M51: The Whirlpool Galaxy
Image Credit &
Copyright:
Martin Pugh
Explanation:
Follow the handle of
the Big Dipper away from the dipper's bowl until
you get to the handle's last bright star.
Then, just slide your telescope a little
south and west and
you might find this
stunning pair of interacting galaxies,
the 51st entry
in Charles Messier famous catalog.
Perhaps the
original
spiral nebula, the large galaxy with
well defined spiral structure is also cataloged as NGC 5194.
Its
spiral arms and dust lanes
clearly sweep in front of its companion galaxy (right),
NGC 5195.
The pair are
about 31 million light-years distant and
officially lie within the angular boundaries of the small constellation
Canes
Venatici.
Though M51 looks faint and fuzzy to the
eye, deep images
like
this one can reveal striking colors and the faint
tidal
debris around the smaller galaxy
Cluster and Starforming Region Westerlund 2
Image Credit &
Copyright:
NASA,
ESA, the
Hubble Heritage Team
(STScI /
AURA),
A. Nota (ESA/STScI), and the Westerlund 2 Science Team
Explanation:
Located 20,000 light-years away in the constellation Carina,
the young cluster and starforming region
Westerlund 2 fills this cosmic scene.
Captured with Hubble's cameras in near-infrared and visible light,
the stunning image is a
celebration of the 25th anniversary
of the launch of the Hubble Space Telescope on April 24, 1990.
The cluster's dense concentration of luminous, massive stars is about
10 light-years across.
Strong winds and radiation from those massive young stars have sculpted
and shaped the region's gas and dust,
into starforming pillars that point back to the central cluster.
Red dots surrounding the bright stars are the cluster's
faint newborn stars, still within their natal gas and dust cocoons.
But brighter blue stars scattered around are likely not in the
Westerlund 2 cluster
and instead lie in the foreground of the
Hubble anniversary field of view.
Blue Tears and the Milky Way
Image Credit &
Copyright:
Rogelio Bernal
Andreo (Deep Sky Colors)
Explanation:
Lapping at rocks
along the shore of the Island of Nangan, Taiwan,
planet Earth,
waves are infused with a subtle blue light in this
sea and night skyscape.
Composed of a series of long exposures made on April 16
the image captures the faint glow from
Noctiluca scintillans.
Also known as sea sparkles or blue tears,
the marine plankton's bioluminescence is stimulated by wave motion.
City lights along the coast of mainland China shine
beneath low clouds in the west but stars and the
faint Milky Way
still fill the night above.
Over the horizon the galaxy's central bulge and dark rifts
seem to echo the rocks
and luminous waves.
Planetary Nebula Mz3: The Ant Nebula
Image Credit:
R. Sahai
(JPL) et al.,
Hubble Heritage Team,
ESA,
NASA
Explanation:
Why isn't this ant a big sphere?
Planetary nebula Mz3 is being cast off by a star similar to our
Sun
that is, surely, round.
Why then would the gas that is
streaming away create an
ant-shaped nebula that is distinctly not round?
Clues might include
the high 1000-kilometer per second speed of the expelled gas, the
light-year long length of the structure, and the
magnetism of the star
visible
above at the nebula's center.
One possible answer is that
Mz3 is hiding a second, dimmer star that
orbits close in to the bright star.
A competing
hypothesis holds that the central star's own spin and
magnetic field are channeling the gas.
Since the central star appears to be so similar to our own Sun,
astronomers hope that increased understanding of the history of
this giant space
ant
can provide useful insight into the likely future of our own
Sun and
Earth.
Space Station over Lunar Terminator
Image Credit & Copyright:
Dani Caxete
Explanation:
What's that in front of the Moon?
It's the
International Space Station.
Using precise timing, the
Earth-orbiting space platform
was photographed in front of a partially lit Moon last year.
The featured image was taken from
Madrid,
Spain
with an exposure time of only 1/1000 of a second.
In contrast, the duration of the transit of the
ISS across the entire Moon was about
half a second.
The sun-glinting
station can be seen
just to the dark side of the day / night line known as the
terminator.
Numerous circular
craters
are visible on the distant Moon, as well as comparatively rough,
light colored terrain known as
highlands, and relatively smooth, dark colored areas known as
maria.
On-line
tools can tell you when the International Space Station will be visible from your area.
Massive Nearby Spiral Galaxy NGC 2841
Image Credit:
Hubble,
Subaru;
Composition & Copyright:
Roberto Colombari
Explanation:
It is one of the more massive galaxies known.
A mere 46 million light-years distant, spiral galaxy NGC 2841
can be found in the northern constellation of
Ursa Major.
This sharp view of the gorgeous
island universe
shows off a striking yellow nucleus and galactic disk.
Dust lanes, small, pink star-forming regions, and young blue star clusters
are embedded in the patchy, tightly
wound
spiral arms.
In contrast, many other spirals
exhibit grand, sweeping arms with large star-forming regions.
NGC 2841
has a diameter of over 150,000 light-years,
even larger than
our own
Milky Way and captured by
this composite image
merging exposures from the orbiting 2.4-meter
Hubble Space Telescope and the ground-based 8.2-meter
Subaru Telescope.
X-ray images
suggest that resulting winds and stellar explosions create
plumes of hot gas extending into a halo around
NGC 2841.
Comet Churyumov Gerasimenko in Crescent
Image Credit:
ESA,
Rosetta,
NAVCAM; processing by
Giuseppe Conzo
Explanation:
What's happening to Comet 67P/Churyumov–Gerasimenko?
As the
3-km wide comet moves closer to the Sun, heat causes the nucleus to
expel gas and dust.
The
Rosetta spacecraft
arrived at the
comet's craggily double nucleus
last July and now is co-orbiting the Sun with the
giant dark iceberg.
Recent
analysis of data beamed back to Earth from the
robotic Rosetta spacecraft has shown that water being expelled by 67P has a significant difference with water on Earth, indicating that
Earth's water could not have originated from ancient collisions with comets like 67P.
Additionally, neither Rosetta nor its
Philae lander detected a magnetic field around the comet nucleus, indicating that
magnetism might have been unimportant in the evolution of the early Solar System.
Comet 67P, shown in a
crescent phase in false color,
should increase its evaporation rate as it nears its closest approach to the Sun in 2015 August,
when it reaches a Sun distance just a bit further out than the Earth.
Across the Sun
Image Credit &
Copyright:
Göran Strand
Explanation:
A long solar filament stretches across the relatively calm
surface of the Sun in this telescopic snap shot from April 27.
The
negative or inverted
narrowband image was made in the light of
ionized hydrogen atoms.
Seen at the upper left, the magnificent curtain of magnetized plasma
towers above surface and actually reaches beyond the Sun's edge.
How long is the solar filament?
About as long as the distance from Earth to Moon, illustrated
by the scale insert at the left.
Tracking toward the right across
the solar disk a day later
the long filament erupted, lifting away from the Sun's surface.
Monitored by
Sun
staring satellites, a coronal mass ejection was
also blasted from the site but is expected to swing wide of
our fair planet.
MESSENGER's Last Day on Mercury
Image Credit:
NASA,
Johns Hopkins Univ. APL,
Arizona State Univ., CIW
Explanation:
The first
to orbit Mercury, the MESSENGER spacecraft
came to rest
on this region of
Mercury's surface yesterday.
Constructed from MESSENGER image and laser altimeter data,
the scene looks north over the northeastern rim of the
broad, lava filled
Shakespeare basin.
The large, 48 kilometer (30 mile) wide crater Janacek
is near the upper left edge.
Terrain height is color coded with red regions
about 3 kilometers above blue ones.
MESSENGER'S final orbit was predicted to end
near the center, with the spacecraft impacting the surface
at nearly 4 kilometers per second (over 8,700 miles per hour)
and creating a new crater about 16 meters (52 feet) in diameter.
The
impact on the far side of Mercury was
not observed by telescopes, but
confirmed when no signal was detected from the spacecraft
given time to emerge from behind the planet.
Launched in 2004, the
MErcury
Surface,
Space
ENvironment,
GEochemisty and
Ranging spacecraft completed over 4,000 orbits after reaching the
Solar System's innermost planet in 2011.
Source -
NASA