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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 304.7 km/sec
density: 2.2 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: A0
2340 UT Apr15
24-hr: A0
2340 UT Apr15
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 15 Apr 09
The sun is blank--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 15 Apr 2009

NEW: Spotless Days
Current Stretch: 20 days
2009 total: 92 days (88%)
Since 2004: 603 days
Typical Solar Min: 485 days
explanation | more info
Updated 15 Apr 2009

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= 1 quiet
24-hr max: Kp= 2
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 4.0 nT
Bz: 2.6 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole could reach Earth on April 16th or 17th. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Apr 15 2201 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: 2009 Apr 15 2201 UTC
0-24 hr
24-48 hr
05 %
15 %
01 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
10 %
20 %
01 %
05 %
01 %
01 %
What's up in Space
April 15, 2009

AURORA ALERT: Did you sleep through the Northern Lights? Next time get a wake-up call: Spaceweather PHONE.


FEROCIOUS CROISSANTS: For the first time, NASA spacecraft have traced the 3D shape of solar storms known as coronal mass ejections (CMEs). It turns out the most ferocious CMEs resemble something from a French bakery. Get the full story from Science@NASA.

SLOW-MOTION EXPLOSIONS: How deep is solar minimum? Consider this: The most powerful solar explosions are now moving in slow motion. "Lately, coronal mass ejections (CMEs) have become very slow, so slow that they have to be dragged away from the sun by the solar wind," says researcher Angelos Vourlidas of the Naval Research Lab. Here is an example from April 11th:

Each second in the SOHO animation corresponds to an hour or more of real time. "The speed of the CME was only 240 km/s," says Vourlidas. "The solar wind speed is about 300 km/s, so the CME is actually being dragged."

Vourlidas has examined thousands of CMEs recorded by SOHO over the past 13 years, and he's rarely seen such plodding explosions. In active times, CMEs can blast away from the sun faster than 1000 km/s. Even during the solar minimum of 1996, CMEs often revved up to 500 or 600 km/s. "Almost all the CMEs we've seen since the end of April 2008, however, are very slow, less than 300 km/s."

Is this just another way of saying "the sun is very quiet?" Or do slow-motion CMEs represent a new and interesting phenomena? The jury is still out. One thing is clear: solar minimum is more interesting than we thought.

FLY SPECK: Before you continue reading, flick away any insects that might be crawling across your screen. Done? The one you couldn't remove is the International Space Station (ISS):

Raymond Dubois of Ottawa, Canada, photographed the station's winged silhouette zipping in front of the sun on April 12th. "This was my fourth try at photographing a solar transit of the ISS, and I finally succeeded," he says. "I mounted my camera (a Nikon D300) on a Baader solar-filtered telescope and let it rip at 8 frames per second. The photo shown above is exactly what I captured--no corrections or manipulations were done."

The station's insectoid appearance is a result of recent construction. Last month, astronauts added an enormous new pair of solar arrays to the station's starboard side. The light-collecting wings are producing enough power to double the size of the crew from three to six and also to double the number of science experiments underway in the station's laboratories.

The station's wings look great in silhouette, but they look even better shining among the stars at night. Check the Simple Satellite Tracker for viewing times.

UPDATED: April 2009 Aurora Gallery
[previous Aprils: 2008, 2007, 2006, 2005, 2004, 2003, 2002]

Explore the Sunspot Cycle

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 April 15, 2009 there were 1050 potentially hazardous asteroids.
April 2009 Earth-asteroid encounters:
Miss Distance
2009 FU30
Apr. 2
8.8 LD
44 m
2004 VC
Apr. 3
51.3 LD
785 m
2002 EB3
Apr. 10
41.3 LD
1.3 km
2003 SG170
Apr. 19
57.7 LD
1.2 km
2009 FJ30
Apr. 24
9.7 LD
130 m
2001 VG5
Apr. 26
58.5 LD
2.1 km
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 Weather Prediction Center
  The official U.S. government space weather bureau
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.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
Science Central
  more links...
©2008, -- This site is penned daily by Dr. Tony Phillips.
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