Every week, SkyNews publishes a list of key events in the Canadian sky in This Week’s Sky. This series gives you all the latest news in Solar System movements, including where the planets are in our sky and Moon phases. From eclipses to meteor showers, This Week’s Sky keeps you updated on the best in upcoming astronomical highlights.
Tuesday, July 19 – Half-Moon passes Jupiter (midnight to dawn)
The Moon’s trip past the string of bright planets will continue between midnight and dawn on Tuesday morning, July 19. When the waning, half-illuminated Moon clears the eastern treetops during the wee hours, it will be shining several finger widths below (or 3 degrees to the celestial southeast of) the bright dot of Jupiter — easily close enough for them to share the view in binoculars. By the time the sky begins to brighten ahead of sunrise, the pair will be halfway up the southern sky. The Moon will remain visible in the morning daytime sky, allowing you to seek out Jupiter in daylight by positioning the Moon towards the left of your binoculars’ field of view (inset). Once you see Jupiter, try finding its bright pinpoint without aid.
Wednesday, July 20 – Third quarter Moon (at 14:19 UTC)
The Moon will complete three quarters of its orbit around Earth, measured from the previous new Moon, on Wednesday, July 20 at 10:19 a.m. EDT or 7:19 a.m. PDT and 14:19 UTC. At the third (or last) quarter phase the Moon appears half-illuminated, on its western, sunward side. It will rise around midnight local time, and then remain visible until it sets in the western daytime sky in early afternoon. Third quarter moons are positioned ahead of the Earth in our trip around the Sun. About 3.5 hours later, Earth will occupy that same location in space. The week of dark, moonless evening skies that follow this phase are the best ones for observing deep-sky targets.
Wednesday, July 20 – Pluto at opposition (all night)
On Wednesday, July 20, the dim and distant dwarf planet designated (134340) Pluto will reach opposition for 2022. On that date, the Earth will be positioned between Pluto and the Sun, minimizing our distance from that outer world and maximizing Pluto’s visibility. While at opposition, Pluto will be located 3.12 billion miles, 5.02 billion km, or 279 light-minutes from Earth. Unfortunately, it will shine with an extremely faint visual magnitude of +14.3 that is far too dim for visual observing through backyard telescopes. Pluto will be located in the sky about 3 finger widths above (or 3.5 degrees to the celestial north of) the medium-bright star Omega Sagittarii, which shines well to the left (east) of Sagittarius’ Teapot-shaped asterism. Alternatively, seek out Pluto’s position two degrees to the lower right of the globular star cluster Messier 75. Even if you can’t see Pluto directly, you will know that it is there.
Thursday, July 21 – Crescent Moon meets Mars (pre-dawn)
When the waning crescent Moon becomes visible low in the eastern sky during the wee hours of Thursday morning, July 21, it will be positioned several finger widths to the upper right (or 4 degrees to the celestial west-southwest) of Mars’ reddish dot — cosy enough to share the view in binoculars. By the time the sky begins to brighten around 5 a.m., the Moon and Mars will be halfway up the southeastern sky. On the following morning, the Moon will hop to sit to Mars’ lower left (celestial east). In the interim, observers in eastern China, Japan and northeastern Russia can watch the Moon occult Mars around 15:00 UTC.
Friday, July 22 – Crescent Moon points to Uranus (before dawn)
For about two hours on Friday morning, July 22, before the sky begins to brighten, the waning crescent Moon will allow you to find the tiny dot of the magnitude 5.8 blue-green planet Uranus in binoculars (green circle) and backyard telescopes. The Pleiades cluster and reddish Mars will shine nearby. When the Moon rises after 1 a.m. local time in the Eastern Time Zone, Uranus will be located a lunar diameter above (or celestial northwest of) the Moon. The Moon’s eastward orbital motion (green line) will carry it steadily farther to Uranus’ lower left each hour, so observers looking later, and in more westerly time zones, will find Uranus up to 3 degrees from the Moon. Skywatchers from northeastern Brazil to the Cape Verde Islands and northwestern Africa can watch the Moon occult Uranus around 04:30 UTC.
Saturday, July 23 – Old Moon travels Taurus (pre-dawn)
Early risers on Saturday, July 23 can see the delicate crescent of the old Moon shining above the stars of Taurus, the Bull, in the eastern sky. Try to look before dawn brightens the sky too much. The pretty Pleiades star cluster, also known as the Seven Sisters and the Hole in the Sky, will be poised several degrees above the Moon. The bright orange star Aldebaran will twinkle a fist’s diameter below (or about 10 degrees to the celestial southeast). Binoculars will show the Hyades cluster, a triangle of many stars that outline Taurus’ face to the upper right of Aldebaran. The Bull’s two horns will be tilted downwards to the left (or celestial northeast).
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.