31
Mar
2014

April Fools’ Night aurora? / Wee crescent ‘smiles’ again in the west

If the aurora does show tomorrow night, it usually begins as a quiet, pale green arc like this one low in the northern sky. Often the arc will double and sprout rays if the display becomes more active. Credit: Bob King

This will probably turn out to be an April Fools’ joke, but space weather forecasters are predicting a 25% chance of minor aurora storms overnight April 1-2 when several particle blasts from the sun are expected to pound on Earth’s magnetic door.

That’s the forecast for skywatchers in mid-latitudes; polar folks will see a 60% chance of a major, sky-filling aurora. Be sure to check the skies starting tomorrow evening. The crescent moon sets early and won’t interfere with even the faintest auroras.

A very thin crescent moon appears low in the western sky this evening about a half hour after sunset. Stellarium

Speaking of the moon, you can watch a one-day-old crescent put on a smile starting about a half hour after sunset tonight March 31. Find a place with a wide-open view to the west northwest and look a short distance above the horizon a most delicate crust of moon.

We see the moon tipped on its back in spring because of the much steeper angle its path makes to the western horizon at dusk compared to fall. The planets, sun and moon all track on or near the same path called the ecliptic, which defines the plane of the solar system. Created with Stellarium

During northern hemisphere spring, the moon’s path across the sky makes a steep angle to the western horizon at dusk. That’s why it’s tipped over on its back and resembles a smile. In early fall, the crescent moon’s path intersects the evening horizon at a very shallow angle, tipping the moon upright on its southern cusp.

February’s crescent moon hovers over a snow-covered road. Credit: Bob King

Later this week, a thicker crescent moon will cross the Hyades star cluster, temporarily blocking up to three of its bright stars. Stay tuned – I’ll post a guide on how to watch it tomorrow.

8 Responses

  1. caralex

    God forbid any of the Nibiru crowd see the moon lying on its back! They’ll start another panic! “The moon is tilted!” Help!

  2. Profile photo of BCstargazer

    And lets not forget about the Zero G event from 4:01 to 4:20 pm…I’m sure space agencies are taking advantage of this as an opportunity for low-cost launch. For my part, this gives me a chance to practice my dodeca back flips routine 😉

          1. Profile photo of BCstargazer

            oh sure…once again, someone takes credit for my discoveries. them Coloradians think they have it all. Makes me think of the time I discovered the Frinkahedron only to have some then unknown Ernő Rubik rename it to take the fame and much needed research funding away…

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