Jupiter, Ganymede, Europa and double shadows, March 25, 2019

Celestial Objects to Observe

Watch Jupiter's Moons in Unusual Lineups

You'll have five opportunities in the coming months to see Jupiter's moons in interesting alignments.

Don Machholz

People, Places, and Events

Remembering Donald Machholz, 1952 - 2022

Sky & Telescope honors the life of Donald Machholz, one of the premier comet-hunters of his time.

Geminid meteor shower

Meteors

Update on a Possible Outburst of Meteors

Will there be a new meteor shower on the night of May 30–31? There's only one way to find out.

Two crescents meet

Occultations

Watch the Moon Pair Up with Venus on June 19th

Two crescents — the Moon and Venus — meet in the sky in the wee hours of June 19th.

Comet Triple Crown

People, Places, and Events

Comet 46P/Wirtanen Approaches Earth

On December 16th, the comet will pass within 12 million kilometers of Earth and should brighten to about 3rd magnitude, though the diffuse coma and a nearly full Moon will make observations difficult.

Solar System

Solar Eclipse Made Bow Waves in Earth's Atmosphere

New research shows that the supersonic motion of the Moon's shadow across the continental U.S. in August 2017 created bow waves in Earth's atmosphere.

Moon's shadow from space

The 2017 Total Solar Eclipse

“Observe” August's Eclipse with Your AM Radio

When the Moon's shadow glides across the U.S. on August 21st, you'll have have a chance to hear the eclipse as it happens.

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