Spaceweather.com Time Machine

You are viewing the page for Aug. 21, 2006

Select another date:

<<back

forward>>

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: 434.8 km/s
density: 2.2 protons/cm³
explanation | more data
Updated: Today at 2256 UT

X-ray Solar Flares
6-hr max: C4 1920 UT Aug21
24-hr: C4 1920 UT Aug21
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 21 Aug '06

Sunspot 904 is about to disappear over the sun's western limb. Meanwhile a new sunspot (labeled "?") is emerging in the east. Credit: SOHO/MDI

Sunspot Number: 15
What is the sunspot number?
Updated: 20 Aug 2006

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
B_total: 7.8 nT
B_z: 1.2 nT south
explanation | more data
Updated: Today at 2256 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole could reach Earth on August 21st or 22nd. Credit: NOAA GOES-13.

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 2006 Aug 21 2204 UTC

FLARE	0-24 hr	24-48 hr
CLASS M	10 %	10 %
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 2006 Aug 21 2204 UTC
Mid-latitudes

	0-24 hr	24-48 hr
ACTIVE	25 %	20 %
MINOR	05 %	05 %
SEVERE	01 %	01 %

High latitudes

	0-24 hr	24-48 hr
ACTIVE	30 %	25 %
MINOR	10 %	10 %
SEVERE	01 %	01 %

What's Up in Space -- 21 Aug 2006
Subscribe to Space Weather News

Did you miss the aurora surprise of August 7th? Next time get a wake-up call: Spaceweather PHONE.

PLANETS ALIGN: Set your alarm. If you wake up before dawn on Tuesday, Aug. 22nd, you can see three planets lined up with the crescent Moon. Just go outside and look east. It's a beautiful sight, and a nice way to begin the day: sky map.

AURORA BOREALIS: On Saturday night, Aug. 19th, spectacular auroras rippled across Scandinavia. It was the kind of display that could make you dash out of the sauna to grab your camera. Indeed, that's exactly what Markku Hirvenoja did. He dashed out and took this picture of the sky over Vojakkala, Finland:

What caused the display? Around mid-day on August 19th, the interplanetary magnetic field (IMF) tipped south, opening a crack in Earth's magnetic defenses. Solar wind poured in and fueled a geomagnetic storm.

August 2006 Aurora Gallery

DEPARTING SUNSPOT: Goodbye, and thanks for all the snapshots. Photogenic sunspot 904 is approaching the sun's western limb. Shortly, perhaps just hours from now, it will go over the edge and out of sight. Photographer Sylvain Weiller of St Rémy lès Chevreuse, France, took this parting shot on August 20th:

Good news: As 904 vanishes in the west, a new sunspot is emerging in the east. Will it be photogenic, too? Stay tuned.

more images: from Gary Palmer of Los Angeles, CA; from Eric Roel of Valle de Bravo, Mèxico; from Didier Favre of Brétigny sur Orge, France.

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 Aug 2006 there were 801 known Potentially
Hazardous Asteroids

August 2006 Earth-asteroid encounters

ASTEROID	DATE (UT)	MISS DISTANCE	MAG.	SIZE
2006 ON1	Aug 20	16.6 LD	18	230 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. See also Snow Crystals.

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 --a gallery of up-to-date solar pictures from the National Solar Data Analysis Center at the Goddard Space Flight Center. See also the GOES-12 Solar X-ray Imager.

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

SOHO Farside Images of the Sun from SWAN and MDI.

The Latest SOHO Coronagraph Images -- from the Naval Research Lab

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

Observable Comets -- from the Harvard Minor Planet Center.

What is the Interplanetary Magnetic Field? -- A lucid answer from the University of Michigan. See also the Anatomy of Earth's Magnetosphere.

Real-time Solar Wind Data -- from NASA's ACE spacecraft. How powerful are solar wind gusts? 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 1998 to 2001

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006;

Space Audio Streams: (University of Florida) 20 MHz radio emissions from Jupiter: #1, #2, #3, #4; (NASA/Marshall) INSPIRE: #1; (Stan Nelson of Roswell, New Mexico) meteor radar: #1, #2;

Recent International Astronomical Union Circulars

GLOSSARY | SPACE WEATHER TUTORIAL

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