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, 11:31 PM GMT on September 23, 2011
RE-ENTRY UPDATE: NASA's UARS satellite
is making its last orbits around Earth. Orbital
elements published today by the US Strategic Command
suggest that re-entry could occur during the early
hours of Saturday morning. "For now, it looks
like 00:00 - 04:00 UTC on Sept. 24,"
says satellite tracking expert Ted Molczan, "but
it could well happen even later. UARS will pass
over North America and Europe several times during
this period, but it will spend most of its time
over oceans and sparsely populated land." Stay
tuned for updates and meanwhile keep
an eye out for the doomed satellite. [latest
The Federal Aviation Administration
has issued the following Notice to Airmen
(NOTAM): "Aircraft are advised that
a potential haard may occur due to reentry of satellite
UARS into Earth's atmosphere. FAA is working with
the Department of Defense and NASA to ensure the
most current re-entry information is provided to
operators as quickly as possible. Further NOTAMS
will be issued if specific information becomes available
indicating a United States airspace impact. It is
critical that all pilots/flight crew members report
any fallinf space debris to the appropriate ATC
facility. The Domestic Events Network telephone
202-493-5107 is the FAA coordination facility. CREATED:
23 SEP 18:33 2011"
By: Susie77, 1:21 PM GMT on September 22, 2011
Last week we had a moderate (KP6) geomagnetic storm. ISS crew captured the aurora australis for our viewing pleasure:
Sorry for not making this a clickable link. WU has done something with the formatting of blog posts so that feature no longer works with the browser I use.
By: Susie77, 8:10 PM GMT on September 19, 2011
The Secret Lives of Solar Flares
Play ScienceCast VideoJoin Mailing ListSept. 19, 2011: One hundred and fifty two years ago, a man in England named Richard Carrington discovered solar flares.
Sunspots sketched by R. Carrington on Sept. 1, 1859. © R. Astronomical Society. [more]
It happened at 11:18 AM on the cloudless morning of Thursday,
September 1st, 1859. Just as usual on every sunny day, the 33-year-old
solar astronomer was busy in his private observatory, projecting an
image of the sun onto a screen and sketching what he saw. On that
particular morning, he traced the outlines of an enormous group of
sunspots. Suddenly, before his eyes, two brilliant beads of white light
appeared over the sunspots; they were so bright he could barely stand to
look at the screen.
Carrington cried out, but by the time a witness arrived minutes
later, the first solar flare anyone had ever seen was fading away.
It would not be the last. Since then, astronomers have recorded
thousands of strong flares using instruments ranging from the simplest
telescopes in backyard observatories to the most complex spectrometers
on advanced spacecraft. Possibly no other phenomenon in astronomy has
been studied as much.
After all that scrutiny, you might suppose that everything about
solar flares would be known. Far from it. Researchers recently
announced that solar flares have been keeping a secret.
“We’ve just learned that some flares are many times stronger than
previously thought,” says University of Colorado physicist Tom Woods who
led the research team. “Solar flares were already the biggest
explosions in the solar system—and this discovery makes them even
Click to view a ScienceCast video about the late phase of solar flares. [Youtube]
NASA’s Solar Dynamics Observatory (SDO), launched in February
2010, made the finding: About 1 in 7 flares experience an
“aftershock.” About ninety minutes after the flare dies down, it
springs to life again, producing an extra surge of extreme ultraviolet
“We call it the ‘late phase flare,’” says Woods. “The energy in
the late phase can exceed the energy of the primary flare by as much as a
factor of four.”
What causes the late phase? Solar flares happen when the magnetic
fields of sunspots erupt—a process called “magnetic reconnection.” The
late phase is thought to result when some of the sunspot’s magnetic
loops re-form. A diagram prepared by team member Rachel Hock of the University of Colorado shows how it works.
The extra energy from the late phase can have a big effect on
Earth. Extreme ultraviolet wavelengths are particularly good at heating
and ionizing Earth’s upper atmosphere. When our planet’s atmosphere is
heated by extreme UV radiation, it puffs up, accelerating the decay of
low-orbiting satellites. Furthermore, the ionizing action of extreme UV
can bend radio signals and disrupt the normal operation of GPS.
SDO was able to make the discovery because of its unique ability
to monitor the sun’s extreme UV output in high resolution nearly 24
hours a day, 7 days a week. With that kind of scrutiny, it’s tough to
keep a secret--even one as old as this.
The original research of Woods et al may be found in the Oct. 1, 2011, issue of the Astrophysical Journal.
Author: Dr. Tony Phillips | Credit: Science@NASA
By: Susie77, 7:50 PM GMT on September 16, 2011
Cool Video: Dawn Flies Around Vesta
Sept. 16, 2011: A new video from NASA's Dawn spacecraft takes us on a flyover above the surface of the giant asteroid Vesta.
The data obtained by Dawn's framing camera will help scientists
determine the processes that formed Vesta's striking features. It will
also help Dawn mission fans all over the world visualize this mysterious
world, which is the second most massive object in the main asteroid
belt. Click to play.
The voice of Carol Raymond, Dawn deputy principal investigator, narrates this unique fly-around of the giant asteroid. [video]
You'll notice in the video that Vesta is not entirely lit up.
There is no light in the high northern latitudes because, like Earth,
Vesta has seasons. Currently it is northern winter on Vesta, and the
northern polar region is in perpetual darkness. When we view Vesta's
rotation from above the south pole, half is in darkness simply because
half of Vesta is in daylight and half is in the darkness of night .
Another distinct feature seen in the video is a massive circular
structure in the south pole region. Scientists were particularly eager
to see this area close-up, since NASA's Hubble Space Telescope first
detected it years ago. The circular structure, or depression, is several
hundreds of miles, or kilometers, wide, with cliffs that are also
several miles high. One impressive mountain in the center of the
depression rises approximately 9 miles (15 kilometers) above the base of
this depression, making it one of the highest elevations on all known
bodies with solid surfaces in the solar system.
The collection of images, obtained when Dawn was about 1,700 miles
(2,700 kilometers) above Vesta's surface, was used to determine its
rotational axis and a system of latitude and longitude coordinates. One
of the first tasks tackled by the Dawn science team was to determine the
precise orientation of Vesta's rotation axis relative to the celestial
The zero-longitude, or prime meridian, of Vesta was defined by the
science team using a tiny crater about 1,640 feet (500 meters) in
diameter, which they named "Claudia," after a Roman woman during the
second century B.C. Dawn's craters will be named after the vestal
virgins-the priestesses of the goddess Vesta, and famous Roman women,
while other features will be named for festivals and towns of that era.
Stay tuned for more.
Production Editor: Dr. Tony Phillips | Credit: Science@NASA
By: Susie77, 8:32 PM GMT on September 09, 2011
UARS Re-Entry Overview
NASA's Upper Atmosphere Research Satellite, or UARS,
is expected to re-enter Earth's atmosphere in late September or early
October 2011, almost six years after the end of a productive scientific
life. Although the spacecraft will break into pieces during re-entry,
not all of it will burn up in the atmosphere.
The risk to
public safety or property is extremely small, and safety is NASA's top
priority. Since the beginning of the Space Age in the late-1950s, there
have been no confirmed reports of an injury resulting from re-entering
space objects. Nor is there a record of significant property damage
resulting from a satellite re-entry.
It is too early to say
exactly when UARS will re-enter and what geographic area may be
affected, but NASA is watching the satellite closely and will keep you
informed. Visit this page for updates on the satellite's orbital track
and predicted re-entry date.
› Re-Entry and Risk Assessment (498 KB PDF)
› Frequently Asked Questions: Orbital Debris
NASA will post updates weekly until four days before the anticipated
re-entry, then daily until about 24 hours before re-entry, and then at
about 12 hours, six hours and two hours before re-entry. The updates
will come from the Joint Space Operations Center of U.S. Strategic
Command at Vandenberg Air Force Base, Calif., which works around the
clock detecting, identifying and tracking all man-made objects in Earth
orbit, including space junk.
The actual date of re-entry is
difficult to predict because it depends on solar flux and the
spacecraft's orientation as its orbit decays. As re-entry draws closer,
predictions on the date will become more reliable.
As of Sept.
8, 2011, the orbit of UARS was 152 miles by 171 miles (245 km by 275 km)
with an inclination of 57 degrees. Because the satellite's orbit is
inclined 57 degrees to the equator, any surviving components of UARS
will land within a zone between 57 degrees north latitude and 57 degrees
south latitude. It is impossible to pinpoint just where in that zone
the debris will land, but NASA estimates the debris footprint will be
about 500 miles long.
If you find something you think may be a
piece of UARS, do not touch it. Contact a local law enforcement official
By: Susie77, 8:18 PM GMT on September 08, 2011
NASA’s Cassini orbiter snaps unbelievable picture of SaturnBy Mike Wehner, Tecca | Today in Tech – 5 hrs ago
By: Susie77, 5:45 PM GMT on September 07, 2011
RADIO BURSTS: This week's sharp
increase in solar activity has turned the sun into
a radio transmitter. Bursts of shortwave static
are coming from the unstable magnetic canopy of
sunspot 1283. Yesterday in New Mexico, amateur radio
astronomer Thomas Ashcraft recorded some samples
at 21 MHz: listen.
Radio listeners should remain alert for this
kind of solar activity as sunspot 1283 continues
By: Susie77, 10:59 PM GMT on September 04, 2011
I apologize in advance for no longer being able to post a hot link. WU changed stuff. I hate change. Enjoy this article anyways, and your weekend also!
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.