You are viewing the page for Jul. 30, 2007
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 617.9 km/sec
density: 0.7 protons/cm3
explanation | more data
Updated: Today at 2245 UT
X-ray Solar Flares
6-hr max: A0
2245 UT Jul30
24-hr: A0
1250 UT Jul30
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 30 July 07
Sunspot 965 is disintegrating and almost gone; newly emerging sunspot 966 poses no threat for solar flares. Credit: SOHO/MDI
Sunspot number: 14
What is the sunspot number?
Updated 28 July 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= 4
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Updated: 2007 Jul 30 2146 UT
Interplanetary Mag. Field
Btotal: 3.0 nT
Bz: 2.3 nT north
explanation | more data
Updated: Today at 2246 UT
Coronal Holes:
Earth is inside a solar wind stream flowing from the indicated coronal hole. Credit: SOHO Extreme Ultraviolet Telescope
NOAA Forecasts
Updated at: 2007 Jul 30 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 30 2203 UTC
0-24 hr
24-48 hr
15 %
20 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
25 %
25 %
05 %
05 %
01 %
01 %
What's up in Space
July 30, 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.

SUPER-BOLIDE: On Wednesday, July 25th at approximately 10:00 UT, "a major daylight fireball tore across the skies of Slovenia, Croatia and Italy," reports veteran meteor observer Jure Atanackov of Maribor, Slovenia. "It produced two bright flashes that reached an estimated magnitude of -20 and also loud sonic booms." Magnitude -20? In plain language, the meteor was 600 times brighter than a full Moon. Eyewitnesses, please report your sightings to Jure Atanackov or colleague Javor Kac who are gathering data to learn more about this extraordinary meteor and to estimate possible landing sites.

NIGHT-SHINING CLOUDS: Noctilucent clouds (NLCs) were active over Europe last night. "It was a fantastic display," reports P-M Hedén of Vallentuna, Sweden. "I was up all night watching these wonderful, glowing clouds as they changed in structure and brightness."

Photo details: Canon Digital Rebel XT, 20mm Sigma lens

Displays like this were once reserved for northern places like Sweden, Canada and Alaska. But in recent years, mysterious NLCs have descended to lower latitudes with sightings as far south as Colorado, Utah and possibly Virginia. No matter where you live, watch the western sky one to two hours after sunset. If you see electric-blue tendrils spreading up from the horizon, you've probably spotted a noctilucent cloud: gallery.

SOLAR SPICULES: Grass is growing on the sun. Not really, but the simile is fair enough; regard this July 26th photo of the sun's limb contributed by Harald Paleske of Langendorf, Germany:

Photo details: 225/200 Unigraph, f/9.5, 1/650sec exposure

The blades are called spicules. They're jets of gas as tall as North America firing upward from the surface of the sun. Even when solar activity is "low," it is possible to find spicules in action. More than 100,000 are shooting up from the sun at any given moment. How does that compare to your lawn? There are roughly 100,000 blades of grass per square meter. Sit down cross-legged on a verdant patch of frontyard; you've just squashed almost a star's worth of spicules.

.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 30, 2007 there were 876 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.