SPACE WEATHER Current Conditions Solar Wind velocity: 634.0 km/s density:29.4 protons/cm3 explanation | more data Updated: Today at 2245 UT X-ray Solar Flares 6-hr max: C1 2055 UT Oct21 24-hr: M2 1135 UT Oct21 explanation | more data Updated: Today at 2245 UT Daily Sun: 21 Oct '01 Active region 9661 has decayed after unleashing two X-flares last Friday. It now exhibits a beta-gamma magnetic field that poses a threat for M-class flares. Image credit: SOHO/MDI The Far Side of the Sun This holographic image reveals no substantial sunspots on the far side of the Sun. Image credit: SOHO/MDI Sunspot Number: 230 More about sunspots Updated: 20 Oct 2001 Radio Meteor Rate 24 hr max: 73 per hr Listen to the Meteor Radar! Updated: 21 Oct 2001 Interplanetary Mag. Field Btotal: 25.9 nT Bz: 9 nT south explanation | more data Updated: Today at 2246 UT Coronal Holes: There are no substantial coronal holes on the Earth-facing side of the Sun. Image credit: Yohkoh Soft X-ray Telescope. More about coronal holes 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 2001 Oct 21 2200 UT FLARE | 0-24 hr | 24-48 hr | CLASS M | 75 % | 75 % | CLASS X | 15 % | 15 % | Geomagnetic Storms: Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm Updated at 2001 Oct 21 2200 UT Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 40 % | 40 % | MINOR | 40 % | 15 % | SEVERE | 15 % | 05 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 30 % | 50 % | MINOR | 50 % | 30 % | SEVERE | 20 % | 05 % | Web server provided by VPS Hosting | What's Up in Space -- 21 Oct 2001 Subscribe to Space Weather News! IMPACT: The first of two coronal mass ejections en route to Earth (see "Double Blast" below) swept past our planet on Oct 21st at 1645 UT. The interplanetary magnetic field turned sharply south when the disturbance arrived, setting the stage for a possible display of Northern Lights. Sky watchers located above geomagnetic latitude ~45 degrees should remain alert for auroras especially during the hours around local midnight. Above: NASA's ACE spacecraft registered a sudden increase in the solar wind speed just before a CME swept past Earth. METEOR WATCH: The annual Orionid meteor shower is active this weekend. Scientists at the NASA Marshall Space Flight Center recorded 18 visual meteors per hour between 0600 and 0830 UT on Oct. 21st -- a typical Orionid maximum. If you missed the show last night, try again tonight! The Orionid meteor shower has a broad maximum spread over several days. Sky watchers will likely spot 5-to-15 shooting stars per hour between 3 a.m. and dawn on Monday Oct 22nd. DOUBLE BLAST: Last Friday, twisted magnetic fields above sunspot 9661 erupted powerfully -- not once, but twice -- at 0105 UT and again at 1635 UT. Both explosions unleashed category X1.6 solar flares and hurled lopsided coronal mass ejections (CMEs) toward Earth. The first of the expanding clouds hit Earth's magnetosphere on Oct. 21st at 1650 UT; the second is still en route. Above: This SOHO cornagraph animation shows Friday's first halo CME. A second one billowed away from the Sun approximately 16 hours later. FLARE SOUNDS: Radio astronomer Thomas Ashcraft recorded a 29.5 MHz Type II radio burst from the second of the two Oct. 19th X-flares. Such bursts are the result of radio-emitting shock waves that plow through the solar corona. Listen: MP3. ZODIACAL LIGHTS: Autumn is the season for early morning Zodiacal Lights. Each day before dawn sky watchers with dark skies can spot a faint triangle of light above the eastern horizon caused by sunlight reflecting from interplanetary dust grains. Visit our Zodiacal Lights Gallery and see for yourself. WEB LINKS: NOAA FORECAST | GLOSSARY | SPACE WEATHER TUTORIAL | LESSON PLANS | BECOME A SUBSCRIBER | 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 are on a collision course with our planet, although astronomers are finding new ones all the time. On 21 Oct 2001 there were 335 known Potentially Hazardous Asteroids Oct. 2001 Earth-asteroid encountersNotes: 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. - PERSEIDS 2001: Perseid watchers on August 12th spotted meteors, auroras, and a disintegrating Russian rocket! [gallery]
- MORNING PLANETS: In July and Aug. 2001, the Moon, Jupiter, Saturn, Venus, and Mercury put on a dazzling early-morning sky show. [gallery]
- C/2001 A2 (LINEAR): This volatile comet is still visible through small telescopes as it recedes from Earth. [gallery]
- ECLIPSE SAFARI: Onlookers cried out in delight on June 21, 2001, when the Moon covered the African Sun, revealing the dazzling corona. [gallery]
- TOTAL LUNAR ECLIPSE: On Jan. 9, 2001, the full Moon glided through Earth's copper-colored shadow. [gallery]
- CHRISTMAS ECLIPSE: Sky watchers across North America enjoyed a partial solar eclipse on Christmas Day 2000 [gallery]
- LEONIDS 2000: Observers around the globe enjoyed three predicted episodes of shooting stars. [gallery]
July 27, 2001: Meteorites Don't Pop Corn -- A fireball that dazzled Americans on July 23rd probably didn't scorch any cornfields, contrary to widespread reports. June 12, 2001: The Biggest Explosions in the Solar System -- NASA's HESSI spacecraft aims to unravel an explosive mystery: the origin of solar flares. Feb. 21, 2001: Nature's Tiniest Space Junk -- Using an experimental radar, NASA scientists are monitoring tiny but hazardous meteoroids that swarm around our planet. Feb. 15, 2001: The Sun Does a Flip -- NASA scientists who monitor the Sun say our star's enormous magnetic field is reversing -- a sure sign that solar maximum is here. Jan. 25, 2001: Earth's Invisible Magnetic Tail -- NASA's IMAGE spacecraft, the first to enjoy a global view of the magnetosphere, spotted a curious plasma tail pointing from Earth toward the Sun. Jan. 4, 2001: Earth at Perihelion -- On January 4, 2001, our planet made its annual closest approach to the Sun. Dec. 29, 2000: Millennium Meteors -- North Americans will have a front-row seat for a brief but powerful meteor shower on January 3, 2001. Dec. 28, 2000: Galileo Looks for Auroras on Ganymede -- NASA's durable Galileo spacecraft flew above the solar system's largest moon this morning in search of extraterrestrial "Northern Lights" Dec. 22, 2000: Watching the Angry Sun -- Solar physicists are enjoying their best-ever look at a Solar Maximum thanks to NOAA and NASA satellites. MORE SPACE WEATHER HEADLINES |