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You entered an invalid date. This is yesterday's edition. -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids Internet Shopping Sites high quality binoculars excellent weather stations all-metal reflector telescopes rotatable microscopes
Solar wind
speed: 339.3 km/sec
density: 6.3 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: C7
1904 UT Aug21
24-hr: M3
1331 UT Aug21
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 21 Aug 14
Not one of these sunspots has the type of complex magnetic field that harbors energy for strong flares. Solar activity is low. Credit: SDO/HMI
Sunspot number: 89
What is the sunspot number?
Updated 21 Aug 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%)

21 Aug 2014

The Radio Sun
10.7 cm flux: 118 sfu
explanation | more data
Updated 21 Aug 2014

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 4.8 nT
Bz: 0.8 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 21 Aug 14
There are no large coronal holes on the Earthside of the sun. 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: 08-21-2014 12:55:08
NOAA Forecasts
Updated at: 2014 Aug 21 2200 UTC
0-24 hr
24-48 hr
25 %
25 %
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: 2014 Aug 21 2200 UTC
0-24 hr
24-48 hr
20 %
05 %
05 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
15 %
10 %
15 %
05 %
Thursday, Aug. 21, 2014
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

MYSTERY IN THE OZONE LAYER: More than 27 years after the Montreal Protocol regulated chemicals that destroy ozone, a damaging compound named carbon tetrachloride (CCl4) is still surprisingly abundant in the ozone layer. "We are not supposed to be seeing this at all," says NASA atmospheric scientist Qing Liang. Countries around the world report zero emissions of CCl4, yet the amount actually in the ozone layer corresponds to 39 kilotons per year. Where is the compound coming from? Some of the possibilities are discussed in a NASA press release.

WEAK IMPACT? MAGNIFICENT AURORAS: Visually, the CME that struck Earth's magnetic field on August 19th was dim and unimpressive. The auroras it produced were magnificent. "For the first time in my life, I saw the Northern Lights," says Tadas JanuĊĦonis who sends this photo from Vabalninkas, Lithuania:

"It is a very rare phenomenon here in Lithuania," he says, "but the August 19th impact was strong enough to [produce] them."

Actually, the impact was weak. A CME like this one hits with a mechanical pressure of no more than 1 or 2 nanoPascals. That's 1 or 2 billionths of a Pascal - softer than a baby's breath. The reason it was so effective had more to do with its inner magnetic structure. This CME contained a region of south-pointing magnetism that partially canceled Earth's north-pointing magnetic field, opening a crack in the magnetosphere. Solar wind poured and fueled the display.

The most famous photo of the storm, so far, was taken by astronaut Reid Wiseman onboard the International Space Station. "Never in my wildest dreams did I imagine this, " he tweeted. "Unbelievable." Yet many more photos prove that it really did happen! Aurora alerts: text, voice

Realtime Aurora Photo Gallery

MORNING SHOW CONTINUES: Light pollution? No problem. The morning conjunction of Venus and Jupiter is bright enough to see through the worst urban glare. Jeff Dai sends this picture from metropolitan Chongqing, China:

"I woke up at 5 AM to enjoy this celestial dawn above the cityscape," says Dai. "It was gorgeous."

Dai took the picture on August 20th, two days after Venus and Jupiter were barely 0.2o apart. Many observers have stopped looking now that the planets are separating, but as Dai's photo shows, they are still a beautiful pair. So set your alarm for dawn: the morning show continues. A date of special interest is August 23rd when the crescent Moon joins the planets to form a must-see celestial triangle. A video from NASA previews the meeting.

Realtime Conjunction Photo Gallery

Realtime Comet Photo Gallery

Realtime Meteor Photo Gallery

Realtime NLC 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 Aug. 21, 2014, the network reported 32 fireballs.
(30 sporadics, 2 kappa Cygnids)

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 August 21, 2014 there were 1495 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2001 RZ11
Aug 17
34.2 LD
2.2 km
2013 WT67
Aug 17
16.1 LD
1.1 km
2013 RZ53
Sep 9
1.9 LD
3 m
2002 CE26
Sep 9
47.9 LD
1.8 km
2009 RR
Sep 16
2 LD
34 m
2006 GQ2
Sep 19
65.9 LD
1.1 km
2009 FG19
Sep 26
34.6 LD
1.1 km
2014 NE52
Sep 30
61.2 LD
1.1 km
2001 EA16
Oct 7
35.5 LD
1.9 km
2011 TB4
Oct 9
5.8 LD
34 m
2003 UC20
Oct 31
52.4 LD
1.0 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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