AURORA ALERTS: Did you miss the Northern Lights? Next time
get a wake-up call from Space
COMET: A newly-discovered comet
is diving toward the sun. Chinese comet hunter Bo
Zhou found it on Oct. 19th in SOHO coronagraph images.
The comet is faint now, but it should brighten in
the hours ahead as it heats up. To see it, first
finder chart, then play the latest
movie. That tadpole is a doomed comet. Updates
will be posted as the view improves.
METEOR SHOWER: Earth is entering
a broad stream of debris from Halley's Comet, and
this is causing the annual Orionid meteor shower.
"The best time to look is during the hours
before dawn on Thursday, Oct. 21st, and again on
Friday, Oct 22nd," advises Bill Cooke of NASA's
Meteoroid Environment Office. "Unfortunately,
we have a bright Moon this year. Even so, I'd expect
some bright Orionids to shine through the moonlight."
An all-sky camera at the University of Western Ontario
recorded this early Orionid fireball on Oct. 18th:
Orionid meteors stream from the elbow of Orion
the Hunter: sky
map. Because the shower's radiant point is close
to the celestial equator, sky watchers in both hemispheres
can enjoy the show. Moonlit meteor rates will probably
be around a dozen per hour.
Radar rates could be much higher. The US Air Force
Space Surveillance Radar in Texas is scanning the
skies for satellites, space junk, and meteoroids.
When an Orionid passes overhead--ping!--there
is an echo. Moonlight does not interfere with this
method of meteor observing, so it's perfect for
this year's Orionids. Tune into Spaceweather
Radio for live echoes.
Orionid images: from
John Chumack of Dayton, Ohio; from
Calvin Hall of Knik Valley, near Palmer Alaska;
Martin Popek of Nýdek, Czech republic
TO SEE COMET HARTLEY: For backyard
stargazers, now is the best time to see green Comet
103P/Hartley 2 as it approaches Earth for an 11-million-mile
close encounter on Oct. 20th. Set your alarm for
the dark hours before dawn, go outside, and look
straight up. You will find Hartley 2 not far from
the bright star Capella: sky
map. Although the comet is barely visible to
the unaided eye, it is easy to find in binoculars
and looks great through a backyard telescope.
"I observed Comet Hartley 2 at dawn on October
20, 2010, at its closest approach to Earth,"
says amateur astronomer Alan Dyer, who sends this
picture from a dark-sky site near Cluny, Alberta,
"Apart from the blue-green color, this view
matches what the comet looked like visually through
large binoculars — a round fuzzball," says
Many readers have asked, why is the comet green?
Answer: Hartley 2's green color comes from the gases
that make up its Jupiter-sized atmosphere. Jets
spewing from the comet's nucleus contain cyanogen
(CN: a poisonous gas found in many comets) and diatomic
carbon (C2). Both substances glow green
when illuminated by sunlight in the near-vacuum
NASA scientists say
103P/Hartley 2 is one of the most active comets
they've seen, with copious outgassing from jets
in the nucleus. Amateur astronomers are encouraged
to monitor the action and submit their images here.
more images: from
Doug Zubenel near Onaga, Kansas.; from
Paul Klauninger of Marathon, Ontario, Canada;
Jimmy Westlake of Stagecoach, Colorado; from
Nick Howes of Cherhill, Wiltshire, UK; from
Abe Schwartz of San Juan, Puerto Rico; from
Dr Paolo Candy of Ci.A.O. Cimini Astronomical
Observatory - Italy; from
John Chumack of Dayton, Ohio; from
Keith Johnson of Durham, England,UK; from
Joao Porto of Ponta Delgada, Azores islands,
2010 Aurora Gallery
[previous Octobers: 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.
October 20, 2010 there were 1155 potentially
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