NASA's Meteoroid Environment Office has upgraded its estimates of a major fireball that exploded over the southeastern USA around 2:30 AM on August 28th. Lead researcher Bill Cooke says "the fireball reached a peak apparent magnitude of -16, about 20 times brighter than a Full Moon, and cast shadows on the ground. This indicates that the meteoroid had a mass of more than 110 kg (240 lbs) and was up to a meter in diameter. It hit the top of Earth's atmosphere traveling 25 km/s (56,000 mph)." (see movie in previous entry, below)

"This is the brightest event our network has observed in 5 years of operation," he continues. "There are reports of sonic booms reaching the ground, and data from 4 doppler radars indicate that some meteorites may have fallen along the fireball's ground track." (Note: The city in the ground track map is Cleveland, Tennessee, not Cleveland, Ohio.)

An initial calculation of the fireball's orbit suggested it might be a fragment from a Jupiter family comet. Improved estimates of the orbital parameters point to a different kind of object: a main belt asteroid. If meteorites are recovered from the Tennessee countryside, their chemical composition will tell researchers more about the origin of the fireball.
www.spaceweather.com

QUIET SUNSPOTS, ACTIVE FILAMENT: None of the sunspots on the Earthside of the sun is actively flaring. Technically, this means solar activity is "low." Nevertheless, a large magnetic filament in the sun's southern hemisphere erupted during the early hours of August 29th: movie. The CME it hurled into space might have an Earth-directed component. Stay tuned for updates.

MAJOR FIREBALL EVENT: Bill Cooke of NASA Meteoroid Environment Office reports that a major fireball event occurred over the southeastern USA on August 28th. The explosion was brighter than the Moon and it might have scattered meteorites on the ground. Watch the movie (on www.spaceweather.com), then read Cooke's full report below:

"On August 28 at 07:27 UTC (2:27 AM local time in Alabama), all six NASA all-sky cameras in the southeast picked up a very bright fireball," he says. "Its peak magnitude was approximately -11, or six times brighter than the Last Quarter Moon. This may very well be the brightest event our network has observed in 5 years of operation."

"The cameras were completely saturated, necessitating a manual solution of the fireball's trajectory and orbit," he adds. Initial results indicate that the meteoroid massed 45 kg (roughly 0.3 to 0.4 meters in diameter) and hit the top of Earth's atmosphere traveling 23.7 km/s (53,000 mph).   Cooke is currently examining doppler radar records and other data to determine where the fall zone is located.
www.spaceweather.com

Peter Brown of the University of Western Ontario reports an ourburst of Daytime Craterid meteors on August 28th. "The Canadian Meteor Orbit Radar is detecting about 20 meteors per hour (ZHR)," he says. "This is the first time in five years this has happened."

The source of the shower is Comet Boattini (C/2007 W1). Because the comet's debris stream comes close to Earth, Jupiter and Saturn, it experiences gravitational perturbations which make the shower highly variable. Try listening to the Daytime Craterids on Space Weather Radio.
www.spaceweather.com

To the human eye, a nearby flash of lightning looks blindingly white. But have you ever wondered what colors might emerge if the flash were spread out chromatically, like a rainbow? During a recent thunderstorm in Tarn, France, David Antao decided to find out. "I am an enthusiastic astro-spectroscopist," he says, "so I couldn't resist shooting some spectra." Here is the result:

"I found it really beautiful!" says Antao.

All of the colors of a rainbow are present in the lightning strike, but some colors are stronger than others. Red, green and blue emission lines zig-zag across the spectrum tracing the shape of the original bolt. These colors are mainly due to the recombination of electrons with nitrogen molecules broken apart and ionized by the searing heat of the lightning discharge. Lines from oxygen, hydrogen, and nitrogen oxides are present, too.

"By analysing this spectra, it is possible to determine the temprature of the lightning," notes Antao. "I am trying to do this now."
www.spaceweather.com

August 20, 2013 – ATLANTIC - Previously, oceanographers thought the Atlantic Ocean seafloor didn’t spit out as much iron as other regions. However, a recently discovered plume of iron billowing from the depth of the Atlantic Ocean suggests the seafloor may be pumping iron like a young Arnold Schwarzenegger. The oceanic iron cloud spreads for more than 1,000 kilometers (621 miles) across the Atlantic from west of Angola, Africa, to northeast of Rio de Janeiro, Brazil.

The iron-rich waters flow 1,500 to 3,500 meters (4,921 – 11,482 feet) beneath the surface of the ocean. The complete extent and shape of the iron plume remains to be discovered. “We had never seen anything like it,” said Mak Saito, Woods Hole Oceanographic Institute scientist and lead author of the study, in a press release. “We were sort of shocked—there’s this huge bull’s-eye right in the middle of the South Atlantic Ocean. We didn’t quite know what to do with it, because it went contrary to a lot of our expectations.”

Cracks in the Earth crust, or hydrothermal vents, on the ocean floor released the iron. However, the type of vent came as a surprise to the Woods Hole Oceanographic Institute and University of Liverpool oceanographers who discovered it. A long ridge splits the Atlantic Ocean as geological forces gradually force the ocean wider. The slow-spreading Atlantic ridge was thought to produce less iron and other chemicals than vents in regions with speedier splits, like the ridge in the eastern Pacific. “This study and other studies like it are going to force the scientific community to reevaluate how much iron is really being contributed by hydrothermal vents and to increase those estimates, and that has implications for not only iron geochemistry but a number of other disciplines as well,” said Saito.

The Atlantic Ocean iron plume may provide a smorgasbord for oceanic phytoplankton, the tiny, plant-like organisms that form the base of many marine food webs. Those phytoplankton provide food for fish and whales. The plankton also suck in large amounts of carbon dioxide. When the plankton die they can carry that carbon with them to bottom of the ocean.
–Discovery News
http://theextinctionprotocol.wordpress.com/2013/08/20/atlantic-ocean-floor-oozing-massive-iron-cloud-plume/

ANOTHER CME IS ON THE WAY: As Earth passes through the wake of one CME, which did little to stir geomagnetic activity on Aug. 20th, another CME is on the way. NOAA forecasters expect a coronal mass ejection hurled into space yesterday by an erupting magnetic filament to deliver a glancing blow to Earth's magnetic field on Aug. 23rd. High-latitude sky watchers should be alert for auroras.

SUNDIVING COMET AND FULL-HALO CME: A small comet plunged into the sun on August 20th. Just before it arrived, the sun expelled a magnificent full-halo CME. Click here to view a movie from the Solar and Heliospheric Observatory (SOHO):

In the final frames of the movie, the comet can be seen furiously vaporizing. Indeed, those were the comet's final frames. It did not emerge again from its flyby of the hot sun. "With a diameter of perhaps a few tens of meters, this comet was clearly far too small to survive the intense bombardment of solar radiation," comments Karl Battams of the Naval Research Lab, who studies sungrazing comets.

The CME (coronal mass ejection) came from an explosion on the farside of the sun. Although the CME and the comet appear to intersect, there was probably no interaction between the two. The comet is in the foreground and the farside CME is behind it.

Occasionally, readers ask if sundiving comets can trigger solar explosions. There's no known mechanism for comets to spark solar flares. Comets are thought to be too small and fragile to destabilize the sun's magnetic field. Plus, this comet was still millions of kilometers from the sun when the explosion unfolded.

The comet, R.I.P., was a member of the Kreutz family. Kreutz sungrazers are fragments from the breakup of a single giant comet many centuries ago. They get their name from 19th century German astronomer Heinrich Kreutz, who studied them in detail. Several Kreutz fragments pass by the sun and disintegrate every day. Most, measuring less than a few meters across, are too small to see, but occasionally a bigger fragment like this one attracts attention.
www.spaceweather.com

UPDATE 17/08/2013: BRIGHT NOVA: Nova Delphini, which exploded just three days ago in the northern constellation Delphinus, has continued to brighten. With a magnitude of +4.5, it is now easily visible in binoculars even from urban areas if you know where to look. This cactus in Tucson, Arizona, points the way:

"This is my obligatory southern-Arizona cactus photo of the nova in Delphinus," says photographer Scott Tucker. "It was actually visible to the naked eye at the time."

Novas occur in binary star systems when one star dumps matter onto a companion white dwarf. As the matter piles up on the surface of the white dwarf it heats up, fuses, and explodes, producing a flash of light 50,000 to 100,000 times brighter than the sun. Despite their brightness, most novas are invisible to the unaided eye because they are so far away. Nova Delphini is a rare exception.

A NEW STAR IN THE SKY : 16/08/2013 : Around the world, amateur astronomers are turning their telescopes toward minor constellation Delphinus where a new star has appeared. Koichi Itagaki of Yamagata, Japan, discovered the nova on August 14th. At the time, the stellar brightness was +6.3. Since then it has continued to brighten, crossing the 6th magnitude threshold of naked-eye visibility. John Chumack photographed the surging nova on August 15th from the John Bryan State Park in Yellow Springs, Ohio:

"The nova is hard to see naked eye unless you are in a very dark sky and know exactly where to look," says Chumack, "but this is a very bright nova visible in binoculars." He used a 16-inch Newtonian telescope to take the picture.

Backyard astronomers who wish to see this nova should point their GOTO telescopes to coordinates 20:23:30.7, +20:46:06 (J2000). More information and updates are available from Sky and Telescope.
www.spaceweather.com

COLORFUL SPRITES OVER NEBRASKA: "August 12th was another successful night in our sprites campaign," reports Jason Ahrns of the University of Alaska Fairbanks. With a team of researchers from NCAR, he has been flying over the midwestern USA onboard a Gulfstream V in search of exotic forms of lightning. As they were photographing a thunderstorm over Nebraska, these six sprites appeared:

These remarkably beautiful discharges were red on top and purple on the bottom. "I really can't explain the color change," says Ahrns. "That's one of the things we hope to investigate with this campaign by capturing high speed spectra."

First documented in 1989 by scientists from the University of Minnesota who photographed strange flashes coming out of the tops of thunderstorms, sprites remain a mystery today. Neither their basic physics nor their effect on the surrounding atmosphere is well understood. "Do sprites have a large scale impact on the middle atmosphere?" asks Ahrns. "Sprites clearly represent some kind of transfer of energy, but is it on a scale that has a significant effect on the weather and climate? We can't answer that without studying them."

The ephemeral nature of sprites (they typically last no more than a few milliseconds) makes them tricky to study. Researchers on the NCAR Gulfstream capture sprites using Phantom cameras running at 10,000 frames per second. "One of the Phantoms has a diffraction grating in front of it to capture high speed spectra, which I don't think has ever been done before," notes Ahrns.

The prettiest pictures, though, come from Arhns' own camera, a dSLR that he mounts in the window of the airplane to capture "beauty shots." The image above is an example.
www.spaceweather.com