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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 418.3 km/sec
density: 0.1 protons/cm3
explanation | more data
Updated: Today at 2342 UT
X-ray Solar Flares
6-hr max: C1
2013 UT Apr28
24-hr: C1
0901 UT Apr28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 Apr 12
New sunspots are emerging at the circled location. Credit: SDO/HMI
Sunspot number: 99
What is the sunspot number?
Updated 27 Apr 2012

Spotless Days
Current Stretch: 0 days
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days

Updated 27 Apr 2012


The Radio Sun
10.7 cm flux: 118 sfu
explanation | more data
Updated 27 Apr 2012

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 2.1 nT
Bz: 2.1 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 28 Apr 12
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2012 Apr 28 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
20 %
20 %
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: 2012 Apr 28 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
 
Saturday, Apr. 28, 2012
What's up in space
 

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CHANCE OF FLARES: Sunspot AR1465 has developed a 'beta-gamma-delta' magnetic field that harbors energy for strong flares. NOAA forecasters estimate a 20% chance of M-class eruptions during the next 24 hours. Because the active region is located on the Earthside of the sun, any flares from AR1465 will likely be geoeffective.

Even without a strong eruption from AR1465, ionization waves are already rippling through Earth's upper atmosphere. Dave Gradwell of Birr, Ireland, recorded a series of sudden ionospheric disturbances (SIDs) on April 27th:

Low-level flares from several sunspot groups (especially 1465, 1466 and 1467) are strobing the atmosphere with ionizing radiation. Using a VLF receiver, Gradwell detected their effect on the propagation of radio signals transmitted from France. So far the disturbances have been relatively weak, but this could change if AR1465 unleashes a more potent eruption over the weekend. Solar flare alerts: text, phone.

FIREBALL PHOTOS WANTED: Meteor expert Peter Jenniskens of NASA's Ames Research Center could use some help from the general public--in particular, photographers and business owners with security cameras in central California. He needs photos of the mini-van sized asteroid that exploded over the region on Sunday morning, April 22nd, at 7:51 am PDT. "Our goal is to determine the orbit of the object and to understand how this small asteroid fell apart when it entered the earth's atmosphere," he explains. [Got photos? Submit them here.]

Meteorite hunters, Jenniskens included, are starting to find pieces of the asteroid on the the ground. These samples were lying in the parking lot of Henningsen-Lotus Park, apparently crushed by a passing car:

The meteorites landed not far from Sutter's Mill in El Dorado County, CA, the same place gold was discovered in the 19th century, triggering the California Gold Rush. Jenniskens likens the thrill of finding these space rocks to finding gold: " I think John A. Sutter must have felt the same way when he found the first gold nugget back in January of 1848."

"The meteorites appear to be CM chondrites," he continues. This would make the sample very primitive, possibly contiaining minerals and compounds preserved from a time when the solar system was very young. "I can not say more as the samples have not yet been analyzed. My main concern now is to recover perishable data of the fireball, such as video security camera footage."

More footage will help researchers answer questions like these: "Was this a rubble pile or a monolitihic block? Was the orbit very evolved, or could its semi-major axis perhaps still point us to the source region of CM chondrites in the asteroid belt?" Jeniskens wonders. "This is a rare opportunity to learn about the properties of a particular class of near-Earth objects."

News reports: #1, #2, #3.

  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 28, 2012 there were 1287 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2012 HE2
Apr 24
8.9 LD
--
28 m
2012 HQ
Apr 24
9.8 LD
--
42 m
2012 HP13
Apr 27
2 LD
--
64 m
2012 HM
Apr 28
1.4 LD
--
67 m
2011 WV134
Apr 28
38.6 LD
--
1.6 km
1992 JD
May 2
9.5 LD
--
43 m
2010 KK37
May 19
2.3 LD
--
31 m
4183 Cuno
May 20
47.4 LD
--
5.7 km
2002 VX94
May 26
72.8 LD
--
1.1 km
2002 AC
Jun 16
62.2 LD
--
1.2 km
1999 BJ8
Jun 16
68.8 LD
--
1.1 km
2005 GO21
Jun 21
17.1 LD
--
2.2 km
2003 KU2
Jul 15
40.3 LD
--
1.3 km
2004 EW9
Jul 16
46.8 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 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
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