Explanation:
A mysterious formation known as
Devils
Tower rises into
the dark above northeastern Wyoming's prairie landscape in this 16
frame panoramic view.
Seen against the night sky's thin, pale clouds and eerie green
airglow, star clusters and nebulae
of the Milky Way arc toward the galaxy's
central realm
at right.
Of course the scene contains the Milky Way's own
haunting and grisly visages
of
halloween, including
ghosts,
a flaming
skull,
a glowing eye and
a witch's broom.
To find them, slide your cursor over the picture or just
follow this link,
if you dare.
And have a safe and Happy Halloween!
Explanation:
When orbiting Saturn, be sure to watch for breathtaking superpositions of moons and rings.
One such picturesque vista was visible recently to the robot
Cassini spacecraft
now orbiting Saturn.
In 2006 April, Cassini
captured Saturn's
A and
F
rings stretching in front of
cloud-shrouded Titan.
Near the rings and appearing just above Titan was
Epimetheus, a moon which orbits just outside the
F ring.
The dark space in the
A ring is called the
Encke Gap, although several thin knotted ringlets and even the small moon
Pan orbit there.
Plane, Clouds, Moon, Spots, Sun
Image Credit & Copyright: Doyle Slifer
Image Credit & Copyright: Doyle Slifer
Explanation:
What's that in front of the Sun?
The closest object is an
airplane, visible just below the Sun's center and caught purely by chance.
Next out are numerous clouds in
Earth's atmosphere, creating a series of darkened horizontal streaks.
Farther out is Earth's Moon, seen as the large dark circular bite on the upper right.
Just above the airplane and just below the Sun's surface are sunspots.
The main sunspot group captured here,
AR 2192, is one of the largest ever recorded and has been
crackling and bursting with
flares since it came around the edge of the Sun early last week.
Taken last Thursday, this show of solar silhouettes was unfortunately short-lived.
Within a few seconds the plane flew away.
Within a few minutes the clouds drifted off.
Within a few hours the
partial solar eclipse of the Sun by the Moon was over.
Only the sunspot group remains, but within a few more days even AR 2192 will disappear around the edge of the Sun.
Fortunately, when it comes to the Sun, even
unexpected alignments are
surprisingly frequent.
Explanation:
Why would Mars appear to move backwards?
Most of the time, the apparent motion of
Mars in
Earth's sky is in one direction,
slow but steady in front of the far distant stars.
About every two years, however, the
Earth passes Mars
as they orbit around the Sun.
During the most recent such pass starting late last year,
Mars as usual, loomed
large and bright.
Also during this time, Mars appeared to move backwards in the sky,
a phenomenon called
retrograde motion.
Featured here is a series of images digitally stacked
so that all of the stars coincide.
Here, Mars appears to
trace out a narrow loop in the sky.
At the center of the loop, Earth passed Mars and the
retrograde motion was the highest.
Retrograde motion can also be seen for other
Solar System planets.
Iridescent Cloud Edge Over Colorado
Image Credit & Copyright: Phil Plait (Bad Astronomy Blog, Slate)
Image Credit & Copyright: Phil Plait (Bad Astronomy Blog, Slate)
Explanation:
Sometimes your eclipse viewing goes bad in an interesting way.
While watching and photographing
last Thursday's
partial solar eclipse, a
popular astronomy blogger
suffered through long periods of
clouds blocking the Sun.
Unexpectedly, however, a nearby cloud began to show a rare effect:
iridescence.
Frequently part of a more familiar solar
corona effect,
iridescence
is the diffraction of sunlight around a thin screen of
nearly uniformly-sized
water droplets.
Different colors
of the sunlight become deflected by slightly
different angles
and so come to the observer from slightly different directions.
This display,
featured here, was quite bright and exhibited an unusually broad range of colors.
On the right, the
contrails of an airplane are also visible.
Explanation:
Frightening
forms and scary faces are a mark of the Halloween season.
They also haunt
this
cosmic close-up of the eastern Veil Nebula.
The Veil Nebula itself is a
large supernova remnant, the expanding
debris cloud from the death explosion of a massive star.
While the Veil is roughly circular in shape and covers nearly 3 degrees
on the sky in the constellation Cygnus, this portion of the eastern
Veil spans only 1/2 degree, about the apparent size
of the Moon.
That translates to 12 light-years at the Veil's
estimated distance, a reassuring 1,400 light-years from planet Earth.
In the composite of image data recorded through broad and
narrow band filters,
emission from hydrogen atoms in the remnant is shown in red with strong
emission from oxygen atoms in blue-green hues.
Of course, in the western part of the Veil lies another
seasonal apparition,
the Witch's Broom.
Explanation:
October 31, 1938 was the day after Martians encountered planet Earth,
and everything was calm.
Reports of the invasion were revealed to be part of a
Halloween radio drama, the now famous broadcast
based on H.G. Wells' scifi novel
War of the Worlds.
On Mars October 20, 2014 was calm too,
the day after its close encounter with
Comet
Siding Spring.
Not a hoax, this comet really did come within 86,700 miles or so of
Mars, about 1/3 the Earth-Moon distance.
Earth's
spacecraft and rovers in Mars orbit and on the surface
reported no ill effects though, and
had a ringside seat as a visitor from the
outer solar system passed by.
Spanning over 2 degrees against stars of the constellation Ophiuchus,
this colorful
telescopic snapshot captures our view of Mars on the day after.
Bluish star
51 Ophiuchi is at the upper right and
the comet is just emerging from the Red Planet's bright glare.
In Green Company: Aurora over Norway
Image Credit & Copyright: Max Rive
Image Credit & Copyright: Max Rive
Explanation:
Raise your arms if you see an aurora.
With those instructions, two nights went by with, well, clouds -- mostly.
On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a
spectacular auroral display.
Arms went high in the air, patience and experience paid off,
and the amazing
featured image was captured.
The setting is a summit of the
Austnesfjorden
fjord close to the town of
Svolvear on the
Lofoten islands in northern Norway.
The time was early March.
Our Sun has been producing an abundance of
picturesque aurora of late as it is near the time of its
maximum surface activity in its
11-year magnetic cycle.
Explanation:
Described at times as a big
blue marble,
from some vantage points Earth looks more like a small blue marble.
Such was the case in this
iconic image of the
Earth and Moon system taken by the
Chang'e 5-T1 mission last week.
The Moon appears larger than the Earth because it was much closer to the spacecraft's camera.
Displaying much of a surface
usually hidden from
Earth, the Moon appears dark and gray when compared to the more reflective and
colorful planet that it orbits.
The robotic
Chang'e 5-T1 spacecraft,
predominantly on an
engineering test mission,
rounded the Moon last Tuesday
returned to Earth on Friday.
Explanation:
Why is there a bright line on the sky?
What is pictured above is actually a disk
galaxy being seen almost perfectly edge on.
The image from the
Hubble Space Telescope
is a spectacular visual reminder of just how
thin
disk
galaxies can be.
NGC 4762, a galaxy in the nearby
Virgo Cluster of Galaxies,
is so thin that it is actually
difficult to determine what type of disk galaxy it is.
Its lack of a visible dust lane indicates that it is a low-dust
lenticular galaxy, although it is still possible that a view from on top would reveal spiral structure.
The unusual stellar line spans about 100,000
light years from end to end.
Near NGC 4762's center is a slight bulge of stars, while
many background galaxies
are visible far in the distance.
Galaxies that appear this thin are rare mostly because our Earth must reside (nearly) in the extrapolated
planes of their thin galactic disks.
Galaxies that actually are this thin are relatively common -- for example our own
Milky Way Galaxy is thought to be about this
thin.
All images' Source - NASA
