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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 319.2 km/sec
density: 2.5 protons/cm3
explanation | more data
Updated: Today at 2246 UT
X-ray Solar Flares
6-hr max: A5
1725 UT Jul18
24-hr: B1
1355 UT Jul18
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 18 July 07
Decaying sunspot 963 poses no threat for strong solar flares. Credit: SOHO/MDI
Sunspot number: 17
What is the sunspot number?
Updated 17 July 2007
Far side of the Sun:
This holographic image reveals no large sunspots on the farside of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 1
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Updated: 2007 Jul 18 2132 UT
Interplanetary Mag. Field
Btotal: 2.7 nT
Bz: 0.8 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 or about July 20th. Credit: SOHO Extreme Ultraviolet Telescope
NOAA Forecasts
Updated at: 2007 Jul 18 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 Jul 18 2203 UTC
0-24 hr
24-48 hr
15 %
20 %
05 %
10 %
01 %
05 %
High latitudes
0-24 hr
24-48 hr
20 %
25 %
10 %
15 %
05 %
05 %
What's up in Space
July 18, 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.

PROMINENCE ALERT: "This morning I saw a huge prominence at the southeastern limb of the sun," reports Cai-Uso Wohler of Bispingen, Germany. He took this picture using his Coronado SolarMax60. "I hope this means that there is another active sunspot coming around soon," he says. Stay tuned for updates.

more images: from P-M Hedén of Vallentuna, Sweden

CORONAL HOLE: There's a big hole in the sun's atmosphere today. It's the irregular dark region in this x-ray photo taken by Japan's Hinode satellite:

Astronomers call it a coronal hole--a vast zone where the solar magnetic field opens up and allows hot gas to escape from the sun's corona. A stream of solar wind flowing from this coronal hole will reach Earth on or about July 20th. High-latitude sky watchers should be alert for auroras when it arrives. (Note: Earlier today, the estimated date of arrival was misprinted as June 20th. The correct date is July 20th.)

NLCs INVADE PENNSYLVANIA: "I was walking out to my car around 9:30 p.m. on July 15th when I looked up and saw a creepy noctilucent cloud," says Jeffrey Berkes. He dashed back inside, grabbed a camera and clicked:

This is a perfectly ordinary "nightshining" cloud. What's interesting about it is its location: "I live in West Chester, Pennsylvania," says Berkes. Normally, noctilucent clouds inhabit high latitudes--Alaska, Canada, Scandinavia. But every year in mid-to-late summer they begin to creep south. "This is my second sighting in mid-July," he says. In recent years the clouds have descended as far as Utah, Colorado and possibly even Virginia. Wherever you live, watch the western sky one to two hours after sunset. If you see electric blue tendrils spreading up from the horizon, you may have spotted a noctilucent cloud.

.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 July 18, 2007 there were 874 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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