You are viewing the page for Apr. 18, 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: 413.2 km/s
density:
0.7 protons/cm3
explanation | more data
Updated: Today at 2246 UT


X-ray Solar Flares

6-hr max:
A2 1915 UT Apr18
24-hr: A3 0835 UT Apr18
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 18 Apr '06

Decaying sunspot 871 poses no threat for strong solar flares. Credit: SOHO/MDI.


Sunspot Number: 48
What is the sunspot number?
Updated: 17 Apr 2006

Far Side of the Sun

This holographic image reveals two sunspot groups on the far side of the sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
Btotal: 2.4 nT
Bz:
0.5 nT south
explanation | more data
Updated: Today at 2247 UT

Coronal Holes:

A gust of solar wind originating from the indicated coronal hole could hit Earth on April 20th. 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 2006 Apr 18 2204 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 2006 Apr 18 2204 UTC
Mid-latitudes
0-24 hr 24-48 hr
ACTIVE 15 % 15 %
MINOR 01 % 01 %
SEVERE 01 % 01 %

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

What's Up in Space -- 18 Apr 2006
Subscribe to Space Weather News

Did you sleep through the auroras of April? Next time get a wake-up call. Sign up for Spaceweather PHONE.

SUNSPOT WATCH: Solar activity comes in many forms. Decaying sunspot 871 poses no threat for strong solar flares--but it has produced a burst of poetry. "A nearly-blank sun still has something to say," points out astrophotographer and contributing poet Howard Eskildsen of Port Charlotte, Florida.

VENUS & URANUS: This morning, Venus and Uranus had a rare close encounter in the dawn sky. " It was amazing to see these two very different worlds together in the same eyepiece," says Mariano Ribas of Buenos Aires, Argentina. (continued below)

"Venus and Uranus were only 0.3 degrees apart when I took this picture today at 6:13 am local time from my observatory in Buenos Aires," he explains. "I held a digital camera in front of the eyepiece of my 120 mm (4.5 inch) reflector telescope."

LUNAR TRANSIT: When the Moon rose over Athens, Greece, on the evening of April 14th, photographer Anthony Ayiomamitis was ready. With a rapid-fire series of exposures, he caught an unusual event--the International Space Station (ISS) passing directly in front of the Moon:

Not visible in Ayiomamitis's 9-photo composite is a Progress supply rocket flying just ahead of the ISS. "The rising moon was only 20 degrees in altitude," he explains. "The Progress was not visible due to poor seeing at that altitude." The silhouette of the massive space station, however, was dark and striking as it flitted by the Sea of Tranquillity, crossing the entire lunar disk in only 0.85 seconds. Ayiomamitis has also accomplished this challenging trick with the Sun.

Space station flyby alerts: SpaceWeather PHONE.



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 18 Apr 2006 there were 778 known Potentially
Hazardous Asteroids

April-May 2006 Earth-asteroid encounters
ASTEROID

 DATE
(UT)

MISS DISTANCE

MAG.

 SIZE
(meters)
2000 PN9

March 6

7.9 LD

12

~2 km
2006 EH1

March 7

2.0 LD

18

~20 m
2006 EC

March 8

0.7 LD

16

~19 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

Daily images from the sun -- from the Big Bear Solar Observatory

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

You are visitor number 33875809 since January 2000.
©2019 Spaceweather.com. All rights reserved.