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Solar wind
speed: 343.6 km/sec
density: 1.7 protons/cm3
explanation | more data
Updated: Today at 2346 UT
X-ray Solar Flares
6-hr max: C6
2037 UT Dec04
24-hr: C6
0057 UT Dec04
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 03 Dec 13
Sunspot AR1909 has a 'beta-gamma' magnetic fields that harbor energy for M-class solar flares. Credit: SDO/HMI
Sunspot number: 97
What is the sunspot number?
Updated 04 Dec 2013

Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
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

04 Dec 2013

The Radio Sun
10.7 cm flux: 136 sfu
explanation | more data
Updated 04 Dec 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 4.6 nT
Bz: 2 nT south
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 04 Dec 13
A stream of solar wind flowing from the indicated coronal hole should reach Earth on Dec. 7-8. Credit: SDO/AIA. is now posting daily satellite images of noctilucent clouds (NLCs), which hover over Earth's poles at the edge of space. The data come from NASA's AIM spacecraft. The north polar "daisy" pictured below is a composite of near-realtime images from AIM assembled by researchers at the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).
Noctilucent Clouds
Switch view: Europe, USA, Asia, Polar
Updated at: 12-04-2013 13:55:02
NOAA Forecasts
Updated at: 2013 Dec 04 2200 UTC
0-24 hr
24-48 hr
15 %
15 %
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: 2013 Dec 04 2200 UTC
0-24 hr
24-48 hr
05 %
15 %
01 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
15 %
20 %
05 %
20 %
Wednesday, Dec. 4, 2013
What's up in space

When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms.

Northern Lights - a Guide

STILL QUIET: The sun's southern hemisphere is peppered with sunspots, but none of them is actively flaring. Solar activity remains low. NOAA forecasters estimate a 25% chance of M-class solar flares and a scant 1% chance of X-flares on Dec. 4th. Solar flare alerts: text, voice

GEMINID METEOR SHOWER: Earth is entering a stream of debris from rock comet 3200 Phaethon, source of the annual Geminid meteor shower. Our planet is just dipping into the outskirts of the debris zone now, so visual meteor rates are low. Nevertheless, the Canadian Meteor Orbit Radar (CMOR) is starting to pick up echoes from Geminid meteoroids. This Dec. 4th radar map shows a concentration of activity in the constellation Gemini:

"The Geminids, still ten days from their maximum, are very clearly visible in the latest CMOR data," reports Prof. Peter Brown of the University of Western Ontario, which operates the radar.

In the radar map, the Geminid radiant is labeled 'GEM.' A second nearby radiant labeled 'NOO' marks the location of the November omega Orionids, a minor shower that peaks in early December.

The Geminids won't peak until Dec. 13-14 when Earth passes through the core of the debris stream, but Brown thinks observers should start looking now. "Glare from the nearly-full Moon will interfere with the Geminid's maximum in mid-December," he says. "This week, however, the Moon is new. Observers should be starting to see activity from this very strong shower." Observing tip: The best time to look is during the hours between midnight and dawn when the constellation Gemini is high in the sky. Meteor alerts: text, voice

RARE V-SHAPED SUN HALO: At the end of Thanksgiving Day when the sun was setting over Sumterville, Florida, Paula Phillips took a break from her meal, stepped outside and saw something odd--a pair of luminous 'Vs' in the deepening twilight:

"I've never seen anything like this before," says Phillips. "I photographed the phenomenon with a simple small Samsung camera."

They're sun halos, caused by sunlight shining through ice crystals. Atmospheric optics expert Les Cowley explains:

"These two ‘V’ shaped halos, one rare and one common, change shape dramatically as the sun climbs," he says. "Near sunrise or sunset is the only time to catch them like this. The lower ‘V’ is an upper tangent arc from horizontal hexagonal prisms of ice. The upper one is a rare sunvex Parry arc from similar crystals that - strangely – are fixed so that two prism faces are always horizontal. In the full-sized image, we also see just a trace of a 22o halo and stretching upwards from the sun a sun pillar."

"I find it odd that I saw this in Florida!" continues Phillips. Yet Florida has ice crystal, too. The atmosphere 5 to 10 km above the Sunshine State is always cold enough for water to freeze.

"Florida and other warm places get plenty of halos--some of them exceedingly rare," says Cowley. "Look for them everywhere, winter and summer."

Realtime Space Weather Photo Gallery

Realtime All-Comet Photo Gallery

Realtime Aurora Photo Gallery

  All Sky Fireball Network
Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on

On Dec. 4, 2013, the network reported 15 fireballs.
(12 sporadics, 2 sigma Hydrids, 1 Geminid)

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]

  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 December 4, 2013 there were 1444 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2013 WH25
Nov 29
0.4 LD
5 m
2013 WV43
Dec 3
9.5 LD
18 m
2011 YD29
Dec 28
6.1 LD
24 m
2007 SJ
Jan 21
18.9 LD
1.9 km
2012 BX34
Jan 28
9.6 LD
13 m
2006 DP14
Feb 10
6.2 LD
730 m
2000 EM26
Feb 18
8.8 LD
195 m
2000 EE14
Mar 6
64.6 LD
1.8 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.
  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
  the underlying science of space weather
Space Weather Alerts
  more links...
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