You are viewing the page for Apr. 7, 2009
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 362.5 km/sec
density: 0.8 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: A0
2340 UT Apr07
24-hr: A0
2340 UT Apr07
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 07 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: 12 days
2009 total: 84 days (87%)
Since 2004: 595 days
Typical Solar Min: 485 days
explanation | more info
Updated 07 Apr 2009

Far side of the Sun:
This holographic image seems to show a sunspot on the far side of the sun, but the detection may be spurious. NASA's STEREO-B spacecraft, which has a direct view of the area, does not confirm an active region. 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: 1.4 nT
Bz: 0.4 nT north
explanation | more data
Updated: Today at 2346 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on April 9th or 10th. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Apr 07 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 07 2201 UTC
0-24 hr
24-48 hr
30 %
35 %
05 %
10 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
35 %
35 %
10 %
15 %
05 %
05 %
What's up in Space
April 7, 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.

SULFUR DIOXIDE LOOP: A loop of sulfur dioxide gas approximately 600 miles in diameter is swirling off the coast of California. It came from Alaska where Mt. Redoubt unleashed its biggest eruption yet on April 4th. Click on the image to launch a 4-day animation of the volcano's SO2 emissions:

Data source: The GOME-2 sensor onboard Europe's MetOp-A satellite

The April 4th eruption produced a long plume of stratospheric SO2 which has since split. Half is drifting across the northern reaches of Canada; the other half is having a close encounter with the Pacific coast of North America.

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 the path of Redoubt's clouds should be alert for rare colors and rays in the evening sky.

DAYLIGHT TRANSIT: On April 5th, John Stetson of Freeport, Maine, was watching the Moon in broad daylight when a bright light flitted across the Sea of Serenity. It was the International Space Station:

"The ISS passed in front of the Moon at 5:41 p.m.," says Stetson. "At the time, the Moon was 21 degrees above the eastern horizon while the sun was 21 degrees above the western horizon. This was a bright daylight transit."

"A local bird of prey was transiting at the same time, eclipsing a hawk-shaped portion of Mare Imbrium, the Sea of Rains," he notes.

Stetson's photo adds the space station to a short list of things you can see in the daylight sky: The Sun, Moon, Venus, clouds, birds, and now the ISS.

more images: from Pawel Warchal of Zalas, Poland

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 7, 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.