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Moon occults Kappa Geminorum (Chris Vaughan, Starry Night Education)

This Week’s Sky: February 22 to 28, 2021

The Moon passes Kappa Geminorum and buzzes the Beehive this week on the way to its full stage.

Tuesday, February 23 – Mercury swings toward Saturn (pre-dawn)

Mercury swings toward Saturn (Chris Vaughan, Starry Night Education)

On the mornings surrounding Tuesday, February 23, the orbital motion of Mercury will bring it within several finger widths of Saturn. At closest approach on Tuesday, magnitude 0.5 Mercury will sit 4 degrees left (celestial northeast) of slightly dimmer Saturn. Use binoculars (red circle) to look for the two planets sitting just above the southeastern horizon after they rise at about 6 a.m. local time. Brighter Jupiter will rise about 20 minutes after them.

Tuesday, February 23 – Moon passes Kappa Geminorum (at 6:40 p.m. EST)

Moon passes Kappa Geminorum (Chris Vaughan, Starry Night Education)

On Tuesday evening, February 23, observers in Canada and South America will see the Moon graze or closely miss medium-bright star Kappa Geminorum (or κ Gem). Observers in the eastern continental United States and Central America can watch the waxing gibbous Moon occult the star. The time of the pass (or occultation) varies by latitude. Use Starry Night or another astronomy app to look up the times where you live, but remember to start watching a few minutes before the appointed times. The event will be observable in binoculars and backyard telescopes, but remember that a telescope (red circle) will likely invert and/or mirror the scene shown here.

Wednesday, February 24 – Moon buzzes the Beehive (all night)

Moon buzzes the Beehive (Chris Vaughan, Starry Night Education)

After dusk on Wednesday, February 24, the nearly full Moon will be positioned just two finger widths to the upper left (or 2 degrees to the celestial north) of the large open star cluster known as The Beehive (or Messier 44) in the constellation of Cancer. These encounters occur frequently because the cluster is located only one degree north of the ecliptic (green line). The Moon and the cluster will both fit within the field of view of binoculars (red circle), but the Moon’s brilliance will mostly overwhelm the clusters’ stars. To see more stars, try placing the Moon just outside your optics’ field of view. During the night, the diurnal rotation of the sky will shift the Moon above the Beehive.

Saturday, February 27 – Full Snow Moon (at 8:17 GMT)

Full Snow Moon (Chris Vaughan, Starry Night Education)

The February full Moon, known as the Snow Moon or Hunger Moon, always shines in or near the stars of Leo. Since it is opposite the Sun on this day of the lunar month, the Moon is fully illuminated, and rises at sunset and sets at sunrise. When full, no shadows are cast by the lunar terrain — so all of the albedo variations are produced by the Moon’s geology.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.

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