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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
SPACE WEATHER
Current conditions
Solar wind
speed: 402.0 km/sec
density: 1.9 protons/cm3
explanation | more data
Updated: Today at 2257 UT
X-ray Solar Flares
6-hr max: A0
2245 UT Apr14
24-hr: A0
2245 UT Apr14
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 13 Apr 08
The small new-cycle sunspot noted by the arrow has not yet received an official number. Credit: SOHO/MDI
Sunspot number: 12
What is the sunspot number?
Updated 14 Apr 2008
Far side of the Sun:
This holographic image reveals no sunspots on the farside of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 1
quiet
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 1.5 nT
Bz: 1.0 nT north
explanation | more data
Updated: Today at 2257 UT
Coronal Holes:
Almost the entire Earth-facing side of the sun is "covered" by a poorly-organized coronal hole. This sometimes happens during solar minimum when the sun's magnetic field relaxes, creating a wide but weak coronal hole that allows solar wind to escape from broad expanses of the sun's atmosphere. Credit: SOHO Extreme UV Telescope
SPACE WEATHER
NOAA Forecasts
Updated at: 2008 Apr 14 2203 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: 2008 Apr 14 2203 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
What's up in Space
April 14, 2008
Where's Saturn? Is that a UFO--or the ISS? What's the name of that star? Get the answers from mySKY--a fun new astronomy helper from Meade.   mySKY

CELESTIAL TRIANGLE: After the sun sets tonight, go outside and look south. You'll see Saturn, the gibbous Moon, and first-magnitude star Regulus gathered together in the form of a scalene triangle: sky map. With the bright Moon to guide your attention, Saturn is easy to find. Got a telescope? Point it at Saturn and behold the planet's rings before they vanish.

PINK AURORAS: "Working at a remote mine in Canada's Northwest Territorry allows us to see auroras regularly," says Lana Rupp, "but April 6th was the first time I've seen so many colors--pink, purple and green." She took this picture of the sky above the mine using her Nikon D40X:


Photo details: Nikon D40X, 10 sec exposure, 400iso, 30mm, f4.5

Why the pink? Auroras are caused by charged particles (mainly electrons) from space raining down on Earth's atmosphere, causing the air to glow where they hit. The most common shade is green; this is the color given off by oxygen 60+ miles above Earth's surface. On April 6th, however, a burst of extra-energetic electrons penetrated the atmosphere deeper than usual reaching altitudes less than 60 miles. For such "low auroras," the temperature and density of air favor not the green glow of oxygen but the pink and purple shades of molecular nitrogen, hence the pink fringe. Learn more about aurora colors from Alaska's Geophysical Inststitute.

April 2008 Aurora Gallery
[Aurora Alerts] [Night-sky Cameras]

HAIL STORM RAINBOW: "April showers bought us a few hail storms this weekend," reports Pete Glastonbury of Devizes, Wiltshire, UK. "One of them produced a rainbow with the hail storm below." He snapped this picture of the sky behind his house:


Photo details: Pentax ist DL, ISO 100, 1/250 sec

Should this be called a "hailbow"? No. Atmospheric optics expert Les Cowley explains that "rainbow" is still the correct word to use:

"Hailstones are too irregular and opaque to make rainbows; This hailstorm had to be mixed with rain," he says. "Rainbows need transparent and almost perfect spheres to refract the sun’s rays, so perfect it seems miraculous that we ever see a rainbow!"

There is a mysterious type of rainbow known as the twinned bow, adds Cowley. "These are somehow associated with hail showers. One theory is that ice spheres inside raindrops form them." Twinned bows may be the true hailbows. Look for them whenever solid rain begins to fall.

more rainbow images: from Alan Friedman of Buffalo NY; from Mila Zinkova of San Francisco, California; from Shawn Malone of Marquette, Michigan; from Denis Joye at the Park of St-Cloud near Paris, France; from Aymen Ibrahem at the Bibliotheca Alexandrina, Alexandria, Egypt; from Eugene Miller at Croton Dam, New York.


 

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. [comment]
On April 14, 2008 there were 947 potentially hazardous asteroids.
April 2008 Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2008 FH5
Apr. 2
7.6 LD
20
17 m
2001 QO142
Apr. 6
34 LD
17
685 m
2008 GF1
Apr. 7
0.8 LD
18
10 m
2005 BE2
Apr. 10
62 LD
18
1.0 km
2005 NB7
Apr. 17
16 LD
16
705 m
2008 FU6
Apr. 22
62 LD
16
1.4 km
2005 TB
Apr. 28
47 LD
18
1.3 km
2001 DQ8
Apr. 30
74 LD
17
1.1 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 Links
NOAA Space Weather Prediction Center
  The official U.S. government bureau for real-time monitoring of solar and geophysical events, research in solar-terrestrial physics, and forecasting solar and geophysical disturbances.
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  From the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
  more links...
©2008, SpaceWeather.com -- This site is penned daily by Dr. Tony Phillips.
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