You are viewing the page for Sep. 17, 2012
  Select another date:
<<back forward>>
SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 398.6 km/sec
density: 2.2 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: B9
2212 UT Sep17
24-hr: C2
1406 UT Sep17
explanation | more data
Updated: Today at: 2259 UT
Daily Sun: 17 Sep 12
Solar activity is low. None of these sunspots are actively flaring. Credit: SDO/HMI
Sunspot number: 77
What is the sunspot number?
Updated 17 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 17 Sep 2012

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 4.9 nT
Bz: 3.1 nT south
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 17 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 17 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 17 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 %
25 %
SEVERE
10 %
15 %
 
Monday, Sep. 17, 2012
What's up in space
 

Thirty-five new items have just been added to our Meteorite Jewelry collection. Browse the Space Weather Store for something out of this world.

 
Meteorite jewelry

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.

AUTUMN LIGHTS: Northern autumn is only days away, and that means aurora season is underway. For reasons researchers don't fully understand, equinoxes are the best times to see Northern Lights--especially around the Arctic Circle. Aurora tour guide Chad Blakley photographed this first sign of autumn from Abisko National Park on Sweden on Sept 14th:

"The auroras were in the sky as soon as the sun went down, and they continued to glow well into the morning," says Blakley. "It was another great night in Abisko."

More autumn lights are in the offing as three solar wind streams are expected to buffet Earth's magnetic field, one after another, between Sept. 18th and 22nd. The long-range forecast includes a 15% chance of severe geomagnetic storms around the Artic Circle. Aurora alerts: text, voice.

Realtime Aurora Photo Gallery

PLASMA RAIN: The sun hasn't been flaring much lately, but there's more to solar activity than flares. For instance, on Saturday amateur astronomer Michael Buxton of Ocean Beach, CA, witnessed a dynamic 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.

Realtime Space Weather 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 17, 2012 there were 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
2009 LS
Nov 28
55.2 LD
--
1.1 km
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.
©2019 Spaceweather.com. All rights reserved.