COMET SNOWSTORM ENGULFS HARTLEY 2:
Researchers have released new and beautiful photos
of an unprecedented snowstorm raging around Comet
Hartley 2. "We've never seen anything like
it," says science team leader Michael A'Hearn
of the University of Maryland. Get the full
story from Science@NASA.
BLUE MOON: According to modern
folklore, a Blue Moon is the second full Moon in
a calendar month. The next Blue Moon to fit this
description will come on August 31, 2012. Do we
really have to wait so long? There is an older
definition that says the next Blue Moon is this
weekend. To prepare for the event, Stefano
De Rosa snapped this picture of the Moon waxing
full over Turin, Italy:
The Moon is full on Nov. 21st. Usually
there are only three full Moons in a season, but
this Fall there will be four. The full Moon of Nov.
21st is the third of those four. According to old
editions of the Maine Farmer’s Almanac, that makes
it a Blue Moon. Confused? No wonder the modern definition
is so much simpler.
"We have bad weather forecast
for the 21st," says De Rosa, "so I took
my old-fashioned Blue Moon photo on the 19th instead.
It might not be truly blue, but the Moon looked
great anyway rising alongside the Superga church
while another wonder from the sky was joining the
Readers, be alert on Sunday night
for a Blue Moon of your own.
more images: from
Saied Bahrami Nejad of Kerman, Iran; from
Guillaume Cannat of Prades-le-lez, France; from
Tom Wagner of Waterloo, Iowa
RECAP: Earth is exiting a thicket
of debris from Comet Tempel-Tuttle, source of the
annual Leonid meteor shower. According to international
counts, the shower crested on Nov. 17th and
18th with a peak rate of 20 meteors per hour. Compared
to, say, the Leonid storms of a decade ago, it was
not an impressive display--that is, unless you added
it up for five nights in a row:
"These are all the Leonid fireballs I recorded
from Nov. 13th to Nov. 18th," says Jim Gamble,
who operates an
all-sky camera in El Paso, Texas. "In total,
there were 16 Leonids of magnitude -3 or brighter."
Considering that Earth missed the densest part of
the Leonid debris stream in 2010, more than a dozen
fireballs is a good haul.
A bigger display is coming: In early December,
Earth will enter a cloud of debris from extinct
comet Phaethon, setting off the annual Geminid meteor
shower. On peak night, Dec. 14th, forecasters expect
as many as 100 meteors per hour, five times greater
than the waning Leonids. Stay tuned!
more images: from
Yuichi Takasaka of Gingolx (Kincolith), British
Columbia, Canada; from
Thomas Kerns of Homer, Alaska; from
Yaron Eini of Jerusalem, Israel;
2010 Aurora Gallery
[previous Novembers: 2009,
Hazardous Asteroids (PHAs
are space rocks larger than approximately 100m that can come
closer to Earth than 0.05 AU. None of the known PHAs is on
a collision course with our planet, although astronomers are
all the time.
November 20, 2010 there were 1164
potentially hazardous asteroids.
Notes: LD means "Lunar
1 LD = 384,401 km, the distance between Earth and the Moon.
1 LD also equals 0.00256 AU. MAG is the visual magnitude
of the asteroid on the date of closest approach.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO is the most
advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather