You are viewing the page for Aug. 18, 2007
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 371.0 km/sec
density: 6.8 protons/cm3
explanation | more data
Updated: Today at 2255 UT
X-ray Solar Flares
6-hr max: A9
2235 UT Aug18
24-hr: B3
1135 UT Aug18
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 18 Aug 07
The sun is blank today--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 17 Aug 2007
Far side of the Sun:
This holographic image reveals no sunspots 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 18 2052 UT
Interplanetary Mag. Field
Btotal: 4.9 nT
Bz: 3.4 nT north
explanation | more data
Updated: Today at 2256 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on or about Aug. 19th. Credit: SOHO Extreme Ultraviolet Telescope
NOAA Forecasts
Updated at: 2007 Aug 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 Aug 18 2203 UTC
0-24 hr
24-48 hr
20 %
15 %
05 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
25 %
20 %
05 %
05 %
01 %
01 %
What's up in Space
August 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.

SPACE SHUTTLE UPDATE: The threat of Hurricane Dean closing mission control in Houston has prompted NASA to recall Endeavour to Earth one day early. Undocking will occur on Sunday and landing on Tuesday: more. North Americans should be alert for double-spaceship flybys after dark on Aug. 19th and 20th.

SOLAR ACTIVITY: Several large and beautiful prominences have popped up on the sun today. "What a nice display," says Mark Hanson of the Grenier Solar Observatory in Wisconsin. "This is one of the more active times on the sun's limb over the last 6 months." If you have a solar telescope, take a look!

more images: from Michael Borman of Evansville, Indiana; from Cai-Uso Wohler of Bispingen, Germany; from Monty Leventhal of Sydney, Australia; from J. Fairfull and J. Stetson of South Portland, Maine; from P-M Hedén of Vallentuna, Sweden; from Pavol Rapavy of Rimavska Sobota, Slovakia; from Fabrice Noel of Saclay, France; from Franck Charlier of Marines, Val d'Oise - France

DON'T TRY THIS AT HOME: Today, Venus is only 8° from the sun, which means pointing a telescope at Venus is a risky thing to do. But, oh the rewards! Denis Joye of Boulogne, France, used a webcam and his Meade LX200 "goto" telescope to take this picture today in broad daylight:

Venus' nightside is turned almost entirely toward Earth; that's why it appears in crescent form. There's no prettier sight in the heavens.

But it is perilous. "Danger is encountered when Venus is observed near the sun with an LX200," says Joye. "Between 3° and 13°, a paper ignites when placed in front of the telescope's tube. At 2°, the annular space between the secondary mirror and plastic cap is melting. Never try it when the angle is lower than 2°!"

more images: from Rich Nugent of Framingham, Massachusetts; from Elias Chasiotis of Markopoulo, Greece; from Mark Wloch of Southgate, Michigan; from Pete Lawrence of Selsey, UK; from Dave Eagle of Higham Ferrers, England; from Mauro Zorzenon and Lucio Furlanetto on Matajur Mountain, Italy;

SPACESHIP SIGHTINGS: The International Space Station (ISS) is under construction, and with each new addition the sprawling complex becomes easier to see from the ground. To the naked eye, it looks like a super-bright star gliding slowly across the night sky; a backyard telescope reveals a wonderfully detailed spaceship:

Click on the image for labels

German astronomer Stefan Seip snapped this picture on August 16th using a Canon 1Ds digital camera and a 10-inch Maksutov-Cassegrain telescope. "I moved the telescope manually while looking through the finder scope to track the ISS," he explains. "This is a single 1/500 sec. exposure at ISO 1000."

A note of scale: The station's copper-colored solar arrays span 256 feet from tip to tip, almost as wide as a football field, and the entire complex fills the eyepiece of a backyard telescope about the same as Jupiter or the rings of Saturn. Sky watchers, be alert for flybys!

more images and video: from Tom Gwilym of Renton, Washington; from Ralf Vandebergh of the Netherlands; from Hanno Falk of Flensburg, Germany (cross your eyes!); from Dirk Ewers of Hofgeismar, Germany; from Mario Weigand of Offenbach, Germany; from Alberto Zampieron of Italy.

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 18, 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.
©2019 All rights reserved.