You are viewing the page for Apr. 15, 2008
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 357.7 km/sec
density: 3.6 protons/cm3
explanation | more data
Updated: Today at 2246 UT
X-ray Solar Flares
6-hr max: A0
2220 UT Apr15
24-hr: A1
1305 UT Apr15
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 15 Apr 08
Yesterday's tiny sunspot has faded away leaving the sun once again blank. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 15 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= 2 quiet
24-hr max: Kp= 2
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 6.5 nT
Bz: 4.4 nT south
explanation | more data
Updated: Today at 2247 UT
Coronal Holes:
There are no well-organized coronal holes on the Earth-facing side of the sun. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2008 Apr 15 2203 UTC
0-24 hr
24-48 hr
01 %
01 %
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 15 2203 UTC
0-24 hr
24-48 hr
10 %
10 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
05 %
05 %
01 %
01 %
What's up in Space
April 15, 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

LOOKING FOR SATURN? It's right beside the Moon. Go outside tonight afer sunset and look around. The Moon is so big and bright, you won't even need a sky map to find it. See the golden "star" beside the Moon? That's Saturn. If you have a telescope, point it at Saturn and behold the planet's rings ... before they disappear.

SOLAR ACTIVITY: At its best and biggest a few days ago, tiny sunspot 990 was never much more than a speck on the surface of the sun, and now that speck is fading away. But regard this April 15th photo from Greg Piepol of Rockville, Maryland:

The decaying sunspot is the bright "splash" in the lower right. Piepol inserted an image of Earth for scale. It shows that on the mighty sun even measly decaying specks can be as big as planets. Everything is relative!

Sunspot 990 is only the second sunspot of new Solar Cycle 24. In the months ahead, new cycle spots will appear in greater size and number as solar activity emerges from its current low ebb and ascends toward the next Solar Maximum in 2011-2012; then the show will really begin. Stay tuned for solar activity.

LUNAR X: It's such a familiar sight, we often forget there's an alien world in our own backyard: the Moon. It's there tonight, almost full. Scan the Moon with an ordinary pair of binoculars or a small telescope and you will observe a fantastic landscape of lava seas, ancient craters, deep valleys and towering mountains.

And don't forget the Lunar X:

Amateur astronomer Dennis Fell of Wetaskiwin, Alberta, took this picture on April 12th. "It was an excellent night for binocular viewing," he says. "The 'X' was very pronounced."

Once a month when the sun rises over Crater Werner in the Moon's southern hemisphere, sunlight floods the region's high terrain and makes an X. The effect lasts only about two hours so careful timing and a little luck is required to catch it. "Observing the 'X' has little or no scientific value. It is a trick of the light. But the effect is striking, and it is exciting to rediscover each month," writes David Chapman in "A Fleeting Vision near Crater Werner" (Journal of the Royal Astronomical Society of Canada, Vol. 101, Issue 2, p.51).

The next viewing opportunity occurs May 12, 2008, around 1530 UT. Mark your calendar with an X.

more X-images: from Jeff Barton of Comanche Springs Astronomy Campus, Three Rivers Foundation for the Arts & Sciences, near Crowell, Texas; from Enrique Luque Cervigón of Alcalá de Henares, Madrid, Spain;

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

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 15, 2008 there were 947 potentially hazardous asteroids.
April 2008 Earth-asteroid encounters:
Miss Distance
2008 FH5
Apr. 2
7.6 LD
17 m
2001 QO142
Apr. 6
34 LD
685 m
2008 GF1
Apr. 7
0.8 LD
10 m
2005 BE2
Apr. 10
62 LD
1.0 km
2005 NB7
Apr. 17
16 LD
705 m
2008 FU6
Apr. 22
62 LD
1.4 km
2005 TB
Apr. 28
47 LD
1.3 km
2001 DQ8
Apr. 30
74 LD
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, -- This site is penned daily by Dr. Tony Phillips.
©2019 All rights reserved.