Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.
By: Susie77, 20:31 GMT le 29 février 2012
See 5 Bright Planets in Night Sky—First Time in 8 Years
Find out when and where to see naked-eye objects this week.
By: Susie77, 17:19 GMT le 24 février 2012
Curiosity, the Stunt Double
Play ScienceCast VideoJoin Mailing List
Feb. 24, 2012:
With a pair of bug-eyes swiveling on a stalk nearly 8 feet off the
ground, the 6-wheeled, 1800-lb Mars rover Curiosity doesn’t look much like a human being. Yet, right now, the mini-Cooper-sized rover is playing the role of stunt double for NASA astronauts.
“Curiosity is riding to Mars in the belly of a spacecraft, where
an astronaut would be,” explains Don Hassler of the Southwest Research
Institute in Boulder, Colorado. “This means the rover experiences
deep-space radiation storms in the same way that a real astronaut
Curiosity doesn't look much like a human being, but the rover
turns out to be an excellent stunt double for real astronauts. [video]
Indeed, on Jan. 27th, 2012, Curiosity’s spacecraft was
hit by the most intense solar radiation storm since 2005. The event
began when sunspot AR1402 produced an X2-class solar flare. (On the
“Richter Scale of Solar Flares,” X-flares are the most powerful kind.)
The explosion accelerated a fusillade of protons and electrons to nearly
light speed; these subatomic bullets were guided by the sun’s magnetic
field almost directly toward Curiosity.
When the particles hit the outer walls of the spacecraft, they
shattered other atoms and molecules in their path, producing a secondary
spray of radiation that Curiosity both absorbed and measured.
“Curiosity was in no danger,” says Hassler. “In fact, we intended
all along for the rover to experience these storms en route to Mars.”
A photo of the Radiation Assessment Detector (RAD) in the laboratory. [more]
Unlike previous Mars rovers, Curiosity is equipped with a
Radiation Assessment Detector. The instrument, nicknamed “RAD,” counts
cosmic rays, neutrons, protons and other particles over a wide range of
biologically-interesting energies. RAD’s prime mission is to investigate
the radiation environment on the surface of Mars, but researchers have
turned it on early so that it can also probe the radiation environment on the way to Mars as well.
Curiosity’s location inside the spacecraft is key to the experiment.
“We have a pretty good idea what the radiation environment is like
outside,” says Hassler, who is the principal investigator for RAD.
“Inside the spacecraft, however, is still a mystery.”
Even supercomputers have trouble calculating exactly what happens
when high-energy cosmic rays and solar energetic particles hit the walls
of a spacecraft. One particle hits another; fragments fly; the
fragments themselves crash into other molecules.
“It’s very complicated. Curiosity is giving us a chance to actually measure what happens.”
Even when the sun is quiet, Curiosity is bombarded by a slow
drizzle of cosmic rays—high-energy particles accelerated by distant
black holes and supernova explosions. In the aftermath of the Jan. 27th
X-flare, RAD detected a surge of particles several times more numerous
than the usual cosmic ray counts. Hassler’s team is still analyzing the
data to understand what it is telling them about the response of the
spacecraft to the storm.
More X-flares will help by adding to the data set. Hassler expects
the sun to cooperate, because the solar cycle is trending upward toward
a maximum expected in early 2013.
As of February 2012, “we still have 6 months to go before we reach Mars. That’s plenty of time for more solar storms.”
A stunt double’s work is never done.
By: Susie77, 17:38 GMT le 22 février 2012
NASA Telescope Finds Elusive Buckyballs in Space07.22.10
By: Susie77, 14:02 GMT le 20 février 2012
Cold and Spellbinding: An Alignment of Planets in the Sunset Sky
Play ScienceCast VideoJoin Mailing List
Feb. 17, 2012:
Note to sky watchers: Put on your winter coats. What you’re about to
read might make you feel an uncontrollable urge to dash outside.
The brightest planets in the solar system are lining up in the
evening sky, and you can see the formation—some of it at least—tonight.
Go out at sunset and look west. Venus and Jupiter pop out of the
twilight even before the sky fades completely black. The two brilliant
planets surrounded by evening blue is a beautiful sight.
Amateur astronomer Göran Strand photographed Venus and Jupiter converging over Frösön, Sweden, on Feb.12, 2012. [video]
If you go out at the same time tomorrow, the view improves,
because Venus and Jupiter are converging. In mid-February they are
about 20 degrees apart. By the end of the month, the angle narrows to
only 10 degrees—so close that you can hide them together behind your
outstretched palm. Their combined beauty grows each night as the
distance between them shrinks.
A special night to look is Saturday, Feb. 25th, when the crescent Moon moves in to form a slender heavenly triangle with Venus, Jupiter and the Moon as vertices (sky map). One night later, on Sunday, Feb. 26th, it happens again (sky map).
This arrangement will be visible all around the world, from city and
countryside alike. The Moon, Venus and Jupiter are the brightest
objects in the night sky; together they can shine through urban lights,
fog, and even some clouds.
After hopping from Venus to Jupiter in late February, the Moon exits stage left, but the show is far from over.
In March, Venus and Jupiter continue their relentless convergence until, on March 12th and 13th, the duo lie only three degrees apart—a spectacular double beacon in the sunset sky (sky map). Now you’ll be able to hide them together behind a pair of outstretched fingertips.
There’s something mesmerizing about stars and planets bunched
together in this way—and, no, you’re not imagining things when it
happens to you. The phenomenon is based on the anatomy of the human
The fovea is responsible for our central, sharpest vision. [more]
"Your eye is a bit like a digital camera," explains optometrist
Dr. Stuart Hiroyasu of Bishop, California. "There's a lens in front to
focus the light, and a photo-array behind the lens to capture the image.
The photo-array in your eye is called the retina. It's made of rods and
cones, the organic equivalent of electronic pixels."
There’s a tiny patch of tissue near the center of the retina where
cones are extra-densely packed. This is called “the fovea.”
"Whatever you see with the fovea, you see in high-definition,"
Hiroyasu says. The fovea is critical to reading, driving, watching
television. The fovea has the brain's attention.
The field of view of the fovea is only about five degrees wide.
Most nights in March, Venus and Jupiter will fit within that narrow
cone. And when they do—presto! It’s spellbinding astronomy.
Standing outdoors, mesmerized by planets aligned in a late winter
sunset, you might just forget how cold you feel. Bring a coat anyway….
By: Susie77, 20:02 GMT le 16 février 2012
Europe Hammered by Winter, Is North America Next?
Feb 16, 2012: For the first half of this year's winter, the big news was warm temperatures and lack of snow. Ski resorts were covered in bare dirt, while January temperatures in southern California topped July highs.
Then, out of the blue, Europe got clobbered: Over the past two
weeks, temperatures in Eastern Europe have nose-dived to -30 degrees
Celsius (-22 degrees Fahrenheit). Blizzards and the bone-chilling cold
have resulted in the deaths of over 550 people so far, with rooftop-high
snow drifts trapping tens of thousands of villagers in their homes and
cutting off access to entire towns. It has even snowed as far south as
This map shows temperature anomalies for Europe and western
Russia from January 25 to February 1, 2012, compared to temperatures for
the same dates from 2001 to 2011. The anomalies are based on land
surface temperatures observed by the MODIS instrument on NASA’s Terra
NASA climatologist Bill Patzert of the Jet Propulsion Laboratory
explains what happened: "A couple of weeks ago, Mother Nature did an
about face. The tight polar vortex that had bottled up the cold arctic
air in the beginning of winter suddenly weakened. Cold air swept out of
Siberia and invaded Europe and the Far East."
The "tight polar vortex" is caused by the Arctic Oscillation (AO),
a see-sawing pressure difference between the Arctic and lower
latitudes. When the pressure difference is high, a whirlpool of air
forms around the North Pole. That’s what happened earlier this winter:
the whirlpool was more forceful, corralling the cold air and keeping it
nearer the pole.
An artist's concept of the Arctic Oscillation in its negative phase. [more] [video]
Now the vortex is weakening. With "the AO Index going negative,"
as an expert or weather-nerd might put it, cold air escapes from that
whirlpool and heads southward, resulting in the killing extremes now
plaguing the other half of the planet.
However, even the breakdown of the vortex cannot completely
account for the severity of the winter Europe is suddenly experiencing.
As strange as it sounds, some climatologists, among them Judah Cohen of
Atmospheric and Environmental Research in Massachusetts, attribute the
unusual cold to global warming. Cohen contends that since sea ice is
being melted by warmer temperatures in the Arctic, more moisture is
available for the atmosphere to pick up – and drop as snow. As a result,
Siberian snow cover has increased, and this snow cover has a cooling
effect which reaches East Asia and Europe.
"Cohen's research is cutting edge and could bring important
improvements to forecasting climate and weather over North America and
Europe," says Patzert. "Cohen and others are on the threshold of
understanding of how climate change affects the behavior of the Arctic
Patzert adds, however, that this winter is just one of many severe
winters that have changed European history. "Looking back, Mother
Nature has taken us on some very wild rides."
He cites the winter of 1683/84, when the Thames River in England
stayed frozen with a thick layer of ice for nearly two months, as an
If only Napolean had a weather satellite.... [more]
"And let’s not forget the frigid winter of 1812, when Napoleon's
Grande Armee was decimated by the extreme cold in Western Russia."
Patzert notes that European history would have been much different
if Napoleon had had a good meteorologist on his staff and some NASA
satellites to warn him about what he was marching into.
"And the turning point of World War II occurred in 1941, when Germany’s forces were nearly frozen in place," he adds.
There are many other examples2, and climate change can't be blamed for all of them.
"There's always going to be some natural variability. Every
episode of high temperatures or extreme cold isn't climate change.
Sometimes it's just weather!"
The weakening Arctic Oscillation could soon bring a return of
winter to North America as well, although Patzert doesn't expect it to
be as severe as what's happening on the other side of the Atlantic.
Is there any relief in sight for Europe?
"The good news is that this crippling cold snap arrived
mid-winter. With the vernal equinox less than six weeks away, this AO
episode will become muted – hopefully."
Hang on till Spring."
By: Susie77, 15:58 GMT le 13 février 2012
What happens when we fight two unnecessary and unfunded wars, while lowering taxes for the wealthy at the same time. :(
U.S. President Barack Obama will ask Congress for $17.7 billion for
NASA for 2013, an amount that would leave the agency funded at its
lowest level in four years, according to sources familiar with the
forthcoming budget proposal.
NASA’s planetary science division would shoulder a heavy share of the cut. Under the president’s proposal, its budget would drop from $1.5 billion to $1.2 billion, a 20 percent reduction.
Due on Capitol Hill Feb. 13, the $17.7 billion NASA budget proposal
represents only a slight reduction from the $17.8 billion Congress approved in November
for 2012. But compared to the $18.7 billion Obama penciled in for 2013
in the five-year budget he sent Congress this time last year, it
represents a 5 percent cut.
Things could have been worse. According to a source familiar with the
Obama administration’s internal budget deliberations, the White House
Office of Management and Budget asked the agency last fall to submit
budget proposals for three scenarios: a 5 percent cut, a 10 percent cut
and a 15 percent cut, relative to the outyear spending plan submitted
last year. [Photos: President Obama and NASA]
43 ° F