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Solar wind
speed: 452.8 km/sec
density: 5.9 protons/cm3
explanation | more data
Updated: Today at 2259 UT
X-ray Solar Flares
6-hr max: C2
2116 UT Apr20
24-hr: C2
2116 UT Apr20
explanation | more data
Updated: Today at: 2256 UT
Daily Sun: 20 Apr 15
Sunspot AR2321 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 142
What is the sunspot number?
Updated 20 Apr 2015

Spotless Days
Current Stretch: 0 days
2015 total: 0 days (0%)

2014 total: 1 day (<1%)
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%)

Updated 20 Apr 2015


The Radio Sun
10.7 cm flux: 152 sfu
explanation | more data
Updated 20 Apr 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 3
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 5.0 nT
Bz: 0.1 nT north
explanation | more data
Updated: Today at 2300 UT
Coronal Holes: 20 Apr 15

Solar wind flowing from the indicated coronal hole should reach Earth on April 22. Credit: SDO/AIA.
Noctilucent Clouds The southern season for NLCs has come to an end. The last clouds were observed by NASA's AIM spacecraft on Feb. 20, 2015. Now attention shifts to the northern hemisphere, where the first clouds of 2015 should appear in mid-May.
Switch view: Ross Ice Shelf, Antarctic Penninsula, East Antarctica, Polar
Updated at: 02-28-2015 02:55:03
SPACE WEATHER
NOAA Forecasts
Updated at: 2015 Apr 20 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
15 %
15 %
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: 2015 Apr 20 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
45 %
45 %
MINOR
35 %
25 %
SEVERE
10 %
05 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
05 %
05 %
MINOR
20 %
20 %
SEVERE
75 %
65 %
 
Monday, Apr. 20, 2015
What's up in space
 

Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park.

 
Lapland tours

SUNSET SKY SHOW: When the sun goes down tonight, look west into the sunset. The slender cresent Moon is approaching Venus from below. Try to catch them before the sky fades to black. Venus and the Moon look especially beautiful when they are framed by twilight blue. [photo gallery]

INCOMING CME, STORMS POSSIBLE ON EARTH DAY: On Saturday, April 18th, a magnetic filament attached to sunspot group AR2321 erupted, producing a C5-class solar flare. NASA's Solar Dynamics Observatory watched the filament split the sun's atmosphere as it hurtled away from the blast site:

Part of the escaping filament formed the core of a faint CME, which is now heading almost directly for Earth. The cloud should reach our planet during the late hours of April 21st. In combination with a solar wind stream already en route, the impact could spark geomagnetic storms around the poles on April 22nd, Earth Day.

This is a minor CME launched by a minor C-class flare, so it is natural to expect only minor storms when the CME arrives. Indeed, that is probably what will happen. It is notable, however, that the intense geomagnetic storm of March 17, 2015, was triggered by a C-flare/CME combo only a little more intense than this one. The "St. Patrick's Day Storm" reminds us that any CME impact can produce a significant disturbance. Indeed, NOAA forecasters estimate a 65% chance of polar magnetic storms when the CME arrives. Auroras for Earth Day, anyone? Stay tuned. Aurora alerts: text, voice.

Realtime Aurora Photo Gallery

SPACE YEAST MAKES SPACE BREAD: Thought experiment: Suppose you flew a packet of baker's yeast high above Earth's surface, to the edge of space itself, and exposed the microbes to a blast of cosmic rays. Then you made some bread. How would it taste? "It is delicious," reports Eileen Weingram of Highland Lakes, NJ, who actually did the experiment:

On March 17th, during the strongest geomagnetic storm of the current solar cycle, the students of Earth to Sky Calculus flew a Space Weather Buoy to the stratosphere. Along with radiation detectors and other sensors, the payload carried packets of brewer's and baker's yeast. En route to the stratosphere, the microbes experienced temperatures as low as -63 C and cosmic ray doses 40x Earth-normal.

To support the students' research, Eileen Weingram bought a packet of the baker's yeast. "It made a huge loaf of bread," she says. "Very yummy."

If this story whets your appetite, you can bake some "space bread" of your own. Packets of yeast are still available for only $49.95. Contact Dr. Tony Phillips to place your order--and let the baking begin! All sales support high altitude balloon flights to measure the effect of solar storms on Earth's atmosphere.

Realtime Space Weather Photo Gallery

LYRID METEOR SHOWER: Earth is entering a stream of debris from Comet Thatcher, source of the annual Lyrid meteor shower. If forecasters are correct, the shower will peak on April 22-23 with 10 to 20 meteors per hour. Sky watchers are already seeing some early arrivals. Dan Bush photographed this Lyrid fireball over Albany, Missouri, before sunrise on April 20th:

"I captured an early Lyrid meteor in two of my all sky cameras," reports Bush. "This is a 1 minute image stack. The brighter streak in the east from behind the tree is the trail of an airplane."

Reports of Lyrids have also been received from Mexico and Washington state.

The Lyrid meteor shower is usually mild, and this year may be no exception. Nevertheless, these early sightings could herald a nice display. The best time to look is between about 11 pm on April 22nd and sunrise on April 23rd. [sky map]

Observing tips: Dress warmly. Bring a reclining chair, or spread a thick blanket over a flat spot of ground. Lie down and look up. Meteors can appear in any part of the sky, although their trails will tend to point back toward the constellation Lyra, from which the meteors get their name.  The hours before dawn are best, because that is when Lyra is highest in the sky.

Realtime Meteor Photo Gallery


Realtime Comet Photo Gallery


  All Sky Fireball Network

Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com.

On Apr. 20, 2015, the network reported 51 fireballs.
(51 sporadics)

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]

  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 20, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2015 GA1
Apr 16
2.5 LD
21 m
2015 GL13
Apr 16
0.5 LD
8 m
2015 GY12
Apr 19
13.7 LD
31 m
2015 HE1
Apr 21
3.3 LD
16 m
2015 HD1
Apr 21
0.2 LD
15 m
2015 GB14
Apr 28
8.9 LD
38 m
5381 Sekhmet
May 17
62.8 LD
2.1 km
2005 XL80
Jun 4
38.1 LD
1.0 km
2012 XB112
Jun 11
10.1 LD
2 m
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
Space Weather Alerts
   
  more links...
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