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Solar wind
speed: 359.2 km/sec
density: 2.3 protons/cm3
explanation | more data
Updated: Today at 2348 UT
X-ray Solar Flares
6-hr max: M6
2158 UT Dec18
24-hr: M6
2158 UT Dec18
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 18 Dec 14
Sunspots AR2241 and AR2242 have delta-class magnetic fields that harbors energy for X-class solar flares. Credit: SDO/HMI
Sunspot number: 154
What is the sunspot number?
Updated 18 Dec 2014

Spotless Days
Current Stretch: 0 days
2014 total: 1 day (<1%)
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%)

Update 18 Dec

The Radio Sun
10.7 cm flux: 192 sfu
explanation | more data
Updated 18 Dec 2014

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 7.4 nT
Bz: 5.1 nT south
explanation | more data
Updated: Today at 2349 UT
Coronal Holes: 18 Dec 14
There are no large coronal holes on the Earthside of he sun. Credit: SDO/AIA.
Noctilucent Clouds As of Nov. 22, 2014, the season for southern hemisphere noctilucent clouds is underway. The south polar "daisy" pictured below is a composite of near-realtime images from NASA's AIM spacecraft.
Switch view: Ross Ice Shelf, Antarctic Penninsula, East Antarctica, Polar
Updated at: 12-18-2014 14:55:04
NOAA Forecasts
Updated at: 2014 Dec 18 2200 UTC
0-24 hr
24-48 hr
75 %
75 %
25 %
25 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2014 Dec 18 2200 UTC
0-24 hr
24-48 hr
35 %
35 %
20 %
20 %
05 %
05 %
High latitudes
0-24 hr
24-48 hr
10 %
10 %
30 %
30 %
50 %
50 %
Thursday, Dec. 18, 2014
What's up in space

Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park.

Lapland tours

RADS ON A PLANE, CONTINUED: Regular readers may remember last month's reports by Dr. Tony Phillips of radiation measurements inside commercial airplanes. During a round-trip between Reno, Nevada, and Washington DC, inside planes that flew as high as 39,000 feet, he absorbed a dose of ionizing radiation equal to approximately 3 dental x-rays.

Not every trip, however, is so "radioactive." Yesterday, he flew from Reno to San Francisco--a short hop over the Sierras to attend the American Geophysical Union meeting--and the dose was much less. Here is the radiation profile during the flight:

The data come from a pair of radiation detectors routinely flown to the stratosphere onboard Earth to Sky Calculus Space Weather Buoys. The pager-sized devices are sensitive to ionizing radiation such as X-rays and gamma-rays in the energy range 10 keV to 20 MeV. Ideally, the two detectors should register the same dose rates throughout the flight. Slight differences between the two curves are an indication of the uncertainty in the measurements.

Compared to last month's travel, there was relatively little radiation detected during this flight. From take-off to landing, the total dose was only about 3% of a dental X-ray -- about a hundred times less than before.

Why so little? For one thing, the flight was brief, less than an hour long.Moreover, it was low. The cruising altitude of the small commuter jet was only 26,000 feet. When it comes to "rads on a plane," altitude matters a lot. The source of the radiation is cosmic rays from space; the closer you are to space, the more radiation you are going to absorb. Short, low flights are best for avoiding exposure.

It is important to note that the sensors Phillips carried onboard the plane do not detect one of the most important forms of radiation: neutrons. Neutrons provide much of the biologically effective radiation dose at altitudes of interest to aviation and space tourism. To account for these uncharged particles, the doses discussed above should be doubled or tripled. To improve our estimates of the total dose rate, the students of Earth to Sky Calculus are evaluating neutron detectors for future balloon missions and plane flights. Stay tuned!

Realtime Space Weather Photo Gallery

LARGE SUNSPOTS: A pair of large sunspots has emerged in the sun's southern hemisphere, and they are almost directly facing Earth. This 48-hour movie from NASA's Solar Dynamics Observatory shows the rapid development of AR2241 and AR2242:

Both of these active regions have unstable 'beta-gamma-delta' magnetic fields that harbor energy for strong explosions. NOAA forecasters estimate a 65% chance of M-flares and a 15% chance of X-flares on Dec. 18th. Because these spots are centrally located on the solar disk, any flares today will likely be Earth-directed. Solar flare alerts: text, voice

Realtime Space Weather Photo Gallery

CHANCE OF STORMS: A coronal mass ejection (CME) is heading in the general direction of Earth, and it could deliver a glancing blow to our planet's magnetic field on Dec. 19th. Scroll past this SOHO coronagraph movie for storm probabilities:

The cloud was hurled into space on Dec. 17th by an M9-class explosion in the magnetic canopy of sunspot AR2242. Although the bulk of the cloud is traveling south of the sun-Earth line, there will be a grazing impact. NOAA forecasters estimate a 50% chance of polar geomagnetic storms when the outskirts of the CME arrive. High-latitude sky watchers should be alert for auroras on Dec. 19th. Solar flare alerts: text, voice

Realtime Space Weather Photo Gallery

EDGE OF SPACE CHRISTMAS CARDS: What do you give to the sky watcher who has everything? How about a Christmas card from the Edge of Space? For only $49.95, the students of Earth to Sky Calculus will fly your holiday greeting or favorite picture to the top of Earth's atmosphere, photograph it, and return the snapshot in time for Christmas. This holiday magic is performed using suborbital helium balloons. The group has previously flown cupcakes, shoes, US presidents, ad banners and telescopes. Contact Dr. Tony Phillips for more information.

Realtime Aurora Photo Gallery

Realtime Meteor 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. 18, 2014, the network reported 13 fireballs.
(9 sporadics, 3 December Leonis Minorids, 1 sigma 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 18, 2014 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2014 XB6
Dec 14
7.6 LD
22 m
2007 EJ
Jan 12
68.9 LD
1.1 km
1991 VE
Jan 17
40.6 LD
1.0 km
2004 BL86
Jan 26
3.1 LD
650 m
2008 CQ
Jan 31
4.8 LD
36 m
2000 EE14
Feb 27
72.5 LD
1.6 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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