Explanation:
Is this galaxy jumping through a giant ring of stars?
Probably not.
Although the precise
dynamics behind
the featured image is yet unclear, what is clear is that the pictured galaxy,
NGC 7714,
has been stretched and distorted by a recent collision with a neighboring galaxy.
This smaller neighbor,
NGC 7715,
situated off to the left of the featured frame, is thought to have charged right through
NGC 7714.
Observations indicate that the golden
ring pictured is composed of millions of older Sun-like stars
that are likely co-moving with the interior bluer stars.
In contrast, the bright center of
NGC 7714
appears to be undergoing a burst of new star formation.
NGC 7714 is located about 100 million
light years
away toward the constellation of the Fish
(Pisces).
The interactions between these galaxies
likely started about 150 million
years ago
and should continue for several hundred million
years more, after which a
single central galaxy may result.
The Milky Way over the Temple of Poseidon Image Credit & Copyright: Alexandros Maragos;
Rollover Annotation: Judy Schmidt
Explanation:
What's that glowing in the distance?
Although it may look like a
lighthouse, the rays of light near the horizon actually emanate from the
Temple of Poseidon at
Cape Sounion,
Greece.
Some temple
lights are even reflected in the
Aegean Sea in the foreground.
Although meant to be a monument to the sea, in this image,
the temple's lights seem to be pointing out locations on the sky.
For example, the wide ray toward the right fortuitously points toward the
Lagoon Nebula in the central band of our
Milky Way, which runs diagonally down the image from the upper left.
Also, the nearly vertical beam seems to point toward the star clouds near the direction of the
Wild Duck open cluster of stars.
The featured image was taken less than three weeks ago.
Explanation:
Telescopic observers on Earth have been treated to spectacular
views of Saturn lately as the ringed planet reached its 2015
opposition on May 23 at 0200 UT.
Of course opposition means opposite the Sun in Earth's sky.
So near
opposition Saturn is
up all night, at its closest and brightest
for the year.
These sharp images
taken within hours of the Sun-Earth-Saturn
alignment also show the strong brightening of Saturn's rings
known as the opposition surge or the
Seeliger Effect.
Directly illuminated, the ring's icy particles cast no shadows and
strongly backscatter sunlight toward planet Earth,
creating the dramatic surge in brightness.
Saturn currently stands in the
sky not far from bright Antares,
alpha star of the constellation Scorpius.
Explanation:
Many bright nebulae and star clusters in planet Earth's sky
are associated with the name of
astronomer
Charles Messier, from his famous 18th century catalog.
His
name is also given to these two large and remarkable craters
on the Moon.
Standouts in the dark, smooth lunar Sea of Fertility or Mare
Fecunditatis,
Messier (left) and Messier A have dimensions of 15 by 8
and 16 by 11 kilometers respectively.
Their elongated shapes are explained by
an extremely shallow-angle trajectory followed by
the impactor, moving left to right,
that gouged out the craters.
The shallow impact also resulted in two
bright rays of material
extending along the surface to the right, beyond the picture.
Intended to be viewed with
red/blue glasses (red for the left eye),
this striking stereo picture of the crater pair was recently created
from high resolution scans of two images
(AS11-42-6304,
AS11-42-6305)
taken during the Apollo 11 mission to the moon.
Explanation:
Why does this moon look like a sponge?
To better investigate,
NASA and
ESA sent the Saturn-orbiting robotic
spacecraft Cassini zooming past
Saturn's moon
Hyperion, once again, earlier this week.
One of the images beamed back to Earth is
featured above, raw and unprocessed.
Visible, as expected, are many
unusually shaped craters with an unusual dark material at the bottom.
Although Hyperion
spans about 250 kilometers, its small gravitational tug on
Cassini indicates that it is mostly empty space and so has very low
surface gravity.
Therefore, the
odd shapes of many of Hyperion's craters are thought to result from impacts that
primarily compress and eject surface material -- instead of the more
typical round craters that appear after a circular shock wave that explosively redistributes surface material.
Cassini is
on track for another flyby of
Saturn's
Dione in about two weeks.
Explanation:
Follow a sunset on a clear day against a distant horizon
and you might
glimpse
a green flash just as the Sun disappears, the sunlight
briefly refracted
over a long sight-line through atmospheric layers.
You can spot a green flash at sunrise too.
Pinpointing the exact place and time to see the rising Sun
peeking above the horizon is a little more difficult though, and
it can be harder still to catch a green flash from
the fainter rising Moon.
But well-planned snapshots did record a green flash at the
Full
Moon's upper edge on June 2nd,
from the Roque de los Muchachos Observatory
on the Canary Island of La Palma.
Looking a little south of due east,
this long telephoto view finds the rising Moon above mountains and
a sea of clouds.
In sunlit profile are the mountaintop
Teide Observatory telescope domes
on the island of Tenerife some
143 kilometers away.
Explanation:
What would it look like to fly over dwarf planet Ceres?
Animators from the
German Aerospace Center
recently took actual images and height data from NASA's robotic Dawn
mission -- currently visiting Ceres -- to generate several
fascinating virtual sequences.
The
featured video begins with a mock orbit around the 950-km wide space rock, with the crater featuring two of the
enigmatic white spots soon rotating into view.
The next sequences take the viewer around the
Ceres'
north and south poles, and then over a
limb of the dark world highlighting its heavily cratered surface.
Here,
terrain height on the
asteroid belt's largest object has been digitally doubled,
while an artificial star field has been added in the background.
The Dawnspacecraft
will likely remain an unusual
artificial moon of
Ceres long after its mission concludes.
Explanation:
It's the dim star, not the bright one, near the center of
NGC 3132 that created this odd but beautiful
planetary nebula.
Nicknamed the
Eight-Burst Nebula and the Southern
Ring Nebula, the glowing gas originated in the
outer layers of a star like our
Sun.
In this
representative
color picture, the hot blue pool of light seen surrounding this
binary system
is energized by the hot surface of the faint star.
Although
photographed to explore unusual symmetries, it's the asymmetries that
help make this
planetary nebula so intriguing.
Neither the unusual shape of the surrounding cooler
shell nor the structure and
placements of the cool filamentary
dust lanes running across
NGC 3132
are well understood.
