Earth Weather / Space Weather

Meteorites from Asteroid Vesta

By: Susie77, 1:15 AM GMT on December 31, 2011



Space Mountain Produces Terrestrial Meteorites

Dec. 30, 2011: When NASA's Dawn spacecraft
entered orbit around giant asteroid Vesta in July, scientists fully
expected the probe to reveal some surprising sights. But no one expected
a 13-mile high mountain, two and a half times higher than Mount
Everest, to be one of them.


The existence of this towering peak could solve a longstanding
mystery: How did so many pieces of Vesta end up right here on our own
planet?
Space Mountain (side view, 558px)
A side view of Vesta's great south polar mountain. [more]

For many years, researchers have been collecting Vesta meteorites
from "fall sites" around the world. The rocks' chemical fingerprints
leave little doubt that they came from the giant asteroid. Earth has
been peppered by so many fragments of Vesta, that people have actually
witnessed fireballs caused by the meteoroids tearing through our
atmosphere. Recent examples include falls near the African village of
Bilanga Yanga in October 1999 and outside Millbillillie, Australia, in
October 1960.


"Those meteorites just might be pieces of the basin excavated when
Vesta's giant mountain formed," says Dawn PI Chris Russell of UCLA.
Curiosity and the Solar Storm (signup)
Russell believes the mountain was created by a 'big bad impact'
with a smaller body; material displaced in the smashup rebounded and
expanded upward to form a towering peak. The same tremendous collision
that created the mountain might have hurled splinters of Vesta toward
Earth.


"Some of the meteorites in our museums and labs," he says, "could
be fragments of Vesta formed in the impact -- pieces of the same stuff
the mountain itself is made of."


To confirm the theory, Dawn's science team will try to prove that
Vesta's meteorites came from the mountain's vicinity. It's a "match
game" involving both age and chemistry.


"Vesta formed at the dawn of the solar system," says Russell.
"Billions of years of collisions with other space rocks have given it a
densely cratered surface."


The surface around the mountain, however, is tellingly smooth.
Russell believes the impact wiped out the entire history of cratering in
the vicinity. By counting craters that have accumulated since then,
researchers can estimate the age of the landscape.
Space Mountain (cross sections, 558px)
Cross-section of the south polar mountain on Vesta with the
cross sections of Olympus Mons on Mars, the largest mountain in the
solar system, and the Big lsland of Hawaii as measured from the floor of
the Pacific, the largest mountain on Earth. These latter two mountains
are both shield volcanoes.Credit: Russell et. al. (2011), EPSC

"In this way we can figure out the approximate age of the
mountain's surface. Using radioactive dating, we can also tell when the
meteorites were 'liberated' from Vesta. A match between those dates
would be compelling evidence of a meteorite-mountain connection."


For more proof, the scientists will compare the meteorites' chemical makeup to that of the mountain area.


"Vesta is intrinsically but subtly colorful. Dawn's sensors can
detect slight color variations in Vesta's minerals, so we can map
regions of chemicals and minerals that have emerged on the surface. Then
we'll compare these colors to those of the meteorites."


Could an impact on Vesta really fill so many museum display cases on Earth? Stay tuned for answers..


Author: Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA

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Beautiful Comet Lovejoy Puts on a Show

By: Susie77, 3:52 AM GMT on December 23, 2011


Images of Comet Lovejoy, now visible from Southern Hemisphere











Image credit: Colin Legg.

Image credit: Colin Legg.









Comet Lovejoy is putting on an amazing show in the predawn skies of the Southern Hemisphere. Here are some beautiful images!













Comet Lovejoy surprised a lot of people when it survived a very
close encounter with the sun on December 16, 2011. It skimmed through
the solar corona where temperatures reach up to two million degrees
Fahrenheit, about 140,000 kilometers (87,000 miles) above the sun’s
surface. Comet Lovejoy
is now racing away from the sun, and it’s putting on a grand predawn
show in the sky visible from the Southern Hemisphere. Unfortunately, the
comet is not visible from the Northern Hemisphere, so us northerners
have to live vicariously through the astrophotographers who have been
bringing us stunning images of Comet Lovejoy.
Grahame Kelaher,
an Australian astrophotographer, sent this jaw-dropping image of Comet
Lovejoy to EarthSky. He took it near Perth on December 22, 2011 using a
Canon 7D camera. You can clearly see streaming structures in the comet’s
dust tail – that’s the bright veil-like tail making a slight
graceful curve to the left in the photo. The dust tail is made of dust
particles tracing the comet’s path, lit by reflected sunlight. The
fainter straight tail is the ion or gas tail, pointing directly
away from the sun as a result of its interaction with solar wind and
the sun’s magnetic field. But where is the comet’s nucleus or core? It’s not visible, perhaps it’s shrouded in the volatiles
(easily evaporated substances) surrounding it. There’s a lot of
curiosity about the condition of Comet Lovejoy’s nucleus. Will it remain
intact? Or will it disintegrate due to the stress of its close
encounter with the sun on December 16?

Fine
streamers are clearly visible in this image of Comet Lovejoy, taken on
December 22, 2011 near Perth, Australia. Image credit: Grahame Kelaher.
Grahame also obtained this wide-angle view of the comet over the
suburbs of Perth, Australia on December 21, 2011. Anyone who has
stargazed in the suburbs knows how light pollution obscures the very
faintest stars. That Grahame could obtain this image over Perth
indicates that this comet is pretty darned bright!
Comet Lovejoy graces the sky over the suburbs of Perth Australia on December 21, 2011. Image credit: Grahame Kelaher.
Another Australian photographer, Colin Legg, photographed a lovely
view of Comet Lovejoy on December 21, 2011, over the Mandurah Estuary
near Perth, catching its ghostly reflection on the water. Fine streamers
in the dust tail are also evident in this photo. For the photography
enthusiasts curious about technical details, Colin obtained this image
with a Canon 5D2 using a 73 mm focal length lens, a f/4 aperture
opening, an ISO setting of 3200, and an exposure time of 12 seconds.
Comet Lovejoy reflected in the water of Mandurah Esturary near Perth, on December 21, 2011. Image Credit: Colin Legg.
He also created a series of time-lapse wide-angle photos on December
21, 2011 with a 24 mm focal length lens, using several different
exposure times, ISO, and aperture settings. Click the link below to see
it.
Comet Lovejoy (2011 W3) rising over Western Australia from Colin Legg on Vimeo.
Currently, the constellation Sagittarius is the backdrop for Comet
Lovejoy. That will gradually change as the comet moves away from the
sun.
What will Comet Lovejoy do next? Remain stable? Break apart? Stay
relatively bright, or rapidly fade away? Stay tuned for future updates!

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Almost As Hot As Texas in July :)

By: Susie77, 7:46 PM GMT on December 20, 2011

NASA DISCOVERS FIRST EARTH-SIZE PLANETS BEYOND OUR SOLAR SYSTEM



MOFFET FIELD, Calif. -- NASA's Kepler mission has discovered the first

Earth-size planets orbiting a sun-like star outside our solar system.

The planets, called Kepler-20e and Kepler-20f, are too close to their

star to be in the so-called habitable zone where liquid water could

exist on a planet's surface, but they are the smallest exoplanets

ever confirmed around a star like our sun.



The discovery marks the next important milestone in the ultimate

search for planets like Earth. The new planets are thought to be

rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87

times the radius of Earth. Kepler-20f is slightly larger than Earth,

measuring 1.03 times its radius. Both planets reside in a five-planet

system called Kepler-20, approximately 1,000 light-years away in the

constellation Lyra.



Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every

19.6 days. These short orbital periods mean very hot, inhospitable

worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an

average day on the planet Mercury. The surface temperature of

Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass.



"The primary goal of the Kepler mission is to find Earth-sized planets

in the habitable zone," said Francois Fressin of the

Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead

author of a new study published in the journal Nature. "This

discovery demonstrates for the first time that Earth-size planets

exist around other stars, and that we are able to detect them."



The Kepler-20 system includes three other planets that are larger than

Earth but smaller than Neptune. Kepler-20b, the closest planet,

Kepler-20c, the third planet, and Kepler-20d, the fifth planet, orbit

their star every 3.7, 10.9 and 77.6 days. All five planets have

orbits lying roughly within Mercury's orbit in our solar system. The

host star belongs to the same G-type class as our sun, although it is

slightly smaller and cooler.



The system has an unexpected arrangement. In our solar system, small,

rocky worlds orbit close to the sun and large, gaseous worlds orbit

farther out. In comparison, the planets of Kepler-20 are organized in

alternating size: large, small, large, small and large.



"The Kepler data are showing us some planetary systems have

arrangements of planets very different from that seen in our solar

system," said Jack Lissauer, planetary scientist and Kepler science

team member at NASA's Ames Research Center in Moffett Field, Calif.

"The analysis of Kepler data continue to reveal new insights about

the diversity of planets and planetary systems within our galaxy."



Scientists are not certain how the system evolved but they do not

think the planets formed in their existing locations. They theorize

the planets formed farther from their star and then migrated inward,

likely through interactions with the disk of material from which they

originated. This allowed the worlds to maintain their regular spacing

despite alternating sizes.



The Kepler space telescope detects planets and planet candidates by

measuring dips in the brightness of more than 150,000 stars to search

for planets crossing in front, or transiting, their stars. The Kepler

science team requires at least three transits to verify a signal as a

planet.



The Kepler science team uses ground-based telescopes and the Spitzer

Space Telescope to review observations on planet candidates the

spacecraft finds. The star field Kepler observes in the

constellations Cygnus and Lyra can be seen only from ground-based

observatories in spring through early fall. The data from these other

observations help determine which candidates can be validated as

planets.



To validate Kepler-20e and Kepler-20f, astronomers used a computer

program called Blender, which runs simulations to help rule out other

astrophysical phenomena masquerading as a planet.



On Dec. 5 the team announced the discovery of Kepler-22b in the

habitable zone of its parent star. It is likely to be too large to

have a rocky surface. While Kepler-20e and Kepler-20f are Earth-size,

they are too close to their parent star to have liquid water on the

surface.



"In the cosmic game of hide and seek, finding planets with just the

right size and just the right temperature seems only a matter of

time," said Natalie Batalha, Kepler deputy science team lead and

professor of astronomy and physics at San Jose State University. "We

are on the edge of our seats knowing that Kepler's most anticipated

discoveries are still to come."



For more information about the Kepler mission and to view the digital

press kit, visit:



http://www.nasa.gov/kepler

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Journey to the Center of the Sun

By: Susie77, 10:54 PM GMT on December 16, 2011

(Well, sort of)

~~~~~~~~~~~~~~~~~~~~~~~~~~



Comet Lovejoy Plunges into the Sun and Survives

Dec. 16, 2011: This morning, an armada of
spacecraft witnessed something that many experts thought impossible. 
Comet Lovejoy flew through the hot atmosphere of the sun and emerged
intact.

"It's absolutely astounding," says Karl Battams of the Naval
Research Lab in Washington DC.  "I did not think the comet's icy core
was big enough to survive plunging through the several million degree
solar corona for close to an hour, but Comet Lovejoy is still with us."

The comet's close encounter was recorded by at least five
spacecraft: NASA's Solar Dynamics Observatory and twin STEREO probes,
Europe's Proba2 microsatellite, and the ESA/NASA Solar and Heliospheric
Observatory.  The most dramatic footage so far comes from SDO, which saw
the comet go in (movie) and then come back out again (movie).
Comet Lovejoy (exit splash, 512px)
NASA's Solar Dynamics Observatory caught Comet Lovejoy emerging from its scorching close encounter with the sun. [Entrance movie:Quicktime (22 MB), m4v (0.8 MB)] [Exit movie:Quicktime (26 MB), m4v (0.8 MB)]

In the SDO movies, the comet's tail wriggles wildly as the comet
plunges through the sun's hot atmosphere only 120,000 km above the
stellar surface. This could be a sign that the comet was buffeted by
plasma waves coursing through the corona.  Or perhaps the tail was
bouncing back and forth off great magnetic loops known to permeate the
sun's atmosphere.  No one knows.

"This is all new," says Battams.  "SDO is giving us our first look1 at comets travelling through the sun's atmosphere. How the two interact is cutting-edge research." 
Curiosity and the Solar Storm (signup)
“The motions of the comet material in the sun’s magnetic  field
are just fascinating,” adds SDO project scientist Dean Pesnell of the
Goddard Space Flight Center.   “The abrupt changes in direction reminded
me of how the solar wind affected the tail of Comet Encke in 2007 (movie).”

Comet Lovejoy was discovered on Dec. 2, 2011, by amateur
astronomer Terry Lovejoy of Australia.  Researchers quickly realized
that the new find was a member of the Kreutz family of sungrazing
comets.  Named after the German astronomer Heinrich Kreutz, who first
studied them, Kreutz sungrazers are fragments of a single giant comet
that broke apart back in the 12th century (probably the Great Comet of
1106).  Kreutz sungrazers are typically small (~10 meters wide) and
numerous. The Solar and Heliospheric Observatory sees one falling into
the sun every few days.

At the time of discovery, Comet Lovejoy appeared to be at least
ten times larger than the usual Kreutz sungrazer, somewhere in the in
the 100 to 200 meter range.  In light of today's events, researchers are
re-thinking those numbers.
Comet Lovejoy (coronagraph splash, 512px)
This coronagraph image from the Solar and Heliospheric
Observatory shows Comet Lovejoy receding from the sun after its close
encounter. The horizontal lines through the comet's nucleus are digital
artifacts caused by saturation of the detector; Lovejoy that that
bright! [movie]

"I'd guess the comet's core must have been at least 500 meters in
diameter; otherwise it couldn't have survived so much solar heating,"
says Matthew Knight. "A significant fraction of that mass would have
been lost during the encounter. What's left is  probably much smaller
than the original comet."

SOHO and NASA's twin STEREO probes are monitoring the comet as it
recedes from the sun. It is still very bright and should remain in range
of the spacecrafts' cameras for several days to come. Researchers will
be watching closely, because there a good chance for more surprises.

"There is still a possibility that Comet Lovejoy will start to
fragment," continues Battams. "It’s been through a tremendously
traumatic event; structurally, it could be extremely weak. On the other
hand, it could hold itself together and disappear back into the recesses
of the solar system."

"It's hard to say," agrees Knight.  "There has been so little work
on what happens to sungrazing comets after perihelion (closest
approach).  This continues to be fascinating.”


Author:Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit: Science@NASA

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Curiosity and the Solar Storm

By: Susie77, 10:59 PM GMT on December 14, 2011



Curiosity and the Solar Storm

Dec. 14, 2011: On Nov. 26th,
Curiosity blasted off from Cape Canaveral atop an Atlas 5 rocket. 
Riding a plume of fire through the blue Florida sky, the car-sized rover
began a nine month journey to search for signs of life Mars.

Meanwhile, 93 million miles away, a second lesser-noticed Mars
launch was underway.  Around the time that Curiosity’s rocket was
breaking the bonds of Earth, a filament of magnetism erupted from the
sun, hurling a billion-ton cloud of plasma (a “CME”) toward the Red
Planet.
Curiosity and the Solar Storm (two launches, 558px)
The two Mars launches of Nov. 26, 2011. On the left, a solar
explosion hurls a CME toward the Red Planet (Credit: SOHO). On the
right, the Mars Science Lab or "Curiosity" lifts off from Cape
Canaveral. (Credit: Howard Eskildsen of Titusville, FL)

There was no danger of a collision—Mars rover vs. solar storm. 
Racing forward at 2 million mph, the plasma cloud outpaced Curiosity’s
rocket by a wide margin. 

Next time could be different, however.  With solar activity on the
upswing (Solar Max is expected in 2012-2013) it’s only a matter of time
before a CME engulfs the Mars-bound rover.

That suits some researchers just fine.  As Don Hassler of the
Southwest Research Institute (SWRI) in Boulder, Colorado, explains, “We
look forward to such encounters because Curiosity is equipped to study
solar storms."
Curiosity and the Solar Storm (signup)
Hassler is the principal investigator for Curiosity's Radiation
Assessment Detector--"RAD" for short.  The instrument, developed at SWRI
and Christian Albrechts University in Kiel, Germany, counts cosmic
rays, neutrons, protons and other particles over a wide range of
energies.  Tucked into the left front corner of the rover, RAD is about
the size of a coffee can and weighs only three pounds, but has
capabilities of Earth-bound instruments nearly 10 times its size.

Encounters with CMEs pose little danger to Curiosity.  By the time
a CME reaches the Earth-Mars expanse, it is spread so thin that it
cannot truly buffet the spacecraft. Nevertheless, RAD can sense what
happens as the CME passes by.

"RAD will be able to detect energetic particles accelerated by shock waves in some CMEs1,"
says Arik Posner of NASA’s Heliophysics Division in Washington DC.
"This could give us new insights into the inner physics of these giant
clouds."

There’s more to this, however, than pure heliophysics.  Future
human astronauts will directly benefit from RAD’s measurements during
the cruise phase.
Curiosity and the Solar Storm (rad, 200px)
A photo of the Radiation Assessment Detector (RAD) in the laboratory. [more]

"Curiosity is nestled inside its spacecraft, just like a real
astronaut would be," notes Frank Cucinotta, Chief Scientist for NASA’s
Space Radiation Program at the Johnson Space Center.  "RAD will give us
an idea of the kind of radiation a human can expect to absorb during a
similar trip to Mars."

Of particular interest are secondary particles.  Galactic cosmic
rays and solar energetic particles hit the walls of the spacecraft,
creating an inward spray of even more biologically dangerous neutrons
and atomic nuclei.  RAD will analyze the spray from the only realistic
place to make such measurements—inside the spaceship.

In this way, “RAD is a bridge between the science and exploration
sides of NASA,” says Hassler. “The two objectives are equally exciting.”

RAD was activated on Dec. 6th. Of the rover's ten
science instruments, it will be the only one active during the cruise to
Mars.  Daily transmissions to Earth will let Hassler and colleagues
monitor what's going on "out there."

"We're very excited about the possibility of more solar storms," he adds.

As important as RAD’s cruise phase measurements are, the
instrument’s primary mission doesn’t really begin until it lands on the
Red Planet. 

Mars has a very thin atmosphere and no global magnetic field to
protect it from space radiation.  Energetic particles reaching ground
level might be dangerous to life--both future human astronauts and
extant Martian microbes.  RAD will find out how much shielding human
explorers need on the surface of Mars.  RAD will also help researchers
estimate how far below ground a microbe might have to go to reach a
radiation “safe zone.” 

Solar storms are just for starters. Stay tuned to Science@NASA for the second installment of this story: Curiosity and the Habitability Mars.Author:Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit: Science@NASA

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Geminid Meteor Shower

By: Susie77, 1:05 AM GMT on December 14, 2011

From Spaceweather.com


GEMINID
METEOR SHOWER:
The Geminid meteor
shower peaks on Dec. 13th and 14th. Bright moonlight
will interfere with the display, but not obliterate
it. Forecasters expect observers with clear skies
to see as many as 40 meteors per hour. The best
time to look, no matter where you live, is between
10 pm local time on Tuesday, Dec. 13, and sunrise
on Wednesday, Dec. 14th. [full
story
] [meteor
radar
] [meteor
app
] [sky
map
] [Geminid images: #1]

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Mini Me! (Well, Mini-Us)

By: Susie77, 2:33 AM GMT on December 10, 2011



Is Vesta the "Smallest Terrestrial Planet?"

Play ScienceCast VideoJoin Mailing ListDec 9, 2011: NASA's Dawn spacecraft spent the last four years voyaging to asteroid Vesta – and may have found a planet.

Vesta was discovered over two hundred years ago but, until Dawn,
has been seen only as an indistinct blur and considered little more than
a large, rocky body. Now the spacecraft's instruments are revealing the
true complexity of this ancient world.

"We're seeing enormous mountains, valleys, hills, cliffs, troughs,
ridges, craters of all sizes, and plains," says Chris Russell, Dawn
principal investigator from UCLA. "Vestais not a simple ball of rock.
This is a world with a rich geochemical history. It has quite a story to
tell!"
Vesta
Like Earth and other terrestrial planets, Vesta has ancient
basaltic lava flows on the surface and a large iron core. It also has
tectonic features, troughs, ridges, cliffs, hills and a giant mountain.
False colors in this montage represent different rock and mineral types.
[more] [video]

In fact, the asteroid is so complex that Russell and members of his team are calling it the "smallest terrestrial planet."

Vesta has an iron core, notes Russell, and its surface features
indicate that the asteroid is "differentiated" like the terrestrial
planets Earth, Mercury, Mars, and Venus.
Draconids (signup)
Differentiation is what happens when the interior of an active
planet gets hot enough to melt, separating its materials into layers.
The light material floats to the top while the heavy elements, such as
iron and nickel, sink to the center of the planet.

Researchers believe this process also happened to Vesta.

The story begins about 4.57 billion years ago, when the planets of
the Solar System started forming from the primordial solar nebula. As
Jupiter gathered itself together, its powerful gravity stirred up the
material in the asteroid belt so objects there could no longer coalesce.
Vesta was in the process of growing into a full-fledged planet when
Jupiter interrupted the process.
Vesta
Like Earth and other terrestrial planets, Vesta is differentiated into layers.

Although Vesta’s growth was stunted, it is still differentiated like a true planet.

"We believe that the Solar System received an extra slug of
radioactive aluminum and iron from a nearby supernova explosion at the
time Vesta was forming," explains Russell. "These materials decay and
give off heat. As the asteroid was gathering material up into a big ball
of rock, it was also trapping the heat inside itself."

As Vesta’s core melted, lighter materials rose to the surface, forming volcanoes and mountains and lava flows.

"We think Vesta had volcanoes and flowing lava at one time,
although we've not yet found any ancient volcanoes there," says Russell.
"We're still looking. Vesta's plains seem similar to Hawaii's surface,
which is basaltic lava solidified after flowing onto the surface.

Vesta has so much in common with the terrestrial planets, should
it be formally reclassified from "asteroid" to "dwarf planet"?

"That's up to the International Astronomical Union, but at least
on the inside, Vesta is doing all the things a planet does."

If anyone asks Russell, he knows how he would vote.


Author: Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA

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Found! Earth's Sister.... maybe

By: Susie77, 7:51 PM GMT on December 05, 2011




Kepler Confirms First Planet in Habitable Zone of Sun-like Star

Dec 5, 2011:  NASA's Kepler mission has confirmed its first planet in the "habitable zone" of a distant sun-like star.
Kepler's First Planet (concept, 200px)

This artist's conception illustrates Kepler-22b, a planet known
to comfortably circle in the habitable zone of a sun-like star. [larger image]


The newly confirmed planet, Kepler-22b, is about 2.4 times the
radius of Earth. Scientists don't yet know if Kepler-22b has a
predominantly rocky, gaseous or liquid composition, but its discovery is
a step closer to finding Earth-like planets1.

The "habitable zone" of a planetary system refers to the band of
orbits where liquid water could exist on a planet’s surface. Kepler has
recently discovered more than 1,000 new planet candidates. Ten of these
candidates are near-Earth-size and orbit in the habitable zone of their
host star. Candidates require follow-up observations to verify they are
actual planets.


"This is a major milestone on the road to finding Earth's twin,"
said Douglas Hudgins, Kepler program scientist at NASA Headquarters in
Washington.

Kepler-22b is located 600 light-years away. While the planet is
larger than Earth, its orbit of 290 days around a sun-like star
resembles that of our world. The planet's host star belongs to the same
class as our sun, called G-type, although it is slightly smaller and
cooler.

Kepler discovers planets and planet candidates by measuring dips
in the brightness of more than 150,000 stars to search for planets that
cross in front, or "transit," the stars. Kepler requires at least three
transits to verify a signal as a planet.


"Fortune smiled upon us with the detection of this planet," said
William Borucki, Kepler principal investigator at NASA Ames Research
Center at Moffett Field, Calif., who led the team that discovered
Kepler-22b. "The first transit was captured just three days after we
declared the spacecraft operationally ready. We witnessed the defining
third transit over the 2010 holiday season."
Kepler's First Planet (layout, 558px)
This diagram compares our own solar system to Kepler-22, a star
system containing the first "habitable zone" planet discovered by NASA's
Kepler mission. The habitable zone is the sweet spot around a star
where temperatures are right for water to exist in its liquid form.
Liquid water is essential for life on Earth. [more]

The Kepler science team uses ground-based telescopes and the
Spitzer Space Telescope to review observations on planet candidates the
spacecraft finds. The star field that Kepler observes in the
constellations Cygnus and Lyra can only be seen from ground-based
observatories in spring through early fall. The data from these other
observations help determine which candidates can be validated as
planets.


Of the 54 habitable zone planet candidates reported in February
2011, Kepler-22b is the first to be confirmed. This milestone will be
published in The Astrophysical Journal.


The Kepler team is hosting its inaugural science conference at
Ames Dec. 5-9, announcing 1,094 new planet candidate discoveries. Since
the last catalog was released in February, the number of planet
candidates identified by Kepler has increased by 89 percent and now
totals 2,326. Of these, 207 are approximately Earth-size, 680 are super
Earth-size, 1,181 are Neptune-size, 203 are Jupiter-size and 55 are
larger than Jupiter.

The findings, based on observations conducted May 2009 to
September 2010, show a dramatic increase in the numbers of smaller-size
planet candidates.  Earth-size and super Earth-size candidates have
increased in number by more than 200 and 140 percent since February,
respectively. These new data suggest that planets one to four times the
size of Earth may be abundant in the galaxy.

So far, there are 48 planet candidates in their star's habitable
zone. While this is a decrease from the 54 reported in February, the
Kepler team has applied a stricter definition of what constitutes a
habitable zone in the new catalog, to account for the warming effect of
atmospheres, which would move the zone away from the star, out to longer
orbital periods.


"The tremendous growth in the number of Earth-size candidates
tells us that we're honing in on the planets Kepler was designed to
detect: those that are not only Earth-size, but also are potentially
habitable," said Natalie Batalha, Kepler deputy science team lead at San
Jose State University in San Jose, Calif.

 


Production Editor: Dr. Tony Phillips | Credit: Science@NASA

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December Sky-Watching Events

By: Susie77, 5:40 PM GMT on December 02, 2011


A total lunar eclipse, a close encounter between Mercury and the moon,
and a planetary tour de force are just some of the amazing sights
skywatchers can see this month. Here are the most exciting skywatching
targets for December 2011:

Moon Phases

Fri., December 2, 4:52 a.m. EST

First Quarter Moon








The First Quarter Moon rises around 1 p.m. local time, and sets around 1 a.m.

Saturday, Dec. 10, 9:36 a.m. EST

Full Moon

The full Moon of December is usually called the Oak Moon.

In Algonquian it is called Cold Moon. Other names are Frost Moon,
Winter Moon, Long Night’s Moon, and Moon Before Yule. In Hindi it is
known as Margashirsha Poornima. Its Sinhala (Buddhist) name is Unduvap
Poya. The Full Moon rises around sunset and sets around sunrise, the
only night in the month when the moon is in the sky all night long. The
rest of the month, the moon spends at least some time in the daytime
sky.

Saturday, Dec. 17, 7:48 p.m. EST

Last Quarter Moon

The Last or Third Quarter Moon rises around 11 p.m. and sets around
noon. It is most easily seen just after sunrise in the southern sky.

Saturday, Dec. 24, 1:06 p.m. EST

New Moon

The Moon is not visible on the date of New Moon because it is too close
to the sun, but can be seen low in the east as a narrow crescent a
morning or two before, just before sunrise. It is visible low in the
west an evening or two after New Moon.

Observing Highlights

Saturday, Dec. 10, dawn

Total Lunar Eclipse

A total lunar eclipse
will be seen in its entirety in eastern Asia, Australia, Oceania, and
Alaska. The moon will rise eclipsed in the early evening in Europe and
Africa, and set eclipsed just before dawn in western North America. The
graphic shows how it will look just before dawn in central California,
surrounded by first magnitude stars. [Photos: The Long Total Lunar Eclipse of June 2011]
Lunar Eclipse December 10, 2011 Sky Map
A
total lunar eclipse will occur at dawn on Saturday, Dec. 10, 2011. The
graphic shows how it will look just before dawn in central California,
surrounded by first magnitude stars.
CREDIT: Starry Night SoftwareView full size image

 

Thursday, Dec. 22, 12:30 a.m. EST

Solstice

It will be winter solstice
in the northern hemisphere, and summer solstice in the southern
hemisphere. On this day, the sun is at its farthest southern
declination, and is 6.5 degrees away from the center of the Milky Way.
This is exactly the same alignment as will occur on Dec. 21 2012, yet no
catastrophes have been predicted for this year, just as none will occur
next year. Because of the extreme difference in brightness between the
sun and the Milky Way, this alignment is observable only in a computer
simulation.
Winter Solstice Dec. 22, 2011 Sky Map
The
solstice will occur Thursday, Dec. 22, 2011. On this day, the sun is at
its farthest southern declination, and is 6.5 degrees away from the
center of the Milky Way.
CREDIT: Starry Night SoftwareView full size image

Thursday, Dec. 22, and Friday, Dec. 23, dawn

Close encounter between Mercury and the moon

The moon will be just to the right of Mercury on Dec. 22 (shown here) and just to the left of Mercury on Dec. 23.
December 22, 2011, Sky Map
On Thursday, Dec. 22, 2011, the moon will be just to the right of Mercury.
CREDIT: Starry Night SoftwareView full size image

Tuesday, Dec. 27, 10:52 p.m. EST

Jupiter satellite show

Three of Jupiter’s moons
will put on a fine show tonight. Callisto will be in an unusual
position due south of the planet because of the extreme tilt of the
plane of Jupiter's moons this year.

Europa will be moving off from in front of Jupiter on one limb while
its shadow begins a transit on the opposite limb. Ganymede, well off to
the right, will still be casting its shadow just below Europa. Finally,
the Great Red Spot will be perfectly placed right in the middle of all
this.
Jupiter and Moons Dec. 27, 2011 Sky Map
Three of Jupiter’s moons will be visible on Tuesday, Dec. 27, 2011.
CREDIT: Starry Night SoftwareView full size image

Planets

Mercury is well placed in the eastern sky before sunrise for the last half of the month.

Venus is low in the evening sky after sunset all
month. The waxing crescent moon will pass close to Venus on Monday, Dec.
26 and Tuesday, Dec. 27.

Mars spends all of December in the morning sky in Leo.
It now outshines nearby star Regulus and grows from 7 arcseconds wide
to 9 arcseconds during the month, large enough to reveal its polar cap
and dark surface markings in a 6-inch (150-mm) telescope. It is now
approaching magnitude 0, making it one of the brightest objects in the
morning sky.

Jupiter continues to be well placed in the evening sky
all month on the border between the constellations Aries and Pisces.
Jupiter and Venus are the brightest objects in the night sky other than
the moon.

Saturn is visible before dawn in the eastern sky. It now shines brighter than nearby star Spica.

Uranus is well placed in the early evening in Pisces all month.

Neptune is well placed in the early evening in Aquarius all month.

This article was provided to SPACE.com by Starry Night Education, the leader in space science curriculum solutions. Follow Starry Night on Twitter @StarryNightEdu.

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About Susie77

Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.

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