You are viewing the page for Apr. 8, 2011
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 386.8 km/sec
density: 0.2 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B7
1824 UT Apr08
24-hr: B7
1824 UT Apr08
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 08 Apr 11
None of the spots on the sun's visible disk poses a threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 73
What is the sunspot number?
Updated 07 Apr 2011

Spotless Days
Current Stretch: 0 days
2011 total: 1 day (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days

Updated 07 Apr 2011

The Radio Sun
10.7 cm flux: 112 sfu
explanation | more data
Updated 07 Apr 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 6.2 nT
Bz: 5.6 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 08 Apr 11
A solar wind stream flowing from the indicated coronal hole could brush against Earth's magnetic field on April 10th or 11th. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Apr 08 2200 UTC
0-24 hr
24-48 hr
05 %
05 %
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: 2011 Apr 08 2200 UTC
0-24 hr
24-48 hr
15 %
35 %
01 %
10 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
40 %
05 %
15 %
01 %
05 %
Friday, Apr. 8, 2011
What's up in space

Are we alone? Your iPhone has the answer. Download the all-new Drake Equation app to calculate the population of the Milky Way.

DrakeEQ for iPhone and iPad

FARSIDE ACTIVITY: NASA's STEREO probes are monitoring strong activity on the far side of the sun. A spectacular CME erupted during the early hours of April 8th apparently from old sunspot AR1176. This is the second day in a row that the active region has hurled massive clouds into space. Movies: April 7, April 8.

TENNESSEE FIREBALL: Space rocks have landed in Tennessee. That's the conclusion of researchers who recorded a brilliant fireball streaking over the Smoky Mountain state on Wednesday evening. Bill Cooke of NASA's Meteoroid Environment Office reports: "On April 6th at 8:21:57 CDT, NASA all-sky meteor cameras detected a very bright fireball moving north across the state of Tennessee. First detected 52 miles above the Arnold Air Force base near Tullahoma, the meteor was brighter than crescent Moon and was approximately 2 feet in diameter, with a weight of 200 lbs. It was last recorded 30 miles above the town of Woodbury, Tennessee, moving at a speed of approximately 9 miles per second (32,400 mph)."

Cooke continues: "The NASA Meteoroid Environment Office has reasonable confidence that some fraction of this meteor survived to the ground as one or more meteorites. Calculations are underway to determine the general impact location, which may lie close to the Kentucky border. Eyewitnesses to the fireball are encouraged to make a report to the American Meteor Society or to the Meteoroid Environment Office."

The smart cameras of Cooke's fireball network are able to calculate the orbits of incoming fireballs and backtrack their trajectories into the solar system. "The orbit of this interloper indicates that it came from the Asteroid Belt, with an aphelion well beyond the orbit of Mars."

STEADY SKIES OVER JAPAN: Only a few hours before a new and powerful earthquake shook Japan on April 7th, amateur astronomer Mitsuo Muraoka of Hatoyama, Saitama, photographed a conjunction of the crescent Moon and the Pleiades:

"It was a beautiful sight," says Muraoka. "Only a little while later, however, [I might have had trouble steadying my camera]."

According to the Japan Meteorological Agency, a 7.4 magnitude aftershock of the March 11th super-quake struck offshore at 11:30 pm Japan time. The latest quake did do some damage to the island nation, but no tsunami is forthcoming. Astronomers there can return their attention to the sky, which remained steady throughout.

more moonshots: from Stephan Heinsius of Dreieich, Germany; from Tamás Ábrahám of Zsámbék, Hungary; from Stefano De Rosa of Turin, Italy; from Tavi Greiner of Shallotte, NC; from Doug Zubenel at the St. Philippine Duchesne Memorial Park, Linn County, Kansas; from Rafael Schmall of Kaposfo, Somogy, Hungary; from Alfredo Garcia Jr of Lomita, CA; from Monika Landy-Gyebnar of Veszprem, Hungary;

April 2011 Aurora Gallery
[previous Aprils: 2010, 2009, 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 8, 2011 there were 1214 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 GW9
Apr 6
0.5 LD
10 m
2011 GP28
Apr 6
0.2 LD
6 m
2011 FT29
Apr 7
6.3 LD
38 m
2011 GZ2
Apr 8
2.7 LD
26 m
2011 FT53
Apr 9
6 LD
34 m
2011 GE
Apr 13
4.8 LD
26 m
2002 DB4
Apr 15
62.5 LD
2.2 km
2011 GJ3
Apr 27
7.7 LD
24 m
2008 UC202
Apr 27
8.9 LD
10 m
2009 UK20
May 2
8.6 LD
23 m
2008 FU6
May 5
75.5 LD
1.2 km
2003 YT1
May 5
65.3 LD
2.5 km
2002 JC
Jun 1
57.5 LD
1.6 km
2009 BD
Jun 2
0.9 LD
9 m
2002 JB9
Jun 11
71.5 LD
3.2 km
2001 VH75
Jun 12
42.2 LD
1.1 km
2004 LO2
Jun 15
9.9 LD
48 m
2001 QP181
Jul 2
35.1 LD
1.0 km
2003 YS117
Jul 14
73.9 LD
1.0 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 web 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 Dynamics Observatory
  Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
  the underlying science of space weather
Conquest Graphics
  for out-of-this-world printing and graphics
Science Central
  more links...
©2010 All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2019 All rights reserved.