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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 445.8 km/sec
density: 5.7 protons/cm3
explanation | more data
Updated: Today at 2246 UT
X-ray Solar Flares
6-hr max: A0
2245 UT Aug15
24-hr: A0
2245 UT Aug15
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 15 Aug 07
Sunspot 966 has faded away, leaving the sun blank. Credit: SOHO/MDI
Sunspot number: 14
What is the sunspot number?
Updated 14 Aug 2007
Far side of the Sun:
This holographic image reveals one possible sunspot on the far side of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 3
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Updated: 2007 Aug 15 2117 UT
Interplanetary Mag. Field
Btotal: 3.6 nT
Bz: 0.9 nT north
explanation | more data
Updated: Today at 2246 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on Aug. 15th or 16th. Credit: SOHO Extreme Ultraviolet Telescope
NOAA Forecasts
Updated at: 2007 Aug 15 2203 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: 2007 Aug 15 2203 UTC
0-24 hr
24-48 hr
25 %
20 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
30 %
25 %
15 %
05 %
05 %
01 %
What's up in Space
August 15, 2007
Where's Saturn? Is that a UFO--or the ISS? What's the name of that star? Get the answers from mySKY--a fun new astronomy helper from Meade.

RE-ENTRY ALERT: A Delta 2 rocket body used to laucnh the COSMOS 1 satellite in June 2007 should re-enter Earth's atmosphere within the next couple of hours. Ground tracks shown here trace the possible reentry corridors; uncertainties in the rocket's decay rate make it impossible to say precisely where the fireball will appear. Sightings, if any, will be reported on

SOLAR PROMINENCE: "There's a beautiful prominence on the sun today," reports Guenter Kleinschuster who took this picture from his backyard in Feldbach, Austria. The arcing cloud of hot hydrogen towers almost three Earth diameters over the sun's northeastern limb. Readers, if you have a solar telescope, take a look!

more images: from Jack Newton of Osoyoos, British Columbia; from Cai-Uso Wohler of Bispingen, Germany; from Pavol Rapavy of Rimavska Sobota, Slovakia; from David Storey of Dougla, Isle of Man, UK;

NOCTILUCENT WAVES: On August 10th, scientists from SRI International at NSF's research facility in Sondrestrom, Greenland, shot a laser into a bank of noctilucent clouds (NLCs) passing overhead. "This is the best way to probe these mysterious clouds from the ground," says lidar team member Jeff Thayer of the University of Colorado. Their experiment revealed not only the clouds' height and thickness (80+ km high and ~1 km thick), but also some strange undulating waves:

"We believe the waves are caused by atmospheric gravity waves, or buoyancy waves, generated in the lower atmosphere and propagating vertically to the edge of space where noctilucent clouds are located," explains Thayer. When the waves reach the upper limit of Earth's atmosphere, "they can become unstable and crash – much like waves approaching and crashing on a beach."

"We have been 'pinging' NLCs from Greenland for more than 12 years, but every time it is exciting and novel," he says. During this particular observation, NASA's AIM satellite was flying overhead and observing the same waves from above. "The combined analysis will be extremely informative and exciting."

2007 Noctilucent Cloud Gallery
[Night-Sky Cameras] ["Noctilucent Cloud"--the song]

AURORA WATCH: On August 11th, a solar wind stream brushed against Earth's magnetic field. It was a gentle impact, but enough to produce this fantastic display:

Brian Whittaker took the picture from an airplane 35,000 feet above the USA-Canada border near the Lake of the Woods. "This great display of green auroras lasted several hours," he says. "It was particularly beautiful in the northern USA where dramatic thunderstorms actively illuminated the horizon at an alarming frequency only to be supplemented by the occasional Perseid."

Another solar wind stream is due to arrive today or tomorrow. High-latitude sky watchers, be alert for auroras.

2007 Perseid Meteor Gallery
Updated Aug. 14, 2007

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 15, 2007 there were 878 potentially hazardous asteroids.
July 2007 Earth-asteroid encounters:
Miss Distance
2007 FV42
July 2
53 LD
1.2 km
2007 MB4
July 4
7.6 LD
130 m
2007 DT103
July 29
9.3 LD
550 m
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 Environment Center
  The official U.S. government bureau for real-time monitoring of solar and geophysical events, research in solar-terrestrial physics, and forecasting solar and geophysical disturbances.
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.
Daily Sunspot Summaries
  From the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
  more links...
©2007, -- This site is penned daily by Dr. Tony Phillips.
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