MINOR MAGNETIC STORM POSSIBLE TODAY: A filament of magnetism on the sun exploded on April 30th, hurling a CME into space. NOAA analysts say the cloud could deliver a glancing blow to Earth's magnetic field on May 3rd with a 40% chance of minor geomagnetic storms following the impact. High-latitude sky watchers should be alert for auroras, especially in the southern hemisphere where darkening autumn skies favor visibility. Free: Aurora Alerts
HYPERBOLIC COMET JOHNSON: Discovered in November 2015 by Jess Johnson of the Catalina Sky Survey, Comet Johnson (C/2015 V2) is now swinging through the inner solar system on a hyperbolic orbit. A "hyperbolic orbit" means the sun's gravity will probably fling the comet into deep space later this year. Now is the time to look. Amateur astronomer Rolando Ligustri used a remotely controlled telescope in New Mexico to photograph the comet on May 1st:
Ligustri's 2 x 10 minute exposure with a 4-inch telescope reveals the comet's green nucleus and its double tail. The longer of the two is the filamentary ion tail, made of gas carried directly away from the sun by the solar wind. The shorter protuberance is the bright dust tail, made of dusty-rocky grains sprinkled like crumbs along the comet's orbit. Comet Johnson's nucleus is green because it contains diatomic carbon (C2) a substance that glows with a verdant hue in the near vacuum of space.
This comet is not visible to the naked eye, but as it approaches Earth for a 0.81 AU close encounter in early June, it is brightening to ~6th magnitude, making it an easy target for backyard telescopes. Northern hemisphere observers are favored in early May, when the comet dwells in the constellation Hercules; in late May and June, Comet Johnson races toward southern skies, where observers south of the equator can watch the comet continue its journey toward the sun. Resources: sky maps, 3D orbit, magnitudes.
DONALD DUCK MIRAGE: Sunset photographers witness many different kind of mirages as the solar disk sinks below the waves: the inferior mirage, the Etruscan vase mirage, the green flash. On May 2nd, Marcella Giulia Pace of Marina di Ragusa, Sicily, witnessed something new. Behold, the Donald Duck mirage:
"What can I say?" says Pace. "It looked like a duck!"
The technical name for this well-known apparition is "mock mirage." It occurs when one or more temperature inversion layers form above the water's surface. These layers cut the sun into horizontal slices, each slice stressed or compressed according to the refractive properties of the inversion layer. In this case, it turned the sun into a Disney character.
Sometimes, mock mirages end with a series of green and blue flashes. Read more about them here.
Realtime Space Weather Photo Gallery
THESE PENDANTS HAVE TOUCHED SPACE: These pendants have touched space--and returned to Earth in time for Mother's Day. To support their cosmic ray monitoring program, the students of Earth to Sky Calculus flew a payload-full of jewelry to the stratosphere onboard a high-altitude helium balloon. Here's one of the pendants 113,200 feet above the Sierras of central California:
These necklaces make great Mother's Day gifts--and you have have one for $89.95. Each glittering pendant comes with a greeting card showing the jewelry in flight and telling the story of its journey to the stratosphere and back again.
More far-out Mother's Day gifts may be found in the Earth to Sky Store. All proceeds support atmospheric radiation monitoring and hands-on STEM education.