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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 494.4 km/sec
density: 20.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0005 UT
X-ray Solar Flares
6-hr max: B1
2343 UT Apr19
24-hr: C1
0000 UT Apr19
explanation | more data
Updated: Today at: 2359 UT
Daily Sun: 19 Apr 17
Old sunspot AR2644 has returned and been renumbered AR2651. It is crackling with C-class solar flares. Credit: SDO/HMI

Sunspot number: 12
What is the sunspot number?
Updated 19 Apr 2017

Spotless Days
Current Stretch: 0 days
2017 total: 30 days (27%)
2016 total: 32 days (9%)
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 19 Apr 2017


The Radio Sun
10.7 cm flux: 80 sfu
explanation | more data
Updated 19 Apr 2017

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 5
storm
explanation | more data
Interplanetary Mag. Field
Btotal: 12.6 nT
Bz: -12.1 nT south
more data: ACE, DSCOVR
Updated: Today at 0005 UT
Coronal Holes: 19 Apr 17

Solar wind flowing from the indicated coronal hole should reach Earth on April 18-19. Credit: NASA/SDO.
Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17, 2016. Come back to this spot every day to see the "daily daisy" from NASA's AIM spacecraft, which is monitoring the dance of electric-blue around the Antarctic Circle.
Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, Polar
Updated at: 02-24-2017 17:55:02
SPACE WEATHER
NOAA Forecasts
Updated at: 2017 Apr 19 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
10 %
10 %
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: 2017 Apr 19 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
40 %
25 %
MINOR
15 %
10 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
15 %
MINOR
25 %
25 %
SEVERE
50 %
35 %
 
Wednesday, Apr. 19, 2017
What's up in space
       
 

Looking for a far-out Mother's Day gift? Find something truly out of this world in the Earth to Sky Store. Space roses, Cosmic Reindeer, Arctic space pendants, and more!

 

ASTEROID FLYBY TODAY: Approaching from the direction of the sun, mountain-sized asteroid 2014 JO25 is flying past Earth today, April 19th, approximately 1.8 million km away. NASA says there is no danger of a collision, but it is close enough for amateur astronomers to photograph in backyard telescopes. It looks like a fast-moving speck of light (magnitude +11) zipping among the stars. Canadian astrophotographer Mario Hebert used a 10-inch telescope at the Parc national de la Mauricie in Quebec to capture this movie of 2014 JO25 nearing Earth on April 18th. Got an image? Submit it here.

SPECTACULAR CME: Old sunspot AR2644 has returned--and it is still active. On April 18th at approximately 2000 UT, the sunspot's magnetic canopy exploded and hurled a bright coronal mass ejection (CME) into space. The ESA/NASA Solar and Heliophysics Observatory caught the cloud as it raced away from the sun:

This CME will probably miss Earth. The explosion's epicenter was too far off the Sun-Earth line for a direct hit. NOAA analysts are still evaluating the possibility of a glancing blow, however, so stay tuned for updates.

More CMEs may be in the offing. In early April this sunspot produced a series of strong M-class flares and shortwave radio blackouts on Earth. Geoeffective activity stopped only when the sunspot went into hiding on the farside of the sun. Two weeks later it's back, and it is turning toward Earth for a new round of solar activity.

Note: By longstanding tradition, sunspots that travel around the backside of the sun and re-appear are renumbered. AR2644 therefore has a new designation: AR2651. We will use both names in our coverage of this active region in the days ahead.

Realtime Aurora Photo Gallery

SCINTILLATING SIRIUS: Sirius is the brightest star in the sky. It is also, arguably, the most colorful.  On any given evening of northern Spring, sky watchers can behold a spray of rainbow colors emanating from the Dog Star as it sets low in the southwestern sky. Tom Wagner of Waterloo, Iowa, has developed a beautiful way to display the star's hue. "Decades ago I discovered that by wiggling my binoculars while looking at Sirius, I could easily see the colors of the rainbow flash by in rapid succession." On April 16th he took this picture through the eyepiece:

"This is a 2 second exposure," he says.  "The colors were spectacular!"

Astronomers call this phenomenon "scintillation." Also known as "twinkling," the phenomenon is caused by thermal irregularities in Earth's atmosphere.  As packets of relatively warm and cool air drift in front of a star, the star's light is refracted. The prismatic action of these air packets produce rainbow colors--especially near the horizon where starlight must pass through many turbulent irregularities to reach the observer. 

All stars scintillate, but Sirius does so most flamboyantly because of its extreme brightness. See for yourself.  Step outside this evening after sunset and look southwest for Sirius near the feet or Orion.  The lower it gets, the more it twinkles. Enjoy the show!

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. 19, 2017, the network reported 10 fireballs.
(10 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 19, 2017 there were 1798 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Velocity (km/s)
Diameter (m)
2017 GO4
2017-Apr-15
13.8 LD
6
34
2014 UR
2017-Apr-19
18.8 LD
4.4
17
2014 JO25
2017-Apr-19
4.6 LD
33.6
852
2017 GL4
2017-Apr-20
17.5 LD
7.4
22
2017 GM4
2017-Apr-20
13.1 LD
16.6
143
2017 FH101
2017-Apr-24
18.8 LD
9.9
103
2017 FE157
2017-Apr-29
18.6 LD
8.6
64
2015 VD1
2017-May-07
18.2 LD
10.5
34
2012 EC
2017-May-16
19.5 LD
4.5
74
2017 CS
2017-May-29
8 LD
9.1
468
418094
2017-Jun-01
8 LD
23.2
490
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

Readers, thank you for your patience while we continue to develop this new section of Spaceweather.com. We've been working to streamline our data reduction, allowing us to post results from balloon flights much more rapidly, and we have developed a new data product, shown here:

This plot displays radiation measurements not only in the stratosphere, but also at aviation altitudes. Dose rates are expessed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x. These measurements are made by our usual cosmic ray payload as it passes through aviation altitudes en route to the stratosphere over California.

What is this all about? 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. Furthermore, there are studies ( #1, #2, #3, #4) linking cosmic rays with cardiac arrhythmias and sudden cardiac death in the general population. Our latest measurements show that cosmic rays are intensifying, with an increase of more than 12% since 2015:


Why are cosmic rays intensifying? The main reason is the sun. Solar storm clouds such as coronal mass ejections (CMEs) sweep aside cosmic rays when they pass by Earth. During Solar Maximum, CMEs are abundant and cosmic rays are held at bay. Now, however, the solar cycle is swinging toward Solar Minimum, allowing cosmic rays to return. Another reason could be the weakening of Earth's magnetic field, which helps protect us from deep-space radiation.

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.

The data points in the graph above correspond to the peak of the Reneger-Pfotzer maximum, which lies about 67,000 feet above central California. When cosmic rays crash into Earth's atmosphere, they produce a spray of secondary particles that is most intense at the entrance to the stratosphere. Physicists Eric Reneger and Georg Pfotzer discovered the maximum using balloons in the 1930s and it is what we are measuring today.

  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
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NOAA 27-Day Space Weather Forecasts
  fun to read, but should be taken with a grain of salt! Forecasts looking ahead more than a few days are often wrong.
Aurora 30 min forecast
  from the NOAA Space Environment Center
Heliophysics
  the underlying science of space weather
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