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Solar wind
speed: 333.6 km/sec
density: 1.8 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: C1
1701 UT Apr07
24-hr: C3
1600 UT Apr07
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 07 Apr 13
Sunspots AR1713 and AR1718 have beta-gamma magnetic fields that harbor energy for M-class solar flares. Credit: SDO/HMI
Sunspot number: 117
What is the sunspot number?
Updated 07 Apr 2013

Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
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

07 Apr 2013

The Radio Sun
10.7 cm flux: 137 sfu
explanation | more data
Updated 07 Apr 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 5.4 nT
Bz: 3.8 nT north
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 07 Apr 13
Solar wind flowing from the indicated coronal hole is brushing against Earth's magnetic field this weekend. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2013 Apr 07 2200 UTC
0-24 hr
24-48 hr
30 %
30 %
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: 2013 Apr 07 2200 UTC
0-24 hr
24-48 hr
20 %
20 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
15 %
30 %
30 %
25 %
25 %
Sunday, Apr. 7, 2013
What's up in space

Listen to radar echoes from satellites and meteors, live on listener-supported Space Weather Radio.

Spaceweather Radio is on the air

WEEKEND AURORAS: A weak solar wind stream is brushing against Earth's magnetic field this weekend. In response to the encounter, NOAA forecasters put the odds of a polar geomagnetic storm on April 7 at 30%. High-latitude sky watchers should be alert for auroras. Aurora alerts: text, voice.

DAYLIGHT CONJUNCTION: There's an alignment of planets today, but don't bother looking because the conjunction is happening in broad daylight. Venus and Mars have converged only 1o apart in close proximity to the sun:

The image above comes from SOHO, the Solar and Heliospheric Observatory. SOHO is able to monitor the encounter using coronagraphs to block the sun's blinding glare.

Mars and Venus will begin to separate later today. Venus will move away from the sun, while Mars will move in even closer. This could cause problems for NASA when it tries to contact Mars rovers and orbiters. According to a NASA press release, "The sun can easily disrupt radio transmissions during the near-alignment. To prevent an impaired command from reaching an orbiter or rover, mission controllers at the Jet Propulsion Laboratory are preparing to suspend sending any commands to spacecraft at Mars for weeks in April. Transmissions from Mars to Earth will also be reduced." Mars will be at its closest to the sun, a slim 0.4 degrees on April 17th.

The ongoing dance of the sun and planets is invisible to the human eye, but coronagraphs can see the show. Join SOHO for a ringside seat.

Realtime Space Weather Photo Gallery

OMG: On April 4th, in the western sky at sunset, Comet Pan-STARRS made a photogenic flyby of the Andromeda galaxy. Amateur astronomer Pavel Smilyk of Syktyvkar, Russia, photographed the pair at the hour of closest approach:

"This is a 27 x 2 minute guided exposure I made using a Canon 1100Da digital camera," says Smilyk. "We had very clear skies."

In this deep exposure, the comet's dusty tail appears to touch the galaxy's outermost spiral arms. In fact, no physical contact occured; the comet is still in the solar system while Andromeda is 2.5 million light years away.

The comet and galaxy are parting now, but slowly, so they will remain a close pair for cameras and wide-field telescopes for several nights to come. Browse the gallery for more close-up images of the ongoing conjunction.

More about Pan-STARRS: NASA video, 3D orbit, ephemeris, light curves.

Realtime Comet Photo Gallery

Realtime Aurora Photo Gallery

Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]

  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, 2013 there were 1391 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2010 GM23
Apr 13
3.9 LD
50 m
2005 NZ6
Apr 29
24.9 LD
1.3 km
2001 DQ8
Apr 30
74.3 LD
1.1 km
2004 BV102
May 25
69.9 LD
1.4 km
1998 QE2
May 31
15.2 LD
2.1 km
2000 FM10
Jun 5
50.3 LD
1.3 km
2002 KL3
Jun 6
66.4 LD
1.1 km
1999 WC2
Jun 12
39.2 LD
1.9 km
2006 RO36
Jun 18
70.9 LD
1.2 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
Space Weather Alerts
  more links...
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