iPHONE VS
ANDROID! Actually, it doesn't matter which
phone you carry. Our cool, new app turns both smartphones
into field-tested satellite trackers. Learn
more. |
|
|
SEE
THE SECRET SPACE PLANE: Readers
in the USA and Canada, for the next week or so,
the US Air Force's "secret" X-37B
space plane will be making visible passes over many
North American towns and cities. Check the Simple
Satellite Tracker for viewing times--or turn
your cell phone into a space plane tracker. It's
simple.
EARTH
DODGES ANOTHER BULLET: Just as
sunspot 1105 was turning away from Earth on Sept.
8th, the active region erupted, producing a C3-class
solar flare (peak @ 2330 UT) and a fantastic prominence.
Here is a snapshot from the Solar Dynamics Observatory:
The eruption also hurled a bright coronal mass
ejection (CME) into space: SOHO
movie. The expanding cloud is heading into a
part of the solar system not currently occupied
by any planet--it's going to miss everything, including
Earth. If such a CME did hit Earth's magnetic field,
it would probably trigger strong geomagnetic storms.
Maybe next time...
Update #1: Two new movies of the
eruption are available from the Solar Dynamics Observatory--a
big picture
view in black-and-white and a spectacular
close-up in three extreme ultraviolet colors.
Update #2: NASA's STEREO-Ahead
spacecraft is stationed almost directly above sunspot
1105. A first-look
movie shows a shadowy "solar tsunami"
wave racing away from the blast site.
PURPLE
AURORAS: Auroras are dancing around
the Arctic Circle and some of them are purple. This
is how the sky looked on Sept. 8th over Bø, Norway:
"It's not often I get to see
purple auroras," says photographer Øystein
Lunde Ingvaldsen. "This was truly a fantastic
sight!"
Auroras get their
colors from specific atoms and molecules in
Earth's atmosphere. Green comes from oxygen molecules
excited by geomagnetic activity. Purple, on the
other hand, is usually a mixture of red and blue
emissions from molecular nitrogen. O2
and N2 were both revved up in Norway
last night!
More purple is possible tonight as
a solar wind stream continues to buffet Earth's
magnetic field. High-latitude sky watchers should
remain alert
for auroras.
NEW:
Sept.
2010 Northern Lights Gallery
[previous Septembers: 2009,
2008,
2007,
2006,
2005,
2004,
2002,
2001,
2000]
Potentially
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
finding
new
ones all the time.
On September 9, 2010 there were 1144 potentially hazardous asteroids.
Notes: LD means "Lunar
Distance."
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.
| |
The
official U.S. government space weather bureau |
| |
The
first place to look for information about sundogs,
pillars, rainbows and related phenomena. |
| |
Researchers
call it a "Hubble for the sun." SDO is the most
advanced solar observatory ever. |
| |
3D
views of the sun from NASA's Solar and Terrestrial
Relations Observatory |
| |
Realtime
and archival images of the Sun from SOHO. |
| |
from
the NOAA Space Environment Center |
| |
from
the National Solar Data Analysis Center |
