When the weather cooperates, October makes for excellent stargazing. The Milky Way lingers in the west along with stars that were prominent in the northern summer. The autumn stars dominate overhead, and the northern winter stars are starting to poke above the eastern horizon. Best of all, you can get in a good night of stargazing without staying up too late. Jupiter and Saturn remain prominent, both still big enough for promising telescopic observation. Mars continues to grow and brighten in Taurus. Mercury makes its best morning appearance of the year for northern stargazers. And the Orionid meteor shower arrives in nearly ideal conditions. Here’s what to see in the night sky this month…
3 Oct. First Quarter Moon, 00:14 UT
6 Oct. The waxing gibbous Moon lies almost exactly between Jupiter and Saturn. Jupiter, just past opposition last month and in Pisces, still blazes at magnitude -2.9 with a disk nearly 50” across. You can’t hope for a better view of the planet if you have steady skies. Saturn also presents a pleasing sight though it’s smaller and dimmer in the eastern horn of Capricornus. But, oh, those rings! The planet shines at magnitude +0.5 and its disk spans about 18”.
8 Oct. Mercury makes its most accessible appearance in the morning sky in 2022 for northern-hemisphere observers. Today, this smallest major planet reaches its greatest western elongation about 18o from the Sun. It sits about 10o above the eastern horizon well before sunrise and about 15o below the eastern section of the constellation Leo. No other bright stars or planets nearby. At magnitude -0.5 today, Mercury appears nearly half lit in a telescope. In the next several days, Mercury increases slightly in brightness then moves quickly back to the horizon on its way to superior conjunction next month.
9 Oct. Full Moon, 20:55 UT
11-12 Oct. The Moon passes in front of Uranus on the night and morning of Oct. 11-12 for observers in northwestern Mexico, the western U.S., and much of Canada. Precise times depend on location, but from my location in Calgary, Canada the occultation begins at 11:14 p.m. MDT on Oct. 11 when Uranus disappears behind the bright limb of the waning gibbous Moon, and ends as it reappears from behind the dark limb at about 12:19 a.m. MDT on Oct. 12. More precise timing for other locations is available at this link:
http://www.lunar-occultations.com/iota/planets/1012uranus.htm
The glare of the Moon means observing the planet’s disappearance presents more of a challenge than spotting its return as it emerges from the Moon’s darkened limb. You’ll need a small telescope to see this event.
14 Oct. Look for Mars about 3o south of the 20-day-old Moon. The planet lies in the horns of Taurus rising in the eastern sky after dark. Mars shines at an impressive magnitude -0.9 and spans a little more than 13”. In a telescope at high magnification – if you have steady air – the planet may offer up a little surface detail. The view only gets better for the next two months as the Earth catches up to Mars on the way to opposition on Dec. 8.
17 Oct. Last Quarter Moon, 17:15 UT
21 Oct. At last – a good meteor shower! The Orionids, one of the best of the year, peak in the early morning hours today. They usually show as many as 20-40 fast-moving meteors per hour in dark sky. The shower’s radiant lies near the top of the club of Orion, but these meteors can appear anywhere in the sky and trace their paths back to the radiant. Maximum activity usually occurs between midnight until dawn. The waning crescent Moon doesn’t much interfere with the faintest meteors this year. Like the Eta Aquariids in May, the Orionids are tiny pieces of Comet 1/P Halley that strike the upper atmosphere as the Earth passes through the famous comet’s debris field.
22 Oct. Venus reaches superior conjunction and lies on the far side of the Sun from Earth. The planet will slowly emerge into the evening sky and become visible again in December.
25 Oct. New Moon, 10:49 UT
25 Oct. Observers in most of Europe (except for Portugal and much of Spain) will see a partial solar eclipse today. The eclipse occurs from 08:58 UTC to 13:02 UTC, with greatest eclipse happening at 11:00 UTC. To see this event, you MUST use a safe solar filter as the Sun will appear far too bright to observe directly. For maps and links to precise time, see the page for this eclipse at EclipseWise.com.