You are viewing the page for Sep. 16, 2012
  Select another date:
<<back forward>>
SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 435.1 km/sec
density: 0.4 protons/cm3
explanation | more data
Updated: Today at 2342 UT
X-ray Solar Flares
6-hr max: B2
2212 UT Sep16
24-hr: B3
0442 UT Sep16
explanation | more data
Updated: Today at: 2259 UT
Daily Sun: 16 Sep 12
Solar activity is low. None of these sunspots are actively flaring. Credit: SDO/HMI
Sunspot number: 53
What is the sunspot number?
Updated 16 Sep 2012

Spotless Days
Current Stretch: 0 days
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days

Update 16 Sep 2012


The Radio Sun
10.7 cm flux: 101 sfu
explanation | more data
Updated 16 Sep 2012

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 3.5 nT
Bz: 0.8 nT south
explanation | more data
Updated: Today at 2345 UT
Coronal Holes: 16 Sep 12
Solar wind flowing from these three coronal holes will buffet Earth's magnetic field, one after another, from Sept. 18th through Sept. 22nd. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2012 Sep 16 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
10 %
10 %
CLASS X
01 %
01 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2012 Sep 16 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
20 %
15 %
MINOR
20 %
15 %
SEVERE
10 %
05 %
 
Sunday, Sep. 16, 2012
What's up in space
 

Listen to radar echoes from satellites and meteors, live on listener-supported Space Weather Radio.

 
Spaceweather Radio is on the air

QUIET SUN: Solar activity is low. NOAA forecasters say the chance of an M-class flare today is no more than 10%. An X-flare is even less likely: less than 1%. No strong flares are in the offing.

PLASMA RAIN: Despite the quiet, there has been something to see on the sun this weekend. Yesterday amateur astronomer Michael Buxton of Ocean Beach, CA, witnessed an episode of "plasma rain" on the sun's western limb. Click on the arrow to set the shower in motion:

The movie,which Buxton assembled from a series of 1 minute exposures taken over a 2 hour period on Sept. 15th, shows Moon-sized "droplets" of plasma swirling and falling along magnetic field lines from the sun's atmosphere to the sun's surface. That's how it rains on the sun.

This storm cloud, aka "prominence", has since rained out. The western limb is clear and sunny again.

NOT AURORAS: For the past week, solar wind has been buffeting Earth's magnetic field, turning skies around the Artic Circle beautiful shades of green. But not every green sky is caused by the aurora borealis. On Friday night, for example, pilot Brian Whittaker was flying 34,000 feet over the Atlantic Ocean when he witnessed verdant hues caused by a completely different phenomenon--airglow. Here is the picture he took from the cockpit window:

"A dark and moonless night away from all lights allowed a great view of this textured patch of airglow," says Whittaker. "The illumination was faint, but it could be seen especially in contrast to the dark ocean abyss below!"

Although airglow resembles the aurora borealis, its underlying physics is different. Airglow is caused by an assortment of chemical reactions in the upper atmosphere. During the day, ultraviolet radiation from the sun ionizes atoms and breaks apart molecules. At night, the atoms and molecules recombine, emitting photons as they return to normal. This process produces an aurora-like glow visible on very dark nights.

Because the Moon is new on Sept. 15th, tonight is a good night to spy this phenomenon. Get away from city lights, if you can, and take a look!

Realtime Space Weather Photo Gallery


Realtime Aurora Photo Gallery


Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]

  Near Earth Asteroids
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 16, 2012 there were 1330 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2012 QG42
Sep 14
7.4 LD
--
310 m
2012 QC8
Sep 14
22.7 LD
--
1.0 km
2012 RK15
Sep 24
8.2 LD
--
88 m
1998 UO1
Oct 4
60.1 LD
--
2.1 km
2005 GQ21
Oct 12
77 LD
--
1.0 km
1998 ST49
Oct 18
28.7 LD
--
1.3 km
1991 VE
Oct 26
34 LD
--
1.1 km
2001 CV26
Oct 30
68 LD
--
2.4 km
2007 PA8
Nov 5
16.8 LD
--
2.4 km
2010 JK1
Nov 25
9.3 LD
--
56 m
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.
  Essential web links
NOAA Space Weather Prediction Center
  The official U.S. government space weather bureau
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar Dynamics Observatory
  Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.
STEREO
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Heliophysics
  the underlying science of space weather
Trade Show Displays
   
  more links...
©2010 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2013 Spaceweather.com. All rights reserved.