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Mars, Pollux, Castor in twilight, early June 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, June 4 – 12

Pollux and Castor slide down past Mars in the west, while Venus, shining brightly below, tries to hog attention. On the other side of the sky, the enormous arch of the Milky Way hoves into view after dark behind the Summer Triangle.

Moon Venus Mars on June 11-13, 2021

Sky Tour Astronomy Podcast

June: Solar Eclipse & Colorful Stars

June features long days and short nights in the Northern Hemisphere, so download our narrated Sky Tour astronomy podcast to make the most of the abbreviated dark hours after sunset. Special event: a partial solar eclipse on June 10th!

Venus-Mercury conjunction at dusk, May 28, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, May 28 – June 5

Venus and Mercury conjoin in the post-sunset afterglow as Mercury fades away; bring binoculars! Arcturus stands over Spica. The Scorpion rears up, and the Big Dipper floats on high.

Celestial Objects to Observe

Dawn Delight: Catch the Total Lunar Eclipse on May 26, 2021

On May 26th the Moon will be in total eclipse for the first time in nearly two and a half years. While timing favors western North America, a partial eclipse will be visible across much of the U.S. and Canada at dawn.

Jupiter on May 17, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, May 21 – 29

The Moon waxes from gibbous to supermoon-eclipse full. Low at dusk, Venus and Mercury close in on each other. Nova Cas has dropped back. And at dawn, Jupiter and Saturn climb a bit into slightly better view.

Moon passing Mars in Gemini, May 15-16, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, May 14 – 22

The crescent Moon waxes across the evening sky, pairing with Mars in upright-standing Gemini and then, four days later, with Leo's forefoot Regulus. In a telescope, Jupiter and Saturn are becoming not quite so fuzzy as they gain more altitude in early dawn.

V1405 Cas scene

Stellar Science

Nova in Cassiopeia Brightens Suddenly

A star in the constellation Cassiopeia that flared into view during mid-March has erupted to naked-eye visibility. Catch it while you can!

Moon, Mercury, Venus at dusk, May 12-13, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, May 7 – 15

Mercury and low Venus adorn the west after sunset, with the crescent Moon soon to join them. Night brings the big Diamond of Virgo and Summer Triangle. Nova Cassiopeiae rebrightens. And Comet Atlas is in evening view with a 6-inch telescope.

HD 122563 closeup

Observing

In Search of Ancient Suns

We track down and admire five of the most ancient stars in the universe.

Moon-Mercury-Venus on May 12-13

Sky Tour Astronomy Podcast

May: Halley Bits & Lunar Eclipse

Exciting celestial events will happen during May, so download our narrated Sky Tour astronomy podcast to find out about this month's Eta Aquariid meteor shower and a total lunar eclipse.

Moon with Jupiter and Saturn at dawn, May 3-5, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, April 30 – May 8

Mercury and Venus now show themselves better at dusk. After dark, Comet Atlas awaits telescopic skyhunters. And the waning Moon passes under Saturn and Jupiter in early dawn.

full Moon

Celestial Objects to Observe

7 Easy Things to See on the “Supermoon”

Seven easy and rewarding targets to explore when the Moon is full.

Venus and Mercury barely above the sunset horizon, April 25, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, April 23 – May 1

Day by day, Venus and Mercury creep up from the sunset horizon in bright twilight. High above as twilight fades away, trace out the Arch of Spring arching high over Mars. Meanwhile Arcturus dominates the east.

Hubble photo of M3

Celestial Objects to Observe

Hunting Barnard's Variable in the Globular Cluster M3

We beat a path through a forest of stars to find the first variable star ever discovered in a globular star cluster.

Moon crossing Leo, April 21-22, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, April 16 – 24

The waxing Moon this week steps out of Taurus past Mars, across Gemini and Cancer, and into Leo. Sirius and Procyon remain in the southwest after dusk. Jupiter and Saturn shine in early dawn.

Three novae

Celestial Objects to Observe

A Bouquet of Novae Brightens April Nights

With the recent discovery of Nova Scorpii 2021 earlier this week, three bright stellar explosions are now visible in small telescopes from dusk till dawn.

Crescent Moon with Aldebaran and Pleiades, April 15-16, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, April 9 – 17

Arcturus ascends in the east as Sirius sinks in the southwest. Orion tilts further as the Dipper rides high. And this week Mars threads the horntips of Taurus, closely followed by the crescent Moon.

Solar System

Make the Most of Comet ATLAS

Bright comets will be scarce this year, but you can see one of the better ones this month as it races from Aquila to Canes Venatici. In other news, a new, bright nova has flared in Sagittarius.

The waning Moon passes under Saturn and Jupiter at dawn, April 6-7, 2021

This Week's Sky At a Glance

This Week's Sky at a Glance, April 2 – 10

Winter stars in the west are giving way to spring stars in the east, while little Mars shines on. Meanwhile, the waning Moon passes under Jupiter and Saturn at dawn.

Moon pairings in April 2021

Sky Tour Astronomy Podcast

April: Follow the Moon

To learn “what’s up” at night during April, download Sky Tour — an engaging narrated guide to the planets, stars, and constellations now visible.