Unusual Rocks near Pahrump Hills on Mars
Image Credit:
NASA,
JPL-Caltech,
MSSS
Explanation:
How did these Martian rocks form?
As the robotic
Curiosity rover
has approached
Pahrump Hills on
Mars,
it has seen an interesting and textured landscape dotted by some unusual rocks.
The
featured image shows a
curiously round rock spanning about two centimeters across.
Seemingly a larger version of
numerous spherules
dubbed
blueberries found by the
Opportunity rover on Mars in 2004,
what caused this roundness remains unknown.
Possibilities include
frequent tumbling in flowing water,
sprayed molten rock
in a volcanic eruption, or a
concretion mechanism.
The
inset image, taken a few days later, shows another small but unusually shaped rock structure.
As Curiosity rolls around and up
Mount Sharp,
different layers of the landscape will be imaged and studied to better
understand the ancient history of the region and to investigate whether
Mars could once have
harbored life.
A Full Circle Rainbow over Australia
Image Credit & Copyright:
Colin Leonhardt
(Birdseye View Photography)
Explanation:
Have you ever seen an entire rainbow?
From the ground, typically, only the top portion of a rainbow is
visible because directions toward the ground have fewer raindrops.
From the air, though, the entire 360 degree circle of a
rainbow is more commonly visible.
Pictured here,
a full circle rainbow was captured over
Cottesloe Beach near
Perth,
Australia
last year by a helicopter flying between a setting sun and a downpour.
An observer-dependent
phenomenon
primarily caused by the
internal reflection
of sunlight by raindrops, the 84-degree diameter
rainbow
followed the helicopter, intact, for about 5 kilometers.
As a
bonus,
a
second rainbow
that was more faint and color-reversed was visible outside the first.
The Butterfly Nebula from Hubble
Image Credit:
NASA,
ESA, and the
Hubble SM4 ERO Team;
Reprocessing & Copyright:
Francesco Antonucci
Explanation:
The bright clusters and nebulae of planet Earth's night sky are often
named for
flowers or
insects.
Though its wingspan covers over 3 light-years,
NGC 6302 is no
exception.
With an estimated surface temperature of about 250,000 degrees C,
the dying central star of this particular
planetary nebula has become exceptionally
hot, shining brightly in ultraviolet light but hidden from
direct view by a dense torus of dust.
This
sharp close-up
of the dying star's nebula was recorded
in 2009 by the Hubble Space Telescope's Wide Field Camera 3,
and is presented here in reprocessed colors.
Cutting across a bright cavity of ionized gas, the dust
torus
surrounding the central star is near
the center of this view, almost edge-on to the line-of-sight.
Molecular hydrogen
has been
detected in the hot star's dusty cosmic shroud.
NGC 6302 lies about 4,000 light-years away in the
arachnologically
correct constellation of the Scorpion
(
Scorpius).
The Bubble Nebula
Image Credit &
Copyright:
Bernard Michaud
Explanation:
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.
Below and left of the Bubble's center is a hot,
O star, several hundred thousand
times more luminous and around 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 and associated cloud complex
lie a mere 11,000 light-years away toward the boastful constellation
Cassiopeia.
This tantalizing view
of the cosmic bubble is composed from narrowband image data,
recording emission from the region's ionized hydrogen and oxygen atoms.
To create the
three
color image, hydrogen and oxygen emission
were used for red and blue and combined to create the
green channel.
Mars, Antares, Moon and Saturn
Image Credit &
Copyright:
Tamas Ladanyi
(TWAN)
Explanation:
Mars, Antares,
Moon, and
Saturn
are the brightest celestial beacons in
this serene sky.
The Sun's golden light is still scattered along the
southwestern horizon though, captured after
sunset on September 28.
The evening gathering of wandering planets and Moon along
with the
bright star viewed as
an equal to Mars and
the Scorpion's Heart was enjoyed around planet Earth.
But from the photographer's perspective looking across
the calm waters of Lake Balaton, Hungary, they
were joined by a more terrestrial sailboat mast light.
Mast light, bright star, planets and Moon are all posing
near the
plane of the ecliptic.
From the Temple of the Sun to the Temple of the Moon
Image Credit & Copyright:
Dave Lane
Explanation:
What connects the Sun to the Moon?
Many answers have been given throughout
history, but in the case of today's featured image, it appears to be the plane of our
Milky Way Galaxy.
The 16-image panorama was taken in
Capitol Reef National Park,
Utah, USA where two
sandstone monoliths -- the Temple of the Moon on the right and the
Temple of the Sun
on the left -- rise dramatically from the desert.
Each
natural monument
stands about 100 meters tall and survives from the
Jurassic period 160 million years ago.
Even older are many of the stars and nebulas that dot the celestial background, including the
Andromeda Galaxy.
Tomorrow the Earth will connect the Sun to the Moon by way of its shadow: a
total lunar eclipse will be visible from many locations
around the globe.
NGC 6823: Cloud Sculpting Star Cluster
Image Credit & Copyright:
Donald P. Waid
(Waid Observatory)
Explanation:
Star cluster NGC 6823 is slowly turning gas clouds into stars.
The center of the open cluster, visible on the upper right,
formed only about two million years ago and is
dominated in brightness by a host of
bright young blue stars.
Some outer parts of the cluster, visible in the
featured image's center
as the stars and pillars of
emission nebula
NGC 6820, contain even younger stars.
The
huge pillars of gas and
dust likely get their elongated shape by
erosion from hot radiation emitted from the
brightest cluster stars.
Striking
dark globules
of gas and dust are also visible across the upper left of the
featured image.
Open star cluster
NGC 6823 spans
about 50 light years and lies about 6000
light years away toward the
constellation
of the Fox (
Vulpecula).
Source -
www.nasa.gov
