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Solar wind
speed: 381.3 km/sec
density: 5.1 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: M6
2158 UT Dec31
24-hr: M6
2158 UT Dec31
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 31 Dec 13
Sunspots AR1934 and AR1936 have 'beta-gamma-delta' magnetic fields that harbor energy for X-class solar flares. Credit: SDO/HMI
Sunspot number: 93
What is the sunspot number?
Updated 31 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

31 Dec 2013

The Radio Sun
10.7 cm flux: 143 sfu
explanation | more data
Updated 31 Dec 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 5.8 nT
Bz: 1.3 nT south
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 30 Dec 13
Solar wind flowing from the indicated coronal hole could reach Earth on Jan 2-3. Credit: SDO/AIA. posts 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: 12-31-2013 13:55:02
NOAA Forecasts
Updated at: 2013 Dec 31 2200 UTC
0-24 hr
24-48 hr
40 %
40 %
10 %
10 %
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 31 2200 UTC
0-24 hr
24-48 hr
20 %
30 %
05 %
10 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
15 %
30 %
25 %
25 %
40 %
Tuesday, Dec. 31, 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

NEW YEARS AT THE EDGE OF SPACE: On New Year's Day, Jan. 1st, the students of Earth to Sky Calculus will launch a space weather balloon to the stratosphere (~120,000 feet altitude). It's part of their ongoing program to monitor energetic solar particles at the edge of space. Would you like to support their flight? You can! For only $49.95 the students will send a picture of your choice along for the ride. The group has previously photographed cupcakes, shoes, US presidents, ad banners and telescopes at the edge of space. Your personal New Year's greeting card could be next. Contact Dr. Tony Phillips for more information.

SIGNIFICANT FLARE: It could be the last solar flare of 2013. At 21:58 UT on Dec. 31st, sunspot AR1936 erupted and produced a strong M6-class solar flare. NASA's Solar Dynamics Observatory recorded the extreme ultraviolet flash:

A movie of the explosion shows a dark filament of plasma flying away from the blast site. Indeed, the explosion probably hurled a coronal mass ejection (CME) into space. The CME, if there is one, could deliver a glancing blow to Earth's magnetic field later this week. Stay tuned for updates as more data become available. Solar flare alerts: text, voice.

MUST-SEE SUNSET PHENOMENON: Like the Moon, Venus has phases, and this week it is a whisper-thin crescent. The phenomenon is easy to observe. Venus is so bright, you can see it at sunset even before the sky fades to black. To the naked eye, Venus looks like an unusually luminous star. A pair of binoculars or a small telescope reveals the planet's crescent shape.

This composite image shows how Venus looks to the naked eye and through a telescope:

The sunset self-portrait was made by Jean-Baptiste Feldmann of Nuits-Saint-Georges, France. The telescopic inset was recorded by Sylvain Weiller of Saint Rémy-lès-Chevreuse, France. "The crescent is becoming very thin," says Weiller. "Venus no longer looks like a planet. It's more like a solar eclipse!"

Venus looks the way it does because it is turning its night side toward Earth. Today, only a 4% sliver of Venus's dayside is visible. On Jan. 11th, Venus will pass almost directly between Earth and the sun. At that moment, called "inferior conjunction," the sliver will almost completely disappear--so catch it now!

Realtime Venus Photo Gallery

COMING SOON--THE FIRST AURORAS OF 2014: Magnetic fields in the sun's northern hemisphere have opened up, creating a vast hole in the sun's atmosphere--a coronal hole. NASA's Solar Dynamics Observatory is monitoring the UV-dark gap:

Coronal holes are places where magnetic fields threading through the sun's atmosphere spread apart and allow solar wind to escape. A stream of solar wind flowing from this particular coronal hole could reach Earth on Jan. 2-3, possibly sparking polar geomagnetic storms. The first auroras of 2014 are in the offing. Solar flare alerts: text, voice.

Realtime Space Weather Photo Gallery

Realtime Aurora Photo Gallery

Realtime Comet 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. 31, 2013, the network reported 6 fireballs.
(4 sporadics, 1 December Leonis Minorid, 1 alpha Hydrid)

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 31, 2013 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 YD29
Dec 28
6.1 LD
24 m
2013 YL2
Jan 3
3.6 LD
102 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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