You are viewing the page for Apr. 15, 2015
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids Internet Shopping Sites high quality binoculars excellent weather stations all-metal reflector telescopes rotatable microscopes
Solar wind
speed: 565.6 km/sec
density: 5.8 protons/cm3
explanation | more data
Updated: Today at 2342 UT
X-ray Solar Flares
6-hr max: C7
2023 UT Apr15
24-hr: C7
2023 UT Apr15
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 15 Apr 15
Sunspot AR2321 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 97
What is the sunspot number?
Updated 15 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 15 Apr 2015

The Radio Sun
10.7 cm flux: 141 sfu
explanation | more data
Updated 15 Apr 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 5 storm
24-hr max: Kp= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 6.3 nT
Bz: 4.4 nT north
explanation | more data
Updated: Today at 2348 UT
Coronal Holes: 15 Apr 15

Earth is entering a stream of solar wind flowing from the indicated coronal hole. 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
NOAA Forecasts
Updated at: 2015 Apr 15 2200 UTC
0-24 hr
24-48 hr
40 %
55 %
10 %
20 %
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 15 2200 UTC
0-24 hr
24-48 hr
35 %
20 %
15 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
20 %
30 %
25 %
45 %
25 %
Wednesday, Apr. 15, 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

GEOMAGNETIC STORM: A minor geomagnetic storm is underway as Earth enters a hgh-speed stream of solar wind. Forecasters espect these storm continues to continue through April 16th. High-latitude sky watchers should be alert for auroras. Aurora alerts: text, voice

TWILIGHT AURORAS: Around the Arctic Circle, night is vanishing as the summer sun rises over the polar realm. This is creating a short-lived mixture of colors in the sky: aurora green and twilight blue. Truls Tiller sends this picture of the phenomenon from Tromsø City, Norway:

"On April 15th, the 'night' sky was almost daylight, but the auroras were visible anyway," says Tiller. "These could be the last aurora photos from Tromsø until autumn, because of the light and the sun, but we will be back."

Actually, they are probably the second-to-last. The ongoing geomagnetic storm could add one more dash of green to the twilight before the Arctic sun finally overwhelms the Northern Lights. Monitor the aurora gallery for last-chance sightings.

Realtime Aurora Photo Gallery

EXTRAORDINARY STRETCH: On April 14th, an unstable filament of magnetism rose up and erupted from the sun's eastern limb. This image from NASA's Solar Dynamics Observatory shows the first moments of a very high-rising prominence:

The magnetic loop shown above quickly exited SDO's field of view. It kept going ... and going... until it stretched itself out almost 700,000 km long. In East Devon, UK, amateur astronomer David Strange was monitoring the sun and witnessed the extraordinary stretch through the eyepiece of a backyard solar telecope. French astrophotographer Sylvain Weiller saw it, too. For comparison, the prominence was half the diameter of the sun and twice as long as the distance between Earth and the Moon. "It went to an unbelievable height," says Weiller.

Part of the prominence snapped off and formed the core of a bright CME: movie. The expanding cloud billowed away from the sun's eastern limb, well off the sun-Earth line, and is not expected to hit our planet. Solar flare alerts: text, voice

Realtime Space Weather Photo Gallery

Realtime Eclipse 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

On Apr. 15, 2015, the network reported 18 fireballs.
(18 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 15, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2005 KA
Apr 12
13 LD
50 m
2015 GE1
Apr 13
3.4 LD
31 m
2015 GL
Apr 13
6 LD
40 m
2015 GB1
Apr 13
6 LD
20 m
2015 GK
Apr 13
2.8 LD
30 m
2015 GA1
Apr 16
2.5 LD
21 m
2015 GY12
Apr 19
13.7 LD
31 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
2005 VN5
Jul 7
12.6 LD
18 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.
  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...
©2010 All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2019 All rights reserved.