ION WAVES IN EARTH'S ATMOSPHERE: Today, a volley of C-class solar flares sent waves of ionization rippling through the atmosphere high over Europe. Dave Gradwell of Birr, Ireland, detected the disturbances using a VLF radio monitoring system:

The source of the flares is a sunspot in the sun's southern hemisphere (tentatively numbered AR1463)--one of several active regions popping up around the solar disk. With sunspot numbers on the rise, more flares and ion waves are likely in the days ahead.

INCOMING PLASMA CLOUDS: On April 18th and 19th, a series of minor CMEs puffed away from the sun. Three of them are heading in our general direction. Analysts at the Goddard Space Weather Lab have prepared an animated forecast track of the ensemble:

According to the forecast, the clouds are going to hit Mercury, Earth, Mars and rover Curiosity en route to Mars. The impact on our planet, on April 22nd around 00:50 UT, is expected to be minor with auroras likely only at higher latitudes.

GEOMAGNETIC STORM: A minor (Kp=5) geomagnetic storm is underway. This is probably due to Earth's passage through the wake of a CME that swept past our planet earlier today. Solar wind speed: 359.6 km/sec

SIERRA FIREBALL DECODED: 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 Envronment Office, the source of the blast was a meteoroid about the size of a minivan. "The energy is estimated at a whopping 3.8 kilotons of TNT, so this was a big event," he continues. "I am not saying there was a 3.8 kiloton explosion on the ground in California. I am saying that the meteor possessed this amount of energy before it broke apart in the atmosphere. [The map] shows the location of the atmospheric breakup, not impact with the ground."

"The fact that sonic booms were heard indicates that this meteor penetrated very low in atmosphere, which implies a speed less than 15 km/s (33,500 mph). "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."

April 23, 2012 – SPACE - Here’s troubling news in the world of astrophysics, in which astronomers can’t seem to find the dark matter. As you may know dark matter is a much-speculated upon, but unknown substance that cannot be seen but appears to exist as it exerts a gravitational force on material around it. Astronomers first posited the existence of dark matter to explain why the outer portions of galaxies rotate quickly, and it now is also an important part of theories that explain how galaxies form and grow. Scientists believe there must be about five times as much dark matter in the universe as normal matter — atoms, planets, you and me. Last week, in a study that didn’t get the attention it probably deserves, astronomers said they could find any dark matter near our Sun. Existing theories predict that the average amount of dark matter in the Sun’s part of the galaxy should be in the range 1 to 2 pounds of dark matter in a volume the size of the Earth. The new measurements found nada. Zip. Zilch.“This is an article that we are going to have to take seriously,” Texas A&M astronomer Nick Suntzeff told me. Which is to say that if dark matter is not where our theories predict it will be, our theories probably have some serious issues. –Chron




Mystery of cosmic rays deepens: The mystery of the origin of the strongest cosmic rays has deepened as new clues into key suspects, the most powerful explosions in the universe, suggest they are likely not potential culprits, researchers say. Gamma-ray bursts are the most powerful explosions in the universe. They can emit as much energy as our sun during its entire 10-billion-year lifetime in anywhere from milliseconds to minutes. Some gamma-ray bursts are thought to be collapses of super massive stars — hypernovas — while others are thought to be collisions of black holes with other black holes or neutron stars,” said study co-author Spencer Klein of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory. “Both types produce brief but intense blasts of radiation.” New evidence may now rule out gamma-ray bursts as sources of these. Using the IceCube Neutrino Observatory at the South Pole in Antarctica, the boffins watched 300 gamma ray bursts (GRBs) while searching for the neutrinos that are believed to be linked with cosmic ray generation, and found none. “The unexpected absence of neutrinos from GRBs has forced a re-evaluation of the theory for production of cosmic rays and neutrinos in a GRB fireball and possibly the theory that high energy cosmic rays are generated in fireballs.” -Space, Register

CHANCE OF FLARES: Sunspot AR1465 has developed a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares. Because of the sunspot's location near the middle of the solar disk, any eruptions will likely be Earth-directed. Solar wind speed: 650.8 km/se

QUIETING STORM, MORE TO COME: Earth's magnetic field is quieting after two straight nights of mild to moderate geomagnetic storms. At the height of the disturbance on April 23-24, auroras were spotted in more than a dozen US states including Michigan, Nebraska, Kansas, Wisconsin, North Dakota, South Dakota, Iowa, Illinois, Minnesota, and Colorado. On the threshold of the Arctic Circle in Anchorage, Alaska, the Northern Lights pierced the glow of the midnight sun: More auroras may be in the offing. A minor CME is en route to Earth, due to arrive on April 26th. NOAA forecasters estimate a 20% to 30% chance of geomagnetic storms.

FARSIDE ACTIVITY: For more than a week, solar activity has been low. On April 26th around 0600 UT, an active region on the farside of the sun broke the calm with a powerful eruption. NASA's Solar Dynamics Observatory recorded a massive cloud of plasma flying over the sun's southwestern limb: The same active region has since hurled three CMEs into space. The clouds will certainly miss Earth, but they might hit Mercury, which appears to be in the line of fire.

CHANCE OF FLARES: Sunspot AR1465 has developed a 'beta-gamma-delta' magnetic field that harbors energy for strong flares. NOAA forecasters estimate a 20% chance of M-class eruptions during the next 24 hours. Because the active region is located on the Earthside of the sun, any flares from AR1465 will likely be geoeffective.

Even without a strong eruption from AR1465, ionization waves are already rippling through Earth's upper atmosphere. Dave Gradwell of Birr, Ireland, recorded a series of sudden ionospheric disturbances (SIDs) on April 27th:


Low-level flares from several sunspot groups (especially 1465, 1466 and 1467) are strobing the atmosphere with ionizing radiation. Using a VLF receiver, Gradwell detected their effect on the propagation of radio signals transmitted from France. So far the disturbances have been relatively weak, but this could change if AR1465 unleashes a more potent eruption over the weekend.

MARS-DIRECTED CME: A minor CME that left the sun during the late hours of April 28th is heading for Mars. En route, it will sweep past the Mars Science Lab spacecraft, which is carrying Curiosity to the Red Planet. According to a forecast track prepared by analysts at the GSFC, the cloud will reach the rover on May 4th.

SUNSPOT MIRAGE: When the sun rose over Veszprem Hungary on May 1st, big sunspot AR1471 split into three pieces. "It was a mirage--the strongest I have ever seen!" says Monika Landy-Gyebnar, who photographed the apparition:

Landy-Gyebnar explains how she arranged the photo-op: "We had a nice, clear and windless morning. I set up my camera where I could see the sun rising over a cold valley where fog often collects; it is a location colder then its surroundings. I hoped the inversion layer at the valley would provide some distortion--and indeed it did. The image I saw when sun appeared was incredible!"

METEORS FROM HALLEY'S COMET: Earth is entering a stream of debris from Halley's Comet, source of the annual eta Aquarid meteor shower. The shower peaks this weekend; the best time to look is during the hours before sunrise on Sunday, May 6th. Because the shower's radiant is located below the celestial equator, southern hemisphere observers are favored, but even northerners should be able to see a few flecks of Halley-dust disintegrating in the atmosphere. Super-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. This one was bright enough to shine through the glow of sunrise and clouds over Tullahoma, Tennessee, on April 29th: According to analysts at NASA's Meteoroid Environment Office, this particular speck of comet dust hit the atmosphere traveling 62 km/s (139,000 mph) and disintegrated about 84 km (52 mi) above Earth's surface.

The full Moon of May 5-6, 2012, with interfere with the visibility of the eta Aquarid peak. Radar signals, however, penetrate moonlight with ease. Tune into Space Weather Radio for live echoes from eta Aquarids passing over the US Air Force Space Surveillance Radar in Texas.

BIG NEW SUNSPOT: A large sunspot group is rotating into view over the sun's northeastern limb. The emergence of this apparently significant active region could herald an increase in solar activity. Solar flare alerts: text, phone.

"SUPER MOON" TONIGHT: Tonight's full Moon is a perigee moon, as much as 14% bigger and 30% brighter than other full moons of 2012. This is a harmless but beautiful astronomical phenomenon. Enjoy the moonlight! [video] [full story] [Moonshots: #1, #2, #3, #4, #5]

METEORS FROM HALLEY'S COMET: The eta Aquarid meteor shower is peaking today as Earth passes through a stream of debris from Halley's Comet. Unfortunately, bright moonlight is washing out all of the faint meteors, but some eta Aquarids are piercing the glare. Last night, NASA's network of all-sky fireball cameras recorded eight fireballs, including this one exploding over New Mexico: www.spaceweather.com

BIG SUNSPOT: One of the largest sunspot groups in years rotated over the sun's northeastern limb this weekend. With a least four dark cores larger than Earth, AR1476 sprawls more than 100,000 km from end to end, and makes an easy target for backyard solar telescopes. Amateur astronomer Alan Friedman sends this picture of the behemoth from his backyard in Buffalo, NY: "AR1476 is firecrackler," says Friedman.

Indeed, the active region is crackling with impulsive M-class solar flares. Based on the sunspot's complex 'beta-gamma' magnetic field, NOAA forecasters estimate a 70% chance of more M-flares during the next 24 hours. There is also a 5% chance of powerful X-flares.

CHANCE OF FLARES: Huge sunspot AR1476 is crackling with M-class solar flares and appears to be on the verge of producing even stronger blasts. The sunspot's 'beta-gamma-delta' magnetic field harbors energy for X-class flares, the most powerful kind. Eruptions in the days ahead will likely be geoeffective as the sunspot turns to face Earth. A pair of CMEs en route to Earth could add to the effect of the solar wind stream, igniting even brighter auroras during the next 24-48 hours. NOAA forecasters estimate a 40% chance of geomagnetic storms on May 9th.

Large sunspot 1476 produced a moderate M4.7 solar flare at 12:32 UTC on May 9, 2012. This video includes images and movies by EVE and SDO. May 9, 2012 – SOLAR ACTIVITY INTENSIFIES: Huge sunspot AR1476 is crackling with M-class solar flares and appears to be on the verge of producing something even stronger. The sunspot’s ‘beta-gamma-delta’ magnetic field harbors energy for X-class flares, the most powerful kind. Earth is entering the line of fire as the sunspot rotates across the face of the Sun. –Space Weather