You are viewing the page for Apr. 6, 2009
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 371.7 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 Apr06
24-hr: A0
2340 UT Apr06
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 06 Apr 09
The sun is blank--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 06 Apr 2009

NEW: Spotless Days
Current Stretch: 11 days
2009 total: 83 days (86%)
Since 2004: 594 days
Typical Solar Min: 485 days
explanation | more info
Updated 06 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= 0 quiet
24-hr max: Kp= 1
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 2.8 nT
Bz: 0.2 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 on or about April 9th. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Apr 06 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 06 2201 UTC
0-24 hr
24-48 hr
05 %
30 %
01 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
10 %
35 %
01 %
10 %
01 %
05 %
What's up in Space
April 6, 2009

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


VOTE FOR SOHO: The Solar and Heliospheric Observatory (SOHO) has reached the final round of NASA's Mission Madness tournament where it is competing against upstart SPB, the Super Pressure Balloon, for the title "Greatest NASA Mission." We endorse SOHO. Vote now and help propel a spaceweather favorite to the championship.

SOLAR ACTIVITY: No sunspots? No problem. Even without those planet-sized islands of explosive magnetism, the sun is putting on a nice show:

This polar crown prominence, a towering wall of plasma about 50,000 km high, was photographed yesterday by Jerome Grenier using a backyard solar telescope in Paris, France. Grenier's half-hour movie shows a phenomenon sometimes called "plasma falls." Narrow streams of plasma at the top of the prominence are constantly falling back to the bottom. Mysteriously, the streams plummet faster than ambient magnetic forces seem to allow. Nuclear engineers would like to figure out how this happens, because it also happens on a smaller scale in fusion reactors on Earth, frustrating their efforts to sustain an energy-producing reaction. Maybe prominences hold the key to the problem.

Or maybe they're just fun to watch. Readers, if you have a solar telescope, point it at the limb of the sun and enjoy the show.

more images: from James Kevin Ty of Manila, the Philippines; from N. Ferrin, J. Harmon and John Stetson of South Portland, Maine; from Eric Roel of Orion Observatory, Rancho La Compañía, México; from Greg Piepol of Rockville, Maryland; from Steve Rismiller of Milford, Ohio; from Stefano Sello of Pisa -Italy;

SULFUR DIOXIDE ON THE MOVE: When Mt. Redoubt erupted on April 4th, it shot a plume of sulfur dioxide into the lower stratosphere. That plume is on the move. The GOME-2 (Global Ozone Monitoring Experiment) sensor onboard Europe's MetOpA satellite is tracking the SO2 as it twists and curls across North America. Follow the red pixels in this 3-day (April 3-5) animation:

Click for a full-sized map with labels

Sulfur dioxide and associated aerosols have been known to produce sunsets of exceptional beauty. Examples from the 2008 eruption of Kasatochi may be found here and here. Readers in North America should keep an eye on the western twilight sky in the evenings ahead as the cloud makes its way across the continent. Stay tuned for updates.

March 2009 Aurora Gallery
[previous Marches: 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 6, 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.
©2019 All rights reserved.