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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 399.5 km/sec
density: 1.0 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: A0
2340 UT May28
24-hr: A0
2340 UT May28
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 28 May 09
The sun is blank--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 27 May 2009

Spotless Days
Current Stretch: 4 days
2009 total: 120 days (81%)
Since 2004: 631 days
Typical Solar Min: 485 days
explanation | more info
Updated 27 May 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
Interplanetary Mag. Field
Btotal: 0.9 nT
Bz: 0.8 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth sometime between June 1st and 3rd. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 May 28 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 May 28 2201 UTC
0-24 hr
24-48 hr
15 %
10 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
01 %
01 %
01 %
01 %
What's up in Space
May 28, 2009

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


CAN PEOPLE GO TO MARS? A new study shows that an 18-month mission to Mars could expose astronauts to more space radiation than NASA shielding technology can handle. Long-term missions to the Moon could be problematic, too. Get the full story from Science@NASA.

EIFFEL LIGHTNING BOLT: Believe it or not, bolts of lightning are shooting out of the Eiffel Tower. Photographer Hakim Atek caught it happening on May 25th:

Photo Details: Nikon D80 + Nikkor 18-135mm, ISO 100, f/8, 30s, +2.0ev

"I saw some lightning out the window of my home in Paris," says Atek. "So I set up a tripod and pointed my camera (a Nikon D80) at the Eiffel Tower. I never expected to get such an amazing picture."

But did the Tower really make its own lightning? The surprising answer is "yes."

"The upward branching in this photo shows that the Eiffel Tower actually initiated the discharge," says lightning researcher Richard Blakeslee of the NASA Marshall Space Flight Center. "In other words, instead of starting in the cloud and coming to ground, this flash started when the tower 'launched' a leader that propagated upward toward the cloud (which still served as the source of the electric field needed to get the process going). As the leader ascended, it branched out. Eventually one of the branches reached a region of sufficient charge to 'short out the cloud' and produce the return stroke pictured above."

According to Martin Uman's classic text The Lightning Discharge, upward-initiated discharges are "relatively rare," accounting for less than 1% of all lightning, "and generally occur from mountain tops and tall man-made structures." K. Berger, who studied lightning from a mountaintop location 30+ years ago, was one of the first to describe the phenomenon. Reference: Blizstrom-parameter van aufwarsblizen, Bull. Schweiz. Elektrotech., 69, 353-360, 1978.

more images: from Jens Hackmann of Wuerzburg, Germany; from David Hough of Warner's Bay, NSW, Australia; from Joe Cascio of Buffalo, New York;

JUPITER'S MOON SHOW: Every six years, Earth spends a number of months passing through the orbital plane of Jupiter's moons. During the passage, amateur astronomers get to see a rare display of "mutual occultations." Jupiter's moons eclipse one another in plain view of backyard telescopes.

On May 25th, Mike Salway of Central Coast, Australia, watched Ganymede pass in front of Io. Click on the still-frame to launch a 0.25 MB movie:

Images like these are unprecedented. Although Jupiter's moons put on the same kind of show in 2002-2003, no one recorded such clear pictures. "Imaging techniques and equipment have improved immensely over the past 6 years," notes Salway. "So this is the first year where amateurs are recording these events and producing detailed, high-resolution images of the phenomena."

If you missed the Ganymede-Io eclipse, don't worry. There are plenty more to come. Mutual occultations of Jupiter's moons will continue from now until nearly the end of the year. As part of the International Year of Astronomy, professional astronomers are organizing a worldwide observing campaign to record as many of these events as possible. Click here for details.

more images: from Efrain Morales Rivera of Aguadilla, Puerto Rico; from Paul Maxson of Surprise, Arizona

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 May 28, 2009 there were 1060 potentially hazardous asteroids.
May 2009 Earth-asteroid encounters:
Miss Distance
2009 JA
May 4
7.5 LD
37 m
2006 FG3
May 6
60.7 LD
1.1 km
2001 SG286
May 17
11.5 LD
280 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 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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