MAGNETIC STORM POSSIBLE THIS WEEK: 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
METEORS FROM HALLEY'S COMET: According to Canada's Meteor Orbit Radar (CMOR), a "hot spot" has appeared in the constellation Aquarius. This is a sign that the annual eta Aquarid meteor shower (ETA) is underway. This sky map shows where the radar is detecting pings from incoming meteors in broad daylight on May 2nd:
These meteors are pieces of Halley's Comet, hitting Earth's atmosphere at 66 km/s and disintegrating ~100 km above Earth's surface. In the days ahead our planet will cross a network of debris streams from the comet, producing a drizzle of eta Aquarids numbering 10 to 30 meteors per hour in the northern hemisphere and perhaps twice that number in the southern hemisphere.
Two leading meteor forecasters have noted the possibility of eta Aquarid outbursts. Mikhail Maslov says meteor activity could increase on May 4th (14h- 18h UT) when Earth grazes a dust trail released by Comet Halley in the year -616. Forecaster Mikiya Sato agrees that that Earth could encounter the -616 dust trail, but later on May 5th (05h - 15h UT), possibly with such a gentle graze that no special increase is detectable. In most years the strongest activity is seen around May 6th, which may still prove true in 2017.
The best time to look, no matter where you live, is during the dark hours just before dawn when the constellation Aquarius is rising in the east. Monitor the meteor gallery for sightings.
Realtime Space Weather Photo Gallery
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.
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.