THIRTEEN SUNSPOT GROUPS: Today there are thirteen sunspot groups on the Earthside of the sun--the greatest number so far in Solar Cycle 25. Despite the surfeit of sunspots, the sun has been quiet all weekend. Could it be the calm before the storm? One of the sunspots (AR3541) has a delta-class magnetic field that poses a threat for X-class solar flares. Solar flare alerts: SMS Text
BIRTH OF A CREPUSCULAR RAY: At one time or another, every sky watcher has seen a crepuscular ray--a long tube of darkness arcing across the twilight sky. It's a highlight of cloudy sunsets. Rarely, however, do onlookers see the source of the ray. This Saturday evening photo from Peter Lowenstein of Mutare, Zimbabwe, shows how they get started:
"The sunset was amazingly vivid and remained bright after the sun disappeared below the horizon," says Lowenstein. "The waning rays of the setting sun projected a prominent bright crepuscular ray upwards between an approaching cumulus cloud and the young (two-day-old) crescent Moon."
Lowenstein's photo shows what scientists have long known: Crepuscular rays are cloud shadows. The clouds themselves are usually too low on the horizion to see, so the rays appear to exist for no reason. Tall summertime cumulous clouds are usually to blame.
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VALENTINE'S CRYSTAL BEAR AND ROSE: Valentine's Day is coming. Looking for a far-out gift? This Crystal Bear and Rose flew to the stratosphere onboard a cosmic ray research balloon on Dec. 17th:
You can have it for $129.95. The students of Earth to Sky Calculus are selling space bears to support their high-altitude ballooning program. Each one comes with a greeting card showing the ursine astronaut in flight and telling the story of its journey to the edge of space and back again.
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All sales support hands-on STEM education
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