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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 384.2 km/sec
density: 6.6 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: C1
2335 UT Aug17
24-hr: C1
2335 UT Aug17
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 17 Aug 10
Active sunspot complex 1093-1099 has just rotated over the sun's western limb.
Resolutions: 4096, 1024, 512
Sunspot number: 39
What is the sunspot number?
Updated 16 Aug 2010

Spotless Days
Current Stretch: 0 days
2010 total: 35 days (15%)
2009 total: 260 days (71%)
Since 2004: 803 days
Typical Solar Min: 486 days
explanation | more info
Updated 16 Aug 2010

The Radio Sun
10.7 cm flux: 85 sfu
explanation | more data
Updated 16 Aug2010

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: 4.3 nT
Bz: 2.8 nT south
explanation | more data
Updated: Today at 1437 UT
Coronal Holes:
There are no large coronal holes on the Earth-facing side of the sun. Credit: SDO/AIA
NOAA Forecasts
Updated at: 2010 Aug 17 2201 UTC
0-24 hr
24-48 hr
01 %
01 %
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: 2010 Aug 17 2201 UTC
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
What's up in Space
August 17, 2010

iPHONE VS ANDROID! Actually, it doesn't matter which phone you carry. Our cool, new app turns both smartphones into field-tested satellite trackers. Learn more.


SPACECRAFT APPROACHES VENUS: A Japanese spacecraft named "Akatsuki" is approaching Venus on a mission that planetary scientists say could end up teaching us a great deal about Earth. Get the full story from Science@NASA.

GREEN SNOW: Tonight's weather forecast in Antarctica calls for a 35% chance of green snow. Yes, green. It turns that color during geomagnetic storms, as shown in this August 1st photo from Nick Roden of Australia's Davis Station on the Antarctic coast:

"We've had some fantastic aurora displays lately--bright enough to reflect from the snow," says Roden. In addition to the green auroras, there is also a green laser lancing up from the research station in the background. "That's our LIDAR, which we use to study the upper atmosphere."

A new episode of green may be in the offing. A coronal mass ejection (CME) is expected to deliver a glancing blow to Earth's magnetic field on Aug. 17th or 18th, and NOAA forecasters estimate a 35% chance of polar geomagnetic activity when the cloud arrives.

August 2010 Northern Lights Gallery
[previous Augusts: 2009, 2008, 2007, 2006, 2005, 2004, 2003]

BIG PERSEID: The vast majority of meteoroids that hit Earth's atmosphere during last week's Perseid meteor shower were mere specks of comet dust, massing no more than a fraction of a gram. This one was a big exception:

"The University of Western Ontario network of all-sky cameras captured this Perseid on August 13th," says Bill Cooke of NASA's Meteoroid Environment Office. "It weighed in at about 1.5 kilograms." The 14-cm comet chunk hit Earth's atmosphere at 140,000 mph, creating a flash of light about as bright as a quarter Moon. "Now that was a Perseid!"

"There is another somewhat dimmer Perseid fireball just below it," points out Cooke. "It massed only 2 grams--but that was still enough to make a flash as bright as Venus. In this one image," he marvels, "we see two meteoroids with a mass ratio of 750:1."

More Perseids, big and small, may be found flitting through the gallery.

2010 Perseid Photo Gallery
[meteor radar] [Perseid fireball cam]


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 17, 2010 there were 1144 potentially hazardous asteroids.
Upcoming Earth-asteroid encounters:
Miss Distance
2002 CY46
Sep 2
63.8 LD
2.4 km
2010 LY63
Sep 7
56 LD
1.2 km
2009 SH2
Sep 30
7.1 LD
45 m
1998 UO1
Oct 1
32.1 LD
2.1 km
2005 GE59
Oct 1
77 LD
1.1 km
2001 WN5
Oct 10
41.8 LD
1.0 km
1999 VO6
Oct 14
34.3 LD
1.8 km
1998 TU3
Oct 17
69.1 LD
5.3 km
1998 MQ
Oct 23
77.7 LD
1.9 km
2007 RU17
Oct 29
40.6 LD
1.0 km
2003 UV11
Oct 30
5 LD
595 m
3838 Epona
Nov 7
76.8 LD
3.4 km
2005 QY151
Nov 16
77.7 LD
1.3 km
2008 KT
Nov 23
5.6 LD
10 m
2002 EZ16
Nov 30
73.9 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 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 and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
Science Central
  more links...
©2008, -- This site is penned daily by Dr. Tony Phillips.













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