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Solar wind
speed: 371.0 km/sec
density: 10.6 protons/cm3
explanation | more data
Updated: Today at 2349 UT
X-ray Solar Flares
6-hr max: B4
2257 UT May28
24-hr: B4
2257 UT May28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 May 15
Not one of these sunspots poses a threat for strong flares. Solar activity is very low. Credit: SDO/HMI

Sunspot number: 24
What is the sunspot number?
Updated 28 May 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 28 May 2015


The Radio Sun
10.7 cm flux: 95 sfu
explanation | more data
Updated 28 May 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 6.2 nT
Bz: 2.9 nT north
explanation | more data
Updated: Today at 2350 UT
Coronal Holes: 28 May 15

Solar wind flowing from this minor coronal hole should reach Earth on May 29-30. Credit: SDO/AIA.
Noctilucent Clouds The northern season for NLCs is about to begin. Readers should monitor the "daily daisies" below for first sightings from NASA's AIM spacecraft.
Switch view: Europe, USA, Asia, Polar
Updated at: 05-23-2015 15:55:02
SPACE WEATHER
NOAA Forecasts
Updated at: 2015 May 28 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
05 %
05 %
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 May 28 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
25 %
20 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
30 %
30 %
SEVERE
30 %
25 %
 
Thursday, May. 28, 2015
What's up in space
 

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Chase the Light Tours

QUIET WITH A SLIGHT CHANCE OF STORMS: NOAA forecasters estimate a 30% chance of polar geomagnetic storms on May 29th when a minor solar wind stream is expected to hit Earth's magnetic field. Otherwise, solar and geomagnetic activity is very low. Aurora alerts: text, voice

NOCTILUCENT CLOUDS OVER SCOTLAND: The northern summer season for noctilucent clouds (NLCs) is underway. Earth-orbiting satellites such as AIM and the International Space Station have been photographing the electric-blue clouds for days. Last night, sky watchers on Earth saw them, too. M. J. S. Ferrier sends this picture from Barassie Beach in Ayrshire, Scotland:

The fine-structured blue clouds floating above the dark, ordinary storm clouds are the NLCs. "It was hard to tell the full extent of the display due to a storm system passing through," says Ferrier. "But the noctilucent clouds were definitely there." Jimmy Fraser of Alness, Scotland, also photographed the display. "It was a great start for the NLC season here in northern Scotland," says Fraser.

NLCs are Earth's highest clouds. Seeded by meteoroids, they float at the edge of space more than 80 km above the planet's surface. The clouds are very cold and filled with tiny ice crystals. When sunbeams hit those crystals, they glow electric-blue.

Noctilucent clouds first appeared in the 19th century after the eruption of super-volcano Krakatoa. At the time, people thought NLCs were caused by the eruption, but long after Krakatoa's ash settled, the clouds remained. In recent years, NLCs have intensified and spread with sightings as far south as Utah and Colorado. This could be a sign of increasing greenhouse gases in Earth's atmosphere.

Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.

Realtime NLC Photo Gallery

RADAR ECHOES FROM THE NOCTILUCENT ZONE: Every summer since the late 1970s, radars probing Earth's upper atmosphere have detected strong echoes from altitudes between 80 km and 90 km. These altitudes comprise the "noctilucent zone," where water vapor crystallizes around meteor smoke to form icy noctilucent clouds (NLCs). The first NLCs of the 2015 northern summer season were spotted by NASA's AIM spacecraft on May 19th. The radar echoes have followed close behind.

Les Dean of the MST Radar Facility in Aberystwyth, Wales, reports: "We detected our first echoes of the summer season on May 26th."

Researchers call them "Polar Mesospheric Summer Echoes" or "PMSEs." They occur over the Arctic during the months of May through August, and over the Antarctic during the months of November through February. These are the same months that NLCs appear.

But do the radar echoes actually come from noctilucent clouds? "The association is controversial," notes Dean. A leading theory holds that the ice particles in noctilucent clouds are electrically charged, and this makes them good reflectors of HF radio waves. However, NLCs are not always visible when the radar echoes are observed and vice versa. So the connection is not clear-cut.

One thing is sure: the northern season for both NLCs and PMSEs has begun. Stay tuned for more echoes from the noctilucent zone.

UPDATE: "What is happening 90 km above Earth's surface?" wonders researcher Rob Stammes at the Polarlightcenter in Lofoten, Norway. For the past two nights, he has detected intense radio reflections using a forward scatter meteor radar. The phenomenon is almost surely linked to the PMSEs and noctilucent clouds reported above.

Realtime Space Weather Photo Gallery

SPRITES OVER OKLAHOMA: On Saturday night, May 23rd, strong thunderstorms raked Texas and Oklahoma, producing torrential rains and deadly floods. Amateur astronomer Thomas Ashcraft could see the lightning bolts all the way from New Mexico--and not all of them were going down. "There was a bright display of sprites shooting up from the tops of the thunderclouds," says Ashcraft. He took this picture using a near-infrared camera at his observatory outside Santa Fe:

Sprites are an exotic form of lightning that appear very high above Earth's surface, at the edge of space itself.

"Sprites are a true space weather phenomenon," says lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain. "They develop in mid-air around 80 km altitude, growing in both directions, first down, then up. This happens when a fierce lightning bolt draws lots of charge from a cloud near Earth's surface. Electric fields [shoot] to the top of Earth's atmosphere--and the result is a sprite."

How exotic are they? This close-up view of the Oklahoma sprites says it all:

"Turn up the volume," advises Ashcraft. "In the movie you can hear the very low frequency radio crackles from individual lightning strokes."

Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now "sprite chasers" routinely photograph sprites from their own homes. Give it a try.

Realtime Sprite Photo Gallery


Realtime Aurora 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 May. 28, 2015, the network reported 24 fireballs.
(24 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 May 28, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2015 KY56
May 25
5.7 LD
21 m
2015 HT9
May 25
12.1 LD
28 m
2015 KP57
May 28
10.4 LD
44 m
2015 KW120
May 29
1.1 LD
27 m
2015 KH
May 29
14.3 LD
53 m
2015 KQ120
May 31
8.5 LD
19 m
2015 KM57
Jun 3
6.6 LD
34 m
2005 XL80
Jun 4
38.1 LD
1.0 km
2015 KA122
Jun 6
3.3 LD
95 m
2015 KU121
Jun 7
7.5 LD
109 m
2012 XB112
Jun 11
10.1 LD
2 m
2015 KK57
Jun 23
8.3 LD
13 m
2005 VN5
Jul 7
12.6 LD
18 m
2015 HM10
Jul 7
1.1 LD
73 m
1994 AW1
Jul 15
25.3 LD
1.4 km
2011 UW158
Jul 19
6.4 LD
565 m
2013 BQ18
Jul 20
7.9 LD
38 m
1999 JD6
Jul 25
18.8 LD
1.6 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
Space Weather Alerts
   
  more links...
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