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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 552.7 km/sec
density: 1.8 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: A0
2340 UT Apr11
24-hr: A0
0920 UT Apr11
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 11 Apr 09
The sun is blank--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 11 Apr 2009

NEW: Spotless Days
Current Stretch: 16 days
2009 total: 88 days (87%)
Since 2004: 599 days
Typical Solar Min: 485 days
explanation | more info
Updated 11 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= 3
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 3.1 nT
Bz: 1.7 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes:
Earth is inside a solar wind stream flowing from the indicated coronal hole. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Apr 11 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 11 2201 UTC
0-24 hr
24-48 hr
15 %
05 %
05 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
05 %
05 %
01 %
01 %
01 %
What's up in Space
April 11, 2009

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


CORONAL MASS EJECTION: In addition to the many prominences on display around the sun today (see below), another form of solar activity has appeared. The Solar and Heliospheric Observatory is tracking a massive coronal mass ejection (CME) billowing away from the sun's western limb: movie. The slow-moving cloud will not hit Earth.

SOLAR ACTIVITY: "Solar minimum? No problem," reports Marco Vidovic of Stojnci, Slovenia. "Lately, every time I point my telescope at the edge of the sun, I see plenty of activity." He took this picture yesterday:

Vidovic uses a telescope equipped with an H-alpha filter tuned to the red glow of solar hydrogen. H-alpha filters are ideal for catching prominences--towering plumes of hydrogen held aloft by the sun's magnetic field. Because prominences are not rooted in sunspots, they do not vanish when the sunspot count plunges to zero.

Far from zero, the prominence count today is seven. Readers, if you have an H-alpha telescope, take a look at the solar activity that won't go away.

more images: from Ali and John Stetson of South Portland, Maine; from Cai-Uso Wohler of Bispingen, Germany; from Matthias Juergens of Gnevsdorf, Germany; from Stephen Ames of Hodgenville, Kentucky

COMET Yi-SWAN: It's up all night long. Northern circumpolar Comet Yi-SWAN is gliding through the constellation Cassiopeia where it can be seen at almost any hour of the night through amateur telescopes. Working at his backyard observatory in Ellisville, Missouri, Gregg Ruppel took this picture on April 9th:

At the moment, the green, fuzzy comet is about as bright as an 8th-magnitude star--too dim for the naked eye. If predictions are correct, it will remain a telescopic comet, brightening only a little as it approaches the sun for a 190 million kilometer not-so-close encounter on May 8th. Astronomers will get a better look at the comet in the evenings ahead as the bright light of the full Moon fades.

Comet Yi-SWAN was co-discovered by amateur astronomers Dae-am Yi in Korea and Rob Matson in the USA. Yi photographed the comet himself using a Canon 5D and a 90 mm lens. Matson noticed it in images taken by the Solar and Heliospheric Observatory's SWAN sensor. Because of naming traditions (which should probably be modified) the comet bears SWAN's name, not Matson's.

This appears to be Comet Yi-SWAN's first visit to the inner solar system. A fresh comet exposed to intense sunlight for the first time can behave in unexpected ways. Will it grow a tail, fragment, brighten ... ? Stay tuned for updates.

related links: 3D orbit, ephemeris

Explore the Sunspot Cycle

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

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 11, 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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