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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

SpaceWeather.com
Science news and information about the Sun-Earth environment.

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 289.2 km/s
density:
5.6 protons/cm3
explanation | more data
Updated: Today at 2245 UT

X-ray Solar Flares
6-hr max:
A0 2245 UT Apr21
24-hr: A0 2245 UT Apr21
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 21 Apr '07

The sun is blank--no sunspots. Credit: SOHO/MDI


Sunspot Number: 0
What is the sunspot number?
Updated: 20 Apr 2007

Far Side of the Sun

This holographic image reveals no sunspots on the far side of the sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
Btotal: 3.4 nT
Bz:
1.4 nT north
explanation | more data
Updated: Today at 2246 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole should reach Earth on April 21st or 22nd. Credit: SOHO Extreme UV telescope


SPACE WEATHER
NOAA
Forecasts

Solar Flares: Probabilities for a medium-sized (M-class) or a major (X-class) solar flare during the next 24/48 hours are tabulated below.
Updated at 2007 Apr 21 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 2007 Apr 21 2203 UTC
Mid-latitudes
0-24 hr 24-48 hr
ACTIVE 25 % 20 %
MINOR 10 % 10 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 35 % 25 %
MINOR 20 % 15 %
SEVERE 05 % 01 %

What's Up in Space -- 21 Apr 2007
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What's the name of that star? Where's Saturn? Get the answers from mySKY--a fun new astronomy helper from Meade.

3D SUN: On Monday, April 23rd, NASA will release, for the first time, 3-dimensional photos of the sun taken by the STEREO spacecraft. Magnetic loops and prominences will practically leap out of your computer screen. These images will be displayed on big screens at museums and science centers around the USA (list) and posted on the internet. Get ready this weekend by buying or building some 3D glasses--and stay tuned for Monday!

AURORA WATCH: A solar wind stream is heading for Earth and it could cause a geomagnetic storm when it arrives on April 21st or 22nd. Sky watchers from Scandinavia to Alaska should be alert for auroras.

Advice: Can't see any auroras? Use your camera. Auroras too faint for the unaided eye often show up beautifully in a exposure of only 10 seconds or so. Pictured above are some "photographic auroras" recorded April 17th by Tony Wilder of Chippewa Falls, Wisconsin, on April 17th. "I used a Canon 30D set to ISO 1000," he says.

WEEKEND METEORS: Earth is entering the dusty tail of Comet Thatcher, and this will cause a mild meteor shower this weekend. It's called the Lyrid meteor shower because the bits of incandescent comet dust appear to come from the constellation Lyra. The best time to look is during the dark hours before dawn on Sunday, April 22nd, and Monday, April 23rd, when you can expect to see a shooting star overhead every 5 minutes or so: sky map.

Meanwhile on the Moon: There's going to be a meteor shower on the Moon, too, but unlike Earth the Moon has no atmosphere to intercept Lyrids. Instead, meteoroids will hit the lunar surface and explode. This diagram shows how Lyrids will rain down over the north pole of the crescent Moon:


Credit: Bill Cooke, NASA Meteoroid Environment Office, MSFC

Using a Meade 14-inch telescope, astronomers at NASA's Marshall Space Flight Center have shown that lunar meteors are sometimes observable from Earth. They appear as brief flashes of light ranging in brightness from 3rd to 8th magnitude. If you're up for a challenge, train your telescope on the dark side of the crescent Moon this weekend; you might catch an exploding Lyrid.

Lunar Meteors Home Page
[minimum system requirements]



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 21 Apr 2007 there were 858 known Potentially
Hazardous Asteroids

April 2007 Earth-asteroid encounters
ASTEROID

 DATE
(UT)

MISS DISTANCE

MAG.

 SIZE
2006 VV2

Mar. 31

8.8 LD

10

2 km
2007 FY20

Apr. 2

5.3 LD

19

50 m
2007 DS84

Apr. 14

16 LD

15

325 m
2007 GU1

Apr. 16

2.1 LD

16

45 m
2007 HA

Apr. 17

6.5 LD

13

300 m
Notes: LD is a "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 Environment 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. (European Mirror Site)

Daily Sunspot Summaries -- from the NOAA Space Environment Center.

Current Solar Images -- from the National Solar Data Analysis Center

Recent Solar Events -- a summary of current solar conditions from lmsal.com.

What is the Magnetosphere?

The Lion Roars -- visit this site to find out what the magnetosphere sounds like.

List of Potentially Hazardous Asteroids -- from the Harvard Minor Planet Center.

Observable Comets -- from the Harvard Minor Planet Center.

Real-time Solar Wind Data -- from NASA's ACE spacecraft.

How powerful are solar wind gusts? Not very! Read this story from Science@NASA.

More Real-time Solar Wind Data -- from the Solar and Heliospheric Observatory Proton Monitor.

Lists of Coronal Mass Ejections -- from 1996 to 2006

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1994, 1995, 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006; Apr-Jun 2006; Jul-Sep 2006; Oct-Dec 2006.

This site is penned daily by Dr. Tony Phillips: email


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