequence,
the only thing that had to cooperate for this astrophotographer to capture a
memorable eclipse sequence
was the weather.
What looked to be a
bother on the
horizon, though, turned out to be a
blessing.
The
composite picture features over
200 digitally combined images from the same location over the course of a night.
The full moon is seen setting as it
faded to
red in Earth's shadow and then returned to normal.
The fortuitous lightning is seen reflected in the Mediterranean to the right of the 400-meter tall rocky island of
Es Vedra.
Although the next total eclipse of a large and bright supermoon will occur in 2033, the
next total eclipse
of any full moon will occur in January 2018 and be best
visible from eastern Asia and Australia.
Total Lunar Eclipse over Waterton Lake
Image Credit & Copyright:
Yuichi Takasaka /
TWAN /
www.blue-moon.ca
Explanation:
Recorded in 2014 April, this
total
lunar eclipse sequence looks south down icy Waterton Lake from the
Waterton
Lakes National Park in Alberta, Canada, planet Earth.
The most distant horizon includes peaks in
Glacier National Park,
USA.
An exposure every 10 minutes captured the Moon's position and
eclipse phase, as it arced, left to right, above the rugged skyline
and Waterton town lights.
In fact, the sequence effectively measures the roughly 80 minute
duration
of the total phase of the
eclipse.
Around 270 BC, the Greek astronomer
Aristarchus
also measured the duration of lunar eclipses - though probably without
the benefit of
digital clocks and cameras.
Still,
using geometry, he
devised a simple and impressively accurate way to calculate
the Moon's distance, in terms of the radius of
planet Earth,
from the eclipse duration.
This modern eclipse sequence also tracks the
successive positions of Mars,
above and right of the Moon, bright star
Spica next to the reddened
lunar disk, and Saturn to the left and below.
M31 versus M33
Image Credit &
Copyright:
Malcolm Park
(North York Astronomical Association)
Explanation:
Separated by about 14 degrees
(28
Full Moons) in planet Earth's sky,
spiral galaxies M31 at left, and M33 are both large members of
the Local
Group, along with our own Milky Way galaxy.
This narrow- and wide-angle,
multi-camera
composite finds details of spiral structure
in both, while the massive neighboring galaxies seem to be balanced
in starry fields either side of
bright
Mirach, beta star in
the constellation Andromeda.
Mirach is just 200 light-years from the Sun.
But
M31, the Andromeda Galaxy,
is really 2.5 million light-years distant and
M33, the Triangulum Galaxy, is also about
3 million light years away.
Although they look far apart,
M31 and M33 are engaged in a gravitational struggle.
In fact, radio astronomers have
found indications of
a bridge of neutral hydrogen gas that could connect the two,
evidence of a closer encounter in the past.
Based on measurements, gravitational
simulations currently
predict that the Milky Way, M31, and M33
will all undergo mutual close encounters and potentially
mergers, billions of years
in the future.
Pluto's Snakeskin Terrain
Image Credit:
NASA,
Johns Hopkins Univ./APL,
Southwest Research Institute
Explanation:
A
mountainous region informally known as Tartarus Dorsa sprawls
some 530 kilometers (330 miles) across this
Plutonian landscape.
Recently downloaded
from New Horizons,
it combines blue,
red, and infrared image data in an extended color view
captured near the spacecraft's close approach to Pluto on July 14.
Shadows near the terminator, the line between Pluto's dim day and night,
emphasize a rough, scaly
texture.
The stunning image resolves details
on the distant world about 1.3 kilometers (0.8 miles) across.
Refering to a
part
of Hades in ancient Greek mythology,
Tartarus Dorsa borders Tombaugh Regio
to the east.
LDN 988 and Friends
Image Credit &
Copyright:
Rafael
Rodríguez Morales
Explanation:
Stars
are forming in dark, dusty molecular cloud LDN 988.
Seen near picture center
some 2,000 light-years distant,
LDN 988 and other nearby dark nebulae were cataloged
by
Beverly T. Lynds
in 1962 using Palomar Observatory Sky Survey plates.
Narrowband and near-infrared
explorations of the dark
nebula reveal energetic shocks and outflows light-years across
associated with dozens of newborn stars.
But in this sharp optical telescopic view,
the irregular outlines of
LDN 988
and friends look like dancing stick figures eclipsing
the rich starfields of the constellation Cygnus.
From dark sky sites the region can be
identified
by eye alone.
It's part of the Great Rift of dark nebulae along the
plane of the Milky Way galaxy known as
the
Northern Coalsack.
Antarctic Analemma
Image Credit & Copyright:
Adrianos Golemis
Explanation:
Does the Sun return to the same spot on the sky every day? No.
A better and more visual answer to that question is an
analemma,
a composite image taken from the same spot at the same time over the course of a year.
The featured weekly analemma was taken despite
cold temperatures and
high winds near the
Concordia Station in Antarctica.
The position of the Sun at 4 pm was captured on multiple days in the digital composite image,
believed to be the first
analemma constructed from
Antarctica.
The reason the image only shows the Sun from September to
March is because the Sun was below the horizon for much of the rest of the year.
In fact, today being an
equinox, the Sun rises today at the
South Pole
after a six month absence and won't set again until the next
equinox in March, baring
large atmospheric refraction effects.
Conversely, today the Sun
sets at the
North Pole
after half a year of continuous daylight.
For all of the Earth in between, though, the
equinox means that today will have a nighttime and daytime that are both 12 hours long.
Milky Way over Bosque Alegre Station in Argentina
Image Credit & Copyright:
Sebastián D' Alessandro;
Rollover Annotation: Judy Schmidt
Explanation:
What are those streaks of light in the sky?
First and foremost, the arching structure is the central band of our
Milky Way galaxy.
Visible in
this galactic band
are millions of distant stars mixed with numerous lanes of dark dust.
Harder to discern is a nearly vertical beam of light rising from the horizon, just to the right of the image center.
This beam is
zodiacal light,
sunlight scattered by dust in our Solar System that may be
surprisingly prominent just after sunset or just before sunrise.
In the foreground are several telescopes of the
Bosque Alegre Astrophysical Station
of the
National University of Cordoba in
Argentina.
The station schedules
weekend tours and conducts research into the nature of
many astronomical objects including
comets,
active galaxies, and
clusters of galaxies.
The featured image was taken early this month.
Spiral Galaxy M96 from Hubble
Image Credit:
ESA/Hubble &
NASA and the
LEGUS Team;
Acknowledgement:
R. Gendler
Explanation:
Dust lanes seem to swirl around the core of
Messier 96 in this
colorful,
detailed portrait of the center of a beautiful
island universe.
Of course M96 is a
spiral galaxy, and counting the faint arms extending
beyond the brighter central region, it spans 100 thousand
light-years or so, making it about the size of our own
Milky Way.
M96, also known as
NGC 3368,
is known to be about 35 million light-years distant and a dominant
member of the
Leo I galaxy group.
The
featured image was taken by the
Hubble Space Telescope.
The reason for
M96's asymmetry is unclear -- it could have arisen from gravitational interactions with other Leo I
group galaxies, but the lack of an intra-group diffuse glow seems to indicate
few recent interactions.
Galaxies far in the background can be found by
examining the edges of the picture.
Source -
NASA
