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

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Science news and information about the Sun-Earth environment.

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 316.2 km/s
density:
0.9 protons/cm3
explanation | more data
Updated: Today at 2245 UT

X-ray Solar Flares
6-hr max:
A0 2245 UT Apr16
24-hr: A0 0350 UT Apr16
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 16 Apr '07

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

Sunspot Number: 0
What is the sunspot number?
Updated: 15 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: 3.2 nT
Bz:
1.7 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 or about April 21st. 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 16 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 16 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 -- 16 Apr 2007
Subscribe to Space Weather News

Did you miss last night's auroras? Next time get a wake-up call from Spaceweather PHONE.

ASTEROID FLYBY: At 1 o'clock this morning, Universal Time, asteroid 2007 GU1 flew past Earth only 500,000 miles away. There was never any danger of a collision, but the flyby reminds us of another one that ended differently. In 1908, an asteroid about the same size as 2007 GU1 (approximately 50 meters wide) plunged to Earth over Russia's Stony Tunguska River; it exploded in mid-air, leveling 800 sq. miles of Siberian forest. Such an impact occurs every thousand years or so, researchers believe.

COMET LOVEJOY: Last night, Dennis Simmons of Brisbane, Australia, tried to photograph asteroid 2007 GU1 as it zipped past Earth, but finding the space rock too faint, he turned his attention to Comet Lovejoy (C/2007 E2). "I decided to grab some images as a consolation prize," he says. The result is this 2-hour movie:


Photo details: Vixen 102mm refractor,
SBIG ST7E CCD camera, 50 x 2 minutes

"Watching the fuzzy nucleus glide so eerily, effortlessly and silently past the fixed pattern of stars was quite mesmerizing, " he says. "Soon, two hours had been swallowed up by the night as dawn rushed in with birdsong and twilight bursting all around."

Comet Lovejoy is too faint to see with the unaided eye, but at 8th magnitude it is an easy target for backyard telescopes. Look for it in the constellation Aquila before dawn--just to the left of Jupiter. [sky map] [ephemeris]

PROMINENCE ALERT: Got a solar telescope? Point it at the sun. There's a beautiful prominence dancing over the northwestern limb, shown here in a 2-day movie from the Solar and Heliospheric Observatory (SOHO):


Solar activity, April 14-16, 2007. Credit: SOHO Extreme UV Telescope

Although the prominence looks like a flickering flame, it is not fire. Prominences are clouds of hydrogen held above the sun's surface by magnetic force fields. There's no combustion involved, as happens at the tip of a match. These clouds glow simply because they are hot--you would be too if you were so close to the surface of the sun!



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 16 Apr 2007 there were 857 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
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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