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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
SPACE WEATHER
Current conditions
Solar wind
speed: 487.2 km/sec
density: 2.2 protons/cm3
explanation | more data
Updated: Today at 2246 UT
X-ray Solar Flares
6-hr max: A0
2245 UT Aug11
24-hr: A0
0325 UT Aug11
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 11 Aug 07
Tiny sunspot 966 poses no threat for strong solar flares. Credit: SOHO/MDI
Sunspot number: 14
What is the sunspot number?
Updated 10 Aug 2007
Far side of the Sun:
This holographic image reveals no large sunspots on the far side of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3
quiet
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Updated: 2007 Aug 11 2130 UT
Interplanetary Mag. Field
Btotal: 3.3 nT
Bz: 0.4 nT north
explanation | more data
Updated: Today at 2247 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on or about Aug. 15th. Credit: SOHO Extreme Ultraviolet Telescope
SPACE WEATHER
NOAA Forecasts
Updated at: 2007 Aug 11 2203 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
01 %
01 %
CLASS X
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 11 2203 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
10 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
What's up in Space
August 11, 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.

SPACE STATION FLYBYS: Space shuttle Endeavour is docked to the International Space Station, and the pair are orbiting over Europe this weekend, making many bright evening passes. Last night in Gencsapáti, Hungary, Gábor Szendrői saw the spaceships through his 14-inch backyard telescope: image. Europeans, get your flyby predictions from Heavens Above.

PERSEID FIREBALLS: The Perseid meteor shower is underway. Don't panic, the peak doesn't occur until August 12th and 13th, but already 10+ shooting stars per hour may be seen during the dark hours before dawn. On August 9th, Thomas O'Brien caught this green fireball streaking over the mountains near Aspen, Colorado:

"I saw lots of green and yellow meteors," he says. Why the colors? Yellow can be a sign of sodium-rich meteoroids; hot sodium vapors glow yellow like a sodium discharge lamp. Green may be due to oxygen--not in the meteoroid but in Earth's atmosphere. When a meteoroid rips through the atmosphere, air in its path becomes so hot that oxygen molecules briefly lose one of their electrons. They recombine (e- + O2+) very rapidly, emitting green photons as a side-effect. A similar process is responsible for the green colors of many auroras.

Sky watchers, be alert for colorful Perseids in the nights ahead.

2007 Perseid Meteor Gallery
[observing tips] [sky map]

THE VIEW FROM ABOVE: Astronauts onboard the ISS and shuttle Endeavour will watch the Perseid meteor shower from above. What will that be like? In 2001, space shuttle Discovery (STS-105) orbited Earth during a Perseid shower, and the crew recorded this NASA video of a Perseid hitting Earth's atmosphere. Astronauts onboard the ISS have also enjoyed Leonid meteor storms from orbit: full story.

METEOR RADAR: The University of Western Ontario operates a 17-38 MHz meteor orbit radar. Pictured below is their sky map of activity on August 10th:

The bright, circled blobs denote meteor radiants--i.e., regions of sky where many meteors are emerging. On August 10th, the radiant of the Southern Delta Aquarid meteor shower (a relatively minor shower caused by an unknown comet) was slightly more active than the Perseids. This will change in the nights ahead as the Perseids intensify. Stay tuned for updates.

Notes: The horizontal and vertical axes of the radar map are standard astronomical coordinates, right ascension (RA) and declination (dec). The many random-looking blobs in the background of the radar map are caused by random or "sporadic" meteors not associated with any specific comet.


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

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 11, 2007 there were 875 potentially hazardous asteroids.
July 2007 Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2007 FV42
July 2
53 LD
15
1.2 km
2007 MB4
July 4
7.6 LD
16
130 m
2007 DT103
July 29
9.3 LD
15
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, SpaceWeather.com -- This site is penned daily by Dr. Tony Phillips.
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