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.
Monday, September 26 – Jupiter closest at opposition (all night)
On Monday, September 26, Jupiter will reach opposition among the stars of western Pisces. Because Jupiter’s 12 year orbit is approaching perihelion on January 20, 2023, this will be the planet’s closest approach to Earth since 1963, and the closest until 2129. On opposition night, Jupiter will rise at sunset, remain visible all night long, and set at sunrise. Its minimal distance from Earth of 591.3 million kilometres or 32.9 light-minutes, will produce a maximum brightness of magnitude -2.94. Viewed in a telescope (inset), the planet will display a generous, 49.9 arcsecond-wide disk striped with equatorial bands. Around opposition, Jupiter and its four large Galilean satellites frequently eclipse and occult one another, and cast their round, black shadows on the planet singly and in pairs. The Great Red Spot appears every second or third night.
Friday, September 30 – Crescent Moon above Antares (evening)
In the southwestern sky after dusk on Friday, September 30, the crescent Moon will shine only a thumb’s width above (or 1.5 degrees to the celestial northeast of) the bright, reddish star Antares in Scorpius. Antares’ location just 4 degrees south of the ecliptic means that the Moon, and even the occasional planet, can occult it. Antares’ name arises from an ancient Greek expression for “rival to Ares,” which we know better as the planet Mars.
Saturday, October 1 – Delphinus swims the southern sky (all night)
During evening in early October, the small constellation of Delphinus is positioned high in the southern sky. Look for its five 4th magnitude stars shining just to the lower left (or celestial southeast) of the line connecting the bright stars Deneb and Altair. According to Greek legend, Poseidon, god of the seas, was assisted in a matter of the heart by a friendly dolphin, so he rewarded it with a place of honour in the heavens. Delphinus’ brightest two stars are bluish Sualocin, at the top of its head, and whitish Rotanev, at the nape of its neck. Those funny appellations are actually the name of 19th century astronomer Nicolaus Venator spelled backwards. Gamma Delphinus, the star marking the dolphin’s nose, is a close-together double star with one component a greenish colour. Despite swimming close to the Milky Way, Delphinus’ only prominent deep sky objects are two globular clusters designated NGC 7006 and NGC 6934, which are also numbers C42 and C47, respectively on Sir Patrick Moore’s Caldwell List.
Sunday, October 2- First quarter Moon (at 8:14 p.m. EDT)
The Moon will complete the first quarter of its journey around Earth on Sunday, October 2 at 8:14 p.m. EDT or 5:14 p.m. PDT. That translates to Monday, October 3 at 00:14 GMT. At first quarter, the Moon’s 90 degree angle from the sun will cause us to see it half-illuminated – on its eastern side, and shining among the Teapot-shaped stars of Sagittarius after dusk. At first quarter, the Moon always rises around mid-day and sets around midnight, so it is also visible in the afternoon daytime sky, too. The evenings surrounding first quarter are the best ones for seeing the lunar terrain when it is dramatically lit by low-angled sunlight, especially along the terminator, the pole-to-pole boundary that separates the lit and dark hemispheres.
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.