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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 404.1 km/sec
density: 4.2 protons/cm3
explanation | more data
Updated: Today at 2349 UT
X-ray Solar Flares
6-hr max: B5
1957 UT Apr28
24-hr: C1
1251 UT Apr28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 Apr 16
Sunspots AR2536 and AR2537 are growing rapidly, but they do not yet pose a threat for strong flares. Credit: SDO/HMI

Sunspot number: 86
What is the sunspot number?
Updated 28 Apr 2016

Spotless Days
Current Stretch: 0 days
2016 total: 0 days (0%)
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 Apr 2016


The Radio Sun
10.7 cm flux: 93 sfu
explanation | more data
Updated 28 Apr 2016

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: 3.5 nT
Bz: 0.5 nT north
explanation | more data
Updated: Today at 2349 UT
Coronal Holes: 28 Apr 16
Solar wind flowing from this small coronal hole could reach Earth on May 1-2. Credit: SDO/AIA.
Noctilucent Clouds The southern season for noctilucent clouds began on Dec. 13, 2015. It is expected to end in late February or March 2016.
Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, Polar
Updated at: 02-12-2016 16:55:02
SPACE WEATHER
NOAA Forecasts
Updated at: 2016 Apr 28 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: 2016 Apr 28 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
40 %
35 %
MINOR
20 %
20 %
SEVERE
05 %
05 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
25 %
30 %
SEVERE
60 %
55 %
 
Thursday, Apr. 28, 2016
What's up in space
       
 

On May 9th, the planet Mercury will pass in front of the sun, producing an inky-black spot on the solar disk. Catch it live on the Internet, courtesy of the Coca-Cola Space Science Center in Columbus, Georgia.

 

SOLAR SECTOR BOUNDARY CROSSING (UPDATED): On April 29th or 30th, Earth will cross a fold in the heliospheric current sheet--a vast wavy structure in interplanetary space separating regions of opposite magnetic polarity. This is called a "solar sector boundary crossing," and it could trigger geomagnetic activity around Earth's poles. NOAA forecasters estimate a 60% chance of G1-class geomagnetic storms when the crossing occurs. Aurora alerts: text or voice

SPACE LIGHTNING OVER TEXAS: High above Earth in the realm of meteors and noctilucent clouds, a strange and beautiful form of lightning dances at the edge of space. Researchers call the bolts "sprites." They are red, fleeting, and tend to come in bunches. Last night in Hawley, Texas, Kevin Palivec photographed a magnificent display over an advancing thunderstorm:

"Storms moving across Texas produce more than just rain,wind,hail and tornados!" says Palivec. "They also produce a lot of space lightning called sprites. This is a stacked image of all the sprites I caught over storms as they moved across Texas towards Dallas/FtWorth--with one meteor thrown in!"

Because sprites are associated with thunderstorms, they tend to occur in late spring and summer. Palivec's photo shows that sprite season is now underway.

"Sprites are a true space weather phenomenon," explains lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain. "They develop in mid-air very high above Earth's surface, around 80 km altitude, growing in both directions, first down, then up. An individual sprite lasts only around 5-50 milliseconds but a sequence of them can be seen to 'dance' over storm fronts for a much longer period of time."

Some researchers believe they are linked to cosmic rays: subatomic particles from deep space striking the top of Earth's atmosphere produce secondary electrons that, in turn, could provide the spark that triggers sprites.

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

PENGUINS SERENADE AURORAS: As northern summer approaches, the midnight skies of the Arctic Circle are no longer completely dark. Aurora season is therefore shifting from north to south. For the next four months or so, the velvety-dark skies of Antarctica are the perfect backdrop for auroras. Penguins on the Brunt Ice Shelf serenaded this display on April 16th:

"I camped out in the field, enduring temperatures around -32°C to -34°C to witnessthis fantastic glow of green and purple," says photographer Greig Lawson. "This is at the site of an Emperor penguin colony. The calls of the birds in the background provided the soundtrack to the evening's photography!"

Lawson is a medical doctor working at the British Antarctic Survey's Halley Research Station. Located atop the Brunt Ice Shelf, a 130 meter thick slab of frozen water that floats atop the Weddell Sea, Halley is known for its studies of ozone, cosmic rays, and climate change. Lawson will be busy in the months ahead tending to the station's wintertime staff of 16. Hopefully, he'll have time send more pictures as geomagnetic storms paint their colors on Antarctic skies. Aurora alerts: text or voice

Realtime Aurora Photo Gallery


Realtime Space Weather 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. 28, 2016, the network reported 9 fireballs.
(8 sporadics, 1 April rho Cygnid)

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 28, 2016 there were 1695 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2016 GC222
Apr 24
14 LD
31 m
2016 HO
Apr 24
2.1 LD
31 m
2016 FY3
Apr 25
6.4 LD
310 m
2001 VG5
Apr 28
52.4 LD
1.8 km
2016 HK
May 1
4.6 LD
47 m
2014 US115
May 1
9.4 LD
52 m
2016 HD3
May 2
2.2 LD
12 m
2016 HN
May 4
12.4 LD
145 m
2008 TZ3
May 5
13.1 LD
355 m
2014 JG55
May 8
7.6 LD
7 m
2016 GS2
May 18
3.4 LD
109 m
2009 DL46
May 24
6.2 LD
215 m
1997 XF11
Jun 10
70 LD
1.8 km
2015 XZ378
Jun 13
9.7 LD
16 m
2009 CV
Jun 20
12.4 LD
60 m
2010 NY65
Jun 24
10.7 LD
215 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.
  Cosmic Rays in the Atmosphere
Situation Report -- Oct. 30, 2015 Stratospheric Radiation (+37o N)
Cosmic ray levels are elevated (+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month.
Sept. 06: 4.14 uSv/hr (414 uRad/hr)
Sept. 12: 4.09 uSv/hr (409 uRad/hr)
Sept. 23: 4.12 uSv/hr (412 uRad/hr)
Sept. 25: 4.16 uSv/hr (416 uRad/hr)
Sept. 27: 4.13 uSv/hr (413 uRad/hr)
Oct. 11: 4.02 uSv/hr (402 uRad/hr)
Oct. 22: 4.11 uSv/hr (411 uRad/hr)
These measurements are based on regular space weather balloon flights: learn more.

Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. For example, here is the data from a flight on Oct. 22, 2015:

Radiation levels peak at the entrance to the stratosphere in a broad region called the "Pfotzer Maximum." This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level.

Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in about 5 hours.

The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners.

  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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