Star clusters, glowing nebulae
and dark dust clouds
abound
in Cepheus, royal constellation of
the northern hemisphere.

You can follow them in amazing detail across this broad
skyscape,
a mosaic of telescopic images spanning about 17 degrees.

Beginning at the lower left, the large emission nebula
is cataloged as IC 1396.

Hundreds of light-years across and about 3,000 light-years distant,
it contains a dark, winding, tendril-shaped feature popularly known
as the Elephant’s Trunk.

Near the top middle, the bright nebula with an embedded star cluster
is NGC 7380.

At the upper right lies NGC 7635
(the Bubble Nebula) and
star cluster M52.

Put your cursor over the picture to see a labeled version
of the field.

Many of the objects highlighted have a designation from the
second version of the
Sharpless
catalog (Sh2) and the
Barnard catalog (B) of dark nebulae.

Associated with star formation, the sites are telltale markers along
the region’s complex of giant
molecular clouds.

Why are there faint rings around this spiral galaxy?

Possibly because the galaxy,
NGC 4911, is being pulled at by its neighbors as it falls into the enormous
Coma Cluster of Galaxies.

If NGC 4911 ends up like most of the galaxies in the
central Coma cluster, it will become a yellowish
elliptical galaxy,
losing not only its outer layers, but dust, gas, and its cadre of surrounding
satellite galaxies as well.

Currently, however,
this process is just beginning.

Visible in the above deep image from the
Hubble Space Telescope are NGC 4911′s bright nucleus, distorted spiral arms laced with dark dust, clusters of recently formed stars, unusual faint outer rings, dwarf companion galaxies, and even faint
globular clusters of stars.

Far in the distance many unassociated galaxies
from the early universe are visible, some even through
NGC 4911 itself.

The Coma Cluster contains over 1,000 galaxies making it among the most massive objects known.

NGC 4911 can be found to the lower left of the great cluster’s center.

They are some of the
most complex machines ever built.

From a standing start they can launch a
school-
bus
sized object up so high and moving so fast that it
won’t fall back down.

They have launched numerous revolutionary
satellites
that enable humans to
communicate across the globe,
to better
understand Earth’s atmosphere, and to
peer into the distance universe.

They are
NASA’s Space Shuttles, and NASA has recently released
large digital posters to honor them.

While the inaugural flight
was in 1981, the shuttle fleet is aging and is now
nearing retirement.

Pictured above, the space shuttle
Endeavour is shown rising
to orbit, with
patches
for each of its missions shown in a spiral.

Endeavour was named for the
HMS Endeavour,
a British research ship that explored the south Pacific Ocean in the 1700s, depicted on the lower right.

On the upper right are
panoramic windows delivered by Endeavour to the
International Space Station earlier this year.

In the background near the top is the
NGC 602 nebula as imaged by the
Hubble Space Telescope, which was serviced by Endeavour in 1993.

Posters
for
all
of
the
shuttles,
including
Atlantis,
Challenger,
Columbia,
Discovery,
Endeavour are available.

Why are these people shooting a powerful laser into the center of our Galaxy?

Fortunately, this is not meant to be the first step in a
Galactic
war.

Rather, astronomers at the
Very Large Telescope (VLT) site in
Chile
are trying to measure the distortions of
Earth’s ever changing atmosphere.

Constant imaging of high-altitude atoms excited by the laser — which appear like an
artificial star — allow astronomers to instantly
measure atmospheric blurring.

This information is fed back to a VLT telescope mirror which is then
slightly deformed to minimize this blurring.

In this case, a VLT was observing
our Galaxy’s center,
and so Earth’s atmospheric blurring in that direction was needed.

As for inter-galaxy warfare,
when viewed from
our Galaxy’s center,
no casualties are expected.

In fact, the light from this
powerful laser would combine with light from our Sun to together appear
only as bright as a faint and distant star.

In the center of a swirling whirlpool of hot gas
is likely a beast that has never been seen directly: a
black hole.

Studies of the bright light emitted by the
swirling gas frequently indicate not only that a
black hole is present, but also likely attributes.

The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering
at a rate of 450 times a second.

Given a
previous
mass estimate for the central object of seven times the mass of our
Sun, the rate of the

fast flickering can be
explained by a black hole
that is rotating very rapidly.

What physical mechanisms actually cause the flickering — and a slower quasi-periodic
oscillation (QPO) — in
accretion disks surrounding
black holes and
neutron stars remains a topic of much research.

Young suns still lie
within dusty NGC 7129, some
3,000 light-years away toward the royal
constellation
Cepheus.

While these stars
are at a relatively tender age, only a few million years old, it is likely
that our own Sun formed in a similar stellar nursery some
five billion years ago.

Most noticeable in the
sharp, (zoomable) image are the
lovely bluish dust clouds
that reflect the youthful starlight,
but the smaller, deep
red crescent shapes are also markers of energetic,
young stellar objects.

Known as
Herbig-Haro
objects, their shape and color is
characteristic of glowing hydrogen gas
shocked by
jets streaming away from newborn stars.

Ultimately the natal gas and dust in the region
will be dispersed, the
stars
drifting apart as the loose
cluster orbits the center of the Galaxy.

At the estimated distance of
NGC 7129, this telescopic view spans
about 40 light-years.

Portuguese navigator
Ferdinand Magellan and his crew had plenty
of time to study the southern sky during the
first circumnavigation of planet Earth.

As a result, two celestial wonders
easily visible for southern hemisphere skygazers
are known as the Clouds of Magellan.

These cosmic clouds are now understood to be dwarf
irregular galaxies,
satellites
of our larger spiral Milky Way Galaxy.

The Small
Magellanic Cloud
actually spans 15,000 light-years or so
and contains several hundred million stars.

About 210,000 light-years away in the constellation
Tucana,
it is more distant than other known Milky Way
satellite galaxies, including the
Canis Major
and
Sagittarius
Dwarf galaxies and the
Large
Magellanic Cloud.

This
sharp image also includes two foreground globular
star clusters NGC 362 (bottom right) and 47 Tucanae.

Spectacular 47 Tucanae
is a mere 13,000 light-years away and seen here to the left of the
Small Magellanic Cloud.

Blown by the wind from a massive star, this interstellar
apparition has a surprisingly
familiar shape.

Cataloged as NGC 7635, it is also known simply
as The
Bubble Nebula.

Although it looks delicate, the 10 light-year diameter
bubble offers evidence of
violent processes at work.

Above and right of the Bubble’s center is a hot,
O-type star, several hundred thousand
times more luminous and approximately 45 times more massive
than the Sun.

A fierce stellar wind and intense radiation from that
star has blasted out the
structure of glowing gas
against denser material
in a surrounding
molecular
cloud.

The intriguing Bubble Nebula lies a mere
11,000 light-years away toward the boastful constellation
Cassiopeia.

A false-color
Hubble palette was used to create
this sharp image and
shows emission from sulfur, hydrogen, and oxygen atoms in red,
green, and blue hues.

The image data
was recorded using a small telescope under
clear, steady skies, from Mount Wilson Observatory.

What does Earth look like from the planet Mercury?

The robotic spacecraft
MESSENGER
found out as it looked toward the
Earth during its closest approach to the
Sun about three months ago.

The Earth and Moon
are visible as the double spot on the lower left of the
above image.

Now MESSENGER was not at Mercury when it took the above image, but at a
location
from which the view would be similar.

From Mercury, both the
Earth and its
comparatively large moon will always appear as small circles of reflected sunlight and will never show a
crescent phase.

MESSENGER has zipped right by
Mercury three
times since being
launched in 2004, and is scheduled to enter orbit around the innermost planet in March of 2011.

The sky toward the
center of our Galaxy is filled with a wide variety of
celestial wonders,
many of which are visible from a dark location with common
binoculars.

Constellations near the
Galactic Center include
Sagittarius,
Libra,
Scorpius,
Scutum, and
Ophiuchus.

Nebulas include
Messier objects
M8,
M16,
M20, as well as the
Pipe and
Cat’s Paw nebulas.

Visible
open star clusters include
M6,
M7,
M21,
M23,
M24, and
M25, while
globular star cluster
M22 is also visible.

A hole in the dust toward the
Galactic Center reveals a bright region filled with distant stars known as
Baade’s Window, which is visible between
M7 and
M8.

Moving your cursor over the
above image the will bring up an un-annotated version.

Could life once have survived on Mars?

Today, neither
animal nor
plant life from
Earth could survive for very long on
Mars because at least one key ingredient — liquid
water — is essentially absent on the red planet’s rusty surface.

Although evidence from the
martian rovers indicates that long ago
Mars might once have had
liquid water on its surface, that water might also have been
too acidic for familiar life forms to thrive.

Recently, however, a newly detailed analysis of an unusual outcropping of rock and soil chanced upon in 2005 by the robotic
Spirit rover has uncovered a clue indicating that not all of Mars was always so acidic.

The mound in question, dubbed
Comanche Outcrop and visible near the top of the
above image, appears to contain unusually
high concentrations of elements such as magnesium iron
carbonate.

The above image is shown in colors exaggerated to highlight the differences in composition.

Since these
carbonates
dissolve in acid, the persistence of these mounds indicates that water perhaps less
acidic and more
favorable for life might have once flowed across Mars.

More detailed analyses and searches for other signs will surely continue.

The stars are not alone.

In the disk of our
Milky Way Galaxy
about 10 percent of visible matter is in the form of gas, called the
interstellar medium (ISM).

The ISM is
not uniform,
and shows patchiness even near our
Sun.

It can be quite difficult to detect the
local ISM because it is so tenuous and emits so little light.

This mostly hydrogen gas, however, absorbs some very
specific colors that can be detected in the light of the
nearest stars.

A working map of the local
ISM within 10 light-years
based on recent observations is shown above.

These observations show that our
Sun is moving through a
Local Interstellar Cloud as this cloud flows outwards from the
Scorpius-Centaurus Association star forming region.

Our Sun may exit the Local Interstellar Cloud, also called the Local Fluff,
during the next 10,000 years.

Much remains unknown about the local
ISM, including details of its distribution,
its origin, and how it affects the
Sun and the
Earth.

This ominous, dark shape sprawling across the face of the Sun
is a coronal hole –
a low density region extending above
the surface where the solar magnetic field opens freely into
interplanetary space.

Studied extensively
from
space since the 1960s in
ultraviolet and
x-ray light, coronal holes are known to be the source of
the high-speed
solar wind, atoms and electrons
which flow outward along the open
magnetic field lines.

During periods of low activity,
coronal holes typically cover
regions just above the Sun’s poles.

But this extensive coronal hole
dominated the Sun’s northern hemisphere earlier this week, captured
here in extreme ultraviolet light by cameras onboard
the Solar Dynamics Observatory.

The solar wind streaming from this coronal hole
triggered auroral displays
on planet Earth.

Even though you may have just read an email
claiming Mars will be incredibly bright tonight,
the brightest star on the horizon is not Mars.

From central Iran on August 24th,
the brightest star in this
twilight
desert skyview
is Venus, aka the Evening Star.

But a bright Mars is in the picture, just above and right
of more brilliant Venus.

Despite claims in the internet’s
annually returning Mars Hoax
that Mars will be as big and bright as the Full Moon,
this celestial scenario is very similar to the western sky you can
see tonight.

Along with Mars, the still beautiful vista includes Spica,
alpha star of the
constellation
Virgo, above and left
of Venus.

Farther right of Venus,
Saturn peeks through the sunset’s
fading glow just above the clouds.

Near the opposite horizon, the Full Moon illuminating the
desert is about 400,000 times brighter
than Mars.

While hunting for comets in the skies above 18th century France,
astronomer Charles Messier
diligently kept a list of the things
he encountered that were definitely not comets.

This is number 27 on his
now
famous not-a-comet list.

In fact, 21st century astronomers would identify it as a
planetary
nebula, but it’s not a planet either, even though it may
appear round and
planet-like in a small telescope.

Messier 27 (M27) is an excellent example of a

gaseous emission nebula created
as a sun-like star runs out
of nuclear fuel in its core.

The nebula forms as the star’s outer layers are expelled into
space, with a visible glow generated by atoms excited by the dying
star’s intense but invisible
ultraviolet light.

Known by the popular name of the
Dumbbell
Nebula, the beautifully
symmetric interstellar gas cloud is over 2.5 light-years across and
about 1,200 light-years away in the
constellation
Vulpecula.

This impressive color
composite highlights details within
the well-studied central region and fainter, seldom imaged
features in the nebula’s outer halo.

It includes narrowband images recorded using
filters sensitive to emission from oxygen atoms, shown in
blue-green hues, and hydrogen atoms in red.

Do other rich planetary systems exist?

Our Solar System has the most planets of any known star, most probably because it is so hard to detect
planets around other stars.

Sensitive measurements, though, have
now uncovered a slight but complex wobble of the Sun-like star
HD 10180 indicating that it has at least five planets
and possibly more, making it the richest
extra-solar planetary system yet known.

HD 10180′s planets were discovered in years of data using the sensitive
HARPS spectrograph attached to the
ESO’s 3.6-meter telescope in
La Silla,
Chile.

The planetary system appears quite different than
our Solar System,
since all of HD 10180′s discovered planets have
Neptune-like masses but orbit inside the
distance of Mars.

An artist’s depiction of flying into this system is shown in the
above video.

In the future, more sensitive data taken over longer time periods may extend the
star-wobble detection technique
into the realm of uncovering more distant and
more Earth-like planets.

What’s the matter with this cluster of galaxies?

To find out what forms matter takes in the
Abell 1689 cluster requires not only deep images from telescopes like the
Hubble Space Telescope, but detailed
computer modeling as well.

To start, almost every fuzzy yellow patch in the
above image is an entire galaxy.

A close inspection, however, shows that many background galaxies are strangely magnified and distorted into
long curving arcs by the
gravitational lens deflections of the cluster.

Computer analyses of the
placement and smoothness of these arcs indicate that in addition to the matter in the galaxies you can see, the cluster must also contain a significant amount of
dark matter such as the model digitally superposed in
purple.

Now Abell 1689 remains enigmatic because the arcs are so numerous and diverse that no single
dark matter model has emerged that can
explain them all and still remain consistent with dark matter models needed to constrain their motion.

Still, the detailed information available from
clusters of galaxies like Abell 1689 gives hope that one day full solutions will be found that will not only fully reveal the
dark matter in clusters,
but also reveal the amounts of
dark energy
in the
universe
needed to lie along the line of sight to the
distant arcs.

Have you ever seen the Milky Way’s glow create shadows?

To do so, conditions need to be just right.

First and foremost, the sky must be relatively clear of clouds so that the
long band of the
Milky Way’s central disk can be seen.

The surroundings must be very near to completely dark, with no bright
artificial lights visible anywhere.

Next, the
Moon cannot be anywhere above the horizon,
or its glow will dominate the landscape.

Last, the shadows
can best be caught on long camera exposures.

In the above image taken in
Port Campbell National Park,
Victoria,
Australia,
seven 15-second images of the ground and
de-rotated sky were digitally added to bring up the needed light and detail.

In the foreground lies
Loch Ard Gorge, named after a
ship that tragically ran aground in
1878.

The two rocks pictured are the remnants of a collapsed arch and are named Tom and Eva after the only two people who survived that
Loch Ard ship wreck.

A close inspection of the
water just before the rocks will show shadows in light thrown by our
Milky Way galaxy.

Low clouds are visible moving through the serene scene in
this movie.

Is this one galaxy or two?

This question came to light in 1950 when astronomer
Art Hoag
chanced upon this unusual
extragalactic object.

On the outside is a
ring dominated by bright blue stars,
while near the center lies a ball of much redder stars
that are likely much older.

Between the two is a
gap that appears almost completely dark.

How Hoag’s Object
formed remains unknown, although similar objects
have now been
identified and collectively labeled
as a form of
ring galaxy.

Genesis hypotheses include a
galaxy collision
billions of years ago and the gravitational affect of a
central bar that has
since vanished.

The above
photo taken by the
Hubble Space Telescope
in July 2001 reveals unprecedented details of Hoag’s Object and may yield a
better understanding.

Hoag’s Object spans about 100,000
light years and lies about 600 million light years away toward the constellation of the Snake
(Serpens).

Coincidentally, visible in the gap
(at about one o’clock) is yet another
ring galaxy that likely lies
far in the distance.

Storms on the distant horizon and comet dust raining through the
heavens above are combined in this alluring
nightscape.

The scene was recorded
in the early hours of August 13 from
the Keota Star Party site on the
Pawnee National Grasslands
of northeastern Colorado, USA.

Looking east across the prairie,
the
composite of 8 consecutive
exposures each 30 seconds long captures the flash of
lightning and a bright Perseid
meteor.

On the right, even the clouds can’t block the light from brilliant
planet Jupiter, whose mythological
namesake
knew how to handle both lightning bolts and meteors.

Of course, this meteor’s streak points back toward the
shower’s radiant
in the heroic constellation Perseus,
sharing a starry background that includes the
Pleiades star
cluster poised above the storm clouds.

Just above the bright meteor lies the faint
Andromeda Galaxy.