EMERGING CME: A coronal mass ejection (CME) left the sun this morning, Oct. 5, and it could be heading for Earth. Orbiting at the L1 Lagrange point, the Solar and Heliosphere Observatory captured this image of the expanding cloud:
DRACONID METEOR SHOWER: The notoriously unpredictable Draconid meteor shower peaks this year on the night of Oct. 7-8. In most years, the Draconids come and go with a barely noticable peak of 10 or so meteors per hour. Occasionally, however, Earth passes through a dense clump of debris from parent comet 21P/Giacobini-Zinner and a meteor storm erupts. Just last year, Europeans witnessed a faint but furious outburst of 600 per hour. There is no reason to believe that 2012 is a "storm year." Nevertheless, northern hemisphere sky watchers are encouraged to be alert for slow-moving Draconids on Sunday night. EMERGING CME: A coronal mass ejection (CME) left the sun this morning, Oct. 5, and it could be heading for Earth. Orbiting at the L1 Lagrange point, the Solar and Heliosphere Observatory captured this image of the expanding cloud: The source of the cloud appears to be an eruption of magnetic fields connecting sunspots 1582 and 1579. This conclusion is preliminary, however, and may be revised later today when more data are available. For now it appears that the CME will deliver a glancing blow to Earth's magnetic field on Oct. 7-8. Stay tuned for updates. www.spaceweather.com
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PLANETS ALIGN THIS WEEKEND: The Moon, Venus, and Jupiter are lining up in the eastern sky this weekend--right in the middle of the Perseid meteor shower. It's a must-see event. A new ScienceCast video from NASA previews the display. PERSEID METEOR SHOWER: The annual Perseid meteor shower is underway. International observers are reporting 15+ meteors per hour in pre-dawn skies as Earth enters a broad stream of debris from parent comet Swift-Tuttle. The shower has been building since late July. Over the past two weeks, NASA's All-Sky Meteor Network has recorded more than 57 Perseid fireballs. Their orbits are shown here, with Earth's position marked in red: The show is about to get much better. Earth will pass through the heart of the debris stream on the nights of August 11th through 13th, boosting meteor rates beyond 100 per hour. Forecasters say the best time to look is probably during the dark hours before sunrise on Sunday, August 12th.
www.spaceweather.com A key ingredient of Earth's strangest clouds does not come from Earth. New data from NASA's AIM spacecraft shows that "meteor smoke" is essential to the formation of noctilucent clouds. [full story] MINOR GEOMAGNETIC STORM: A minor geomagnetic storm is underway. The cause is a knot of south-pointing magnetism drifting past Earth. The IMF is opening a crack in Earth's magnetosphere, allowing solar wind to enter and fuel the storm. CURIOSITY & SOLAR FLARES: Mars rover Curiosity has been hit by multiple solar flares en route to the Red Planet, giving NASA planners an idea of what faces human astronauts in the Earth-Mars expanse. [full story] PERSEID METEORS: 1 August 2012 : Earth has entered a broad stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Meteoroids in the outskirts of the stream are now hitting Earth's atmosphere, producing as many as 10-15 meteors per hour according to worldwide counts from the International Meteor Organization. NASA's network of all-sky meteor cameras captured 17 Perseid fireballs on the nights of July 28th through 30th. Here are their orbits: The position of Earth is denoted by the red starburst; all of the meteoroid orbits intersect at that point. The purple line traces the orbit of the parent Comet Swift-Tuttle. Fortunately, the comet itself does not intersect Earth. In the days ahead, Earth will plunge deeper into the meteoroid stream, and meteor rates will increase accordingly. Forecasters expect the shower to peak on August 12-13 with as many as 100+ meteors per hour visible from dark-sky sites. Monitor the realtime meteor gallery for sightings. 2 August 2012 : As Earth enters a broad stream of debris from Comet Swift-Tuttle, more and more Perseid meteors are appearing in the night sky. "Last night, I captured a Perseid fireball ripping through the ionosphere over New Mexico," reports amateur astronomer Thomas Ashcraft. "It was travelling pretty fast - 133,000 miles per hour!" Click to see and hear the meteoroid disintegrate: [go to www.spaceweather.com] The movie's sound track comes from Ashcraft's dual-frequency meteor radar. It works like this: Radio signals from distant VHF transmitters bounce off the meteor's ion trail. Ashcraft's antennas can pick up those reflections, which sound like ghostly echoes in the loudspeaker of his VHF receiver.
At the moment, Perseid meteor rates are low--no more than about 10 per hour. In the days ahead, however, Earth will plunge deeper into the comet's debris stream, and meteor activity will increase accordingly. Forecasters expect the shower to peak on August 12-13 with as many as 100+ meteors per hour visible from dark-sky sites. Stay tuned for Perseids. www.spaceweather.com GEOMAGNETIC STORM WARNING: NOAA forecasters estimate a 45% chance of polar geomagnetic storms on July 29-30 in response to a high-speed solar wind stream buffeting Earth's magnetic field. Even stronger storming could occur on July 31st when a CME associated with yesterday's M6-flare arrives. High-latitude sky watchers should be alert for auroras for the next three nights. SOLAR ACTIVITY PICKS UP: Sunspot AR1532 is crackling with M-class solar flares. The latest, an M6-class eruption on July 28th (2056 UT), produced a bright flash of extreme ultraviolet radiation, shown here in a snapshot from the Solar Dynamics Observatory: Contrary to earlier reports, this explosion did produce a CME and the cloud is heading for Earth. According to a forecast track prepared by analysts at the Goddard Space Weather Lab, the CME will reach our planet on July 31st at 1500 UT (+/- 7 hours). Weak to moderate geomagnetic storms are possible when the cloud arrives. METEOR ACTIVITY: During Friday night, NASA's All Sky Fireball Network detected 17 Venus-bright meteors. The orbits of the meteoroids, color-coded by velocity, are shown in the diagram below. Earth's location is marked by a red starburst: The green orbits correspond to Comet 96P/Machholz, source of the annual delta Aquarid meteor shower. Although this is a minor shower, it is fraught with interest. Some researchers believe that 96P/Machholz came from another star system. Every delta Aquarid that disintegrates in the night sky could be depositing material from across the galaxy into Earth's upper atmosphere.
Forecasters expect as many as 15 delta Aquarids per hour when the shower peaks on July 28th and 29th. The best time to look, no matter where you live, is during the dark hours before sunrise on Saturday and Sunday when the moon has set and the constellation Aquarius is relatively high in the sky. Blue orbits correspond mainly to Perseids. The Perseid meteor shower doesn't peak until August 12-13, but Earth is already in the outskirts of the debris zone of the parent comet, 109P/Swift-Tuttle. By mid-August, rates could exceed 100 meteors per hour. The show, in other words, is just getting started. www.spaceweather.com Periodic comet 96P/Maccholz is passing by the sun today deep inside the orbit of Mercury. At closest approach, the icy visitor from the outer solar system will be less than 12 million miles (0.13 AU) from the solar surface. Coronagraphs onboard the Solar and Heliospheric Observatory are monitoring the encounter: [go to: www.spaceweather.com] "Discovered in 1986, Comet 96P/Machholz is a fascinating comet that has passed through SOHO coronagraph images four times now," says Karl Battams of the Naval Research Lab. "It's not a huge comet but it is very photogenic, and puts on quite a display with its beautiful dusty tail."
In an essay posted on his web site, Battams explains why the comet is so fascinating. Many researchers suspect 96P/Machholz is not a native of our solar system; some chemical evidence suggests it came from another star. Also, 96P/Machholz appears to be dynamically related (that is, the comet's orbit is related) to a diverse collection of other objects in the solar system including asteroid 2003 EH1 and the Quadrantid, Southern Delta Aquariid, and daytime Arietid meteoroid streams. All of these things--the asteroid, the comet, and the meteoroids--might be fragments of a single "foreign" body that broke apart thousands of years ago. Comet 96P/Machholz will be visible in SOHO coronagraphs until July 17th. Battams believes the comet will reach a peak brightness of 2nd magnitude--not its best show. "But who knows," he says, "maybe Comet Machholz will do something completely and utterly unexpected like fragment into a swarm of Machholzlets." Join SOHO for a ringside seat. www.spaceweather.com The eta Aquarid meteor shower, due to peak on May 5-6, is already underway. Cameras in NASA's All-Sky Fireball Network have picked up more than a dozen eta-fireballs this week, including seven last night alone. NASA astronomer Bill Cooke prepared this diagram showing the orbits of the fireballs detected so far:
Earth is entering a stream of debris from Halley’s Comet, source of the annual eta Aquarid meteor shower. Because the shower’s radiant is located below the celestial equator, southern hemisphere observers are favored, but even northerners will be able to see at least a few flecks of Halley-dust disintegrating in the atmosphere when the shower peaks this weekend.
The best time to look is during the hours before sunrise on Sunday, May 6th. Bright moonlight will cap the meteor rate at about 30 per hour. In recent nights, NASA’s all-sky meteor network has picked up a number of early eta Aquarid fireballs. www.spaceweather.com On Sunday morning, April 22nd, just as the Lyrid meteor shower was dying down, a spectacular fireball exploded over California's Sierra Nevada mountain range. The loud explosion rattled homes from central California to Reno, Nevada, and beyond. According to Bill Cooke, head of NASA's Meteoroid Environment Office, the source of the blast was a meteoroid about the size of a minivan. "Elizabeth Silber at Western University has searched for infrasound signals from the explosion." says Cooke. "Infrasound is very low frequency sound which can travel great distances. There were strong signals at 2 stations, enabling a triangulation of the energy source at 37.6N, 120.5W. This is marked by a yellow flag in the map below."
Assuming this value for the speed, I get a mass for the meteor of around 70 metric tons. Hazarding a further guess at the density of 3 grams per cubic centimeter (solid rock), I calculate a size of about 3-4 meters, or about the size of a minivan."
"This meteor was probably not a Lyrid; without a trajectory I cannot rule out a Lyrid origin, but I think it likely that it was a background or sporadic meteor." www.spaceweather.com
Grampian Police said reports of people seeing a “flare or a bright object with a tail” were received from across the region. And Dumfries and Galloway Constabulary said numerous calls were made about a “large ball of fire in the sky” across Annandale and Eskdale. One user wrote on the force’s Facebook page: “It was awesome to see! Really big and bright!” Hundreds of people took to Twitter to report similar sightings across Scotland and the north of England. People described seeing a bright fireball moving across the sky with a large tail. The Kielder Observatory also reported the sighting of a “huge fireball” travelling from north to south over Northumberland at 9.41pm. The Observatory posted on Twitter: “Of 30 years observing the sky, this fireball is the best thing I have ever seen period.” –Telegraph
http://theextinctionprotocol.wordpress.com/ Feb. 22, 2012: In the middle of the night on February 13th, something disturbed the animal population of rural Portal, Georgia. Cows started mooing anxiously and local dogs howled at the sky. The cause of the commotion was a rock from space. "At 1:43 AM Eastern, I witnessed an amazing fireball," reports Portal resident Henry Strickland. "It was very large and lit up half the sky as it fragmented. The event set dogs barking and upset cattle, which began to make excited sounds. I regret I didn't have a camera; it lasted nearly 6 seconds." Strickland witnessed one of the unusual "Fireballs of February." A fireball over north Georgia recorded on Feb. 13th by a NASA all-sky camera in Walker Co., GA. (video) "This month, some big space rocks have been hitting Earth's atmosphere," says Bill Cooke of NASA's Meteoroid Environment Office. "There have been five or six notable fireballs that might have dropped meteorites around the United States." It’s not the number of fireballs that has researchers puzzled. So far, fireball counts in February 2012 are about normal. Instead, it's the appearance and trajectory of the fireballs that sets them apart. "These fireballs are particularly slow and penetrating," explains meteor expert Peter Brown, a physics professor at the University of Western Ontario. "They hit the top of the atmosphere moving slower than 15 km/s, decelerate rapidly, and make it to within 50 km of Earth’s surface." To read the whole article/watch video: http://science.nasa.gov/science-news/science-at-nasa/2012/22feb_februaryfireballs/ |
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