You are viewing the page for Apr. 11, 2011
  Select another date:
<<back forward>>
SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 454.7 km/sec
density: 5.1 protons/cm3
explanation | more data
Updated: Today at 2345 UT
X-ray Solar Flares
6-hr max: C1
2030 UT Apr11
24-hr: C1
2030 UT Apr11
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 11 Apr 11
Neither of these sunspots poses a threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 56
What is the sunspot number?
Updated 10 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 10 Apr 2011


The Radio Sun
10.7 cm flux: 105 sfu
explanation | more data
Updated 10 Apr 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 4
unsettled
explanation | more data
Interplanetary Mag. Field
Btotal: 11.4 nT
Bz: 11.3 nT north
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 11 Apr 11
A solar wind stream flowing from the indicated coronal hole could brush against Earth's magnetic field during the next 24 hours. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Apr 11 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
01 %
01 %
CLASS X
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 11 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
20 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
25 %
15 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
 
Monday, Apr. 11, 2011
What's up in space
 

They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store.

 
Own your own meteorite

HORSESHOE ASTEROID DISCOVERED: Astronomers from the Armagh Observatory in Northern Ireland have found that recently-discovered asteroid 2010 SO16 has been following Earth around the Sun for more than 250,000 years. Relative to our planet, the asteroid describes a horseshoe-shaped path in space. Strange, but true!

AURORAS IN MOTION: So far, April has been a good month for Northern Lights. Almost every night, bright auroras have been dancing around the Arctic Circle--really dancing. Click on the arrow to view a 5 MB video of auroras in motion over Quebec's Lagrande river on April 7th:

To make the video, photographer Michel Tournay (pictured above) assembled more than 800 pictures taken with his Nikon D3s. "I especially like the moment where the aurora became very intense for a few seconds showing some smoke on the river," says Tourney. "Normally I would have edited out that part because the aurora was over exposed, but I wanted to show how the scenery got illuminated by it!"

More auroras are possible tonight. NOAA forecasters estimate a 40% chance of geomagnetic activity during the next 24 hours, when a solar wind stream is expected to buffet Earth's magnetic field. A coronal mass ejection (movie) detected by NASA's STEREO probes on April 9th could also reach Earth and contribute to a possible display on April 11th. Aurora alerts: voice, text.

April 2011 Aurora Gallery
[previous Aprils: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]

SOLAR NEPHELOCOCCYGIA: It's a noun. Nephelococcygia: The act of seeking and finding shapes in clouds. On April 10th in Selsey, UK, Pete Lawrence set up his solar telescope and performed nephelococcygia on the sun. "I think I found a fish," he says.

The fish-shaped form at the base of the image is a cloud of plasma held above the stellar surface by magnetic fields. It looks dark because it is cooler than the inferno below. Readers with solar telescopes are encouraged to monitor this fishy form--and learn to pronounce nephelococcygia.

more images: from Cai-Uso Wohler of Bispingen, Germany; from Luca Tesoro of Mercogliano, Avellino, Italy


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 11, 2011 there were 1214 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
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
--
28 m
2011 GP59
Apr 15
1.4 LD
--
60 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
2011 GA55
Jul 6
62.9 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.
STEREO
  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
Heliophysics
  the underlying science of space weather
Conquest Graphics
  for out-of-this-world printing and graphics
Science Central
   
  more links...
©2010 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2013 Spaceweather.com. All rights reserved.