SkyEye: September 2024

Welcome to SkyEye, your guide to this month's celestial events!

All times and dates are in UT with the time given to the nearest 30 minutes.
Planetary positions are geocentric apparent places, referred to the true equator and equinox of date.

The phases of the in September 2024

Day	Events
1	Uranus reaches its maximum northerly declination for the year, shortly before it enters into retrograde motion. The old crescent Moon passes 5.0° north of Mercury at 10:30 in dawn skies.
2
3	NEW MOON
4
5	Mercury arrives at its greatest elongation west of 18.1° today. The Moon passes through its descending node and then occults Venus beginning at 09:00. Our satellite arrives at apogee later in the day.
6	Mars moves through its ascending node and will remain north of the ecliptic plane for the rest of the year. At 16:30, the waxing crescent Moon occults the first-magnitude star α Vir (Spica).
7
8	Saturn is at opposition today. It shines at magnitude +0.7 and exhibits a narrow ring tilt of just 3.7° as viewed from Earth.
9	Mercury is just 0.4° north of the first-magnitude star α Leo (Regulus) at 02:00. The peak of the minor September ε Perseid meteor shower occurs around 06:00.
10	At 12:30, the waxing crescent Moon occults α Sco (Antares).
11	FIRST QUARTER MOON
12	Jupiter reaches west quadrature.
13
14
15
16
17	Saturn is occulted by the Moon from 08:30.
18	At 03:00, Venus is found 2.2° north of the first-magnitude star α Vir (Spica). The FULL MOON, traditionally called the Harvest Moon in the northern hemisphere, takes part in a partial lunar eclipse. Afterwards, the Moon occults Neptune (this events begins around 05:30), reaches perigee, and moves through its ascending node.
19
20	Neptune is at opposition, 28.9 au away from Earth and shining at a meagre magnitude +7.8.
21
22	The waning gibbous Moon occults the open star cluster M45 (Pleiades) at 10:30. Also today, Earth reaches an equinox.
23
24	The LAST QUARTER MOON is 5.8° north of Jupiter at 00:30.
25	At 13:00, the Moon passes 4.9° north of Mars.
26	At 10:30, the waning crescent Moon is 1.6° south of β Gem (Pollux).
27	The Moon is found 3.1° north of the open star cluster M44 (Beehive) at 11:00.
28
29	At 11:00, the Moon is 3.0° north of the first-magnitude star α Leo (Regulus).
30	Mercury is at superior conjunction.

The position of the Sun and planets at mid-September 2024

Sun Leo → Virgo

Mercury Leo This is the best morning apparition of Mercury this year for observers in northern temperate latitudes. Greatest elongation east takes place on the fifth day of the month. The tiny planet brightens throughout September, starting out at magnitude +0.6 and ending at −1.7 during superior conjunction on 30 September. Look for Mercury after sunset early in September, before it heads back toward the horizon and its rendevous with the Sun.

Venus Virgo → Libra The evening star remains low to the western horizon for observers in northern latitudes but is gaining altitude quickly for those looking from the southern hemisphere. Venus makes a pretty picture with the waxing crescent Moon, with the two objects 1.2° apart at 11:30 on 5 September; some places on Earth will witness a lunar occultation event. The bright planet is 2.2° north of Spica on 18 September and passes through its descending node on 25 September; it will remain south of the ecliptic for the remainder of the year.

Earth and Moon Earth arrives at an equinox on 22 September which heralds spring in the southern hemisphere and autumn in the north. The Moon occults the usual suspects: Spica, Antares, and the Pleiades, plus Venus. It is also partially eclipsed on 18 September. This Full Moon is the one taking place nearest to the equinox and is traditionally called the "Harvest Moon" in the northern hemisphere.

Mars Taurus → Gemini The red planet is slowly getting brighter, from magnitude +0.7 to +0.5 over the course of the month, and looks bigger and more gibbous in the telescope. It rises in late evening for northern observers (midnight or later for those in the southern hemisphere) and at 16:30 on 7 September, passes 0.9° south of the open cluster M35. Later that same day, Mars approaches to within 0.1° of the fourth-magnitude star 1 Gem. Mars continues its journey through Gemini, passing a number of the brighter stars in the constellation: Propus or η Gem on 11 September (0.9° apart), Tejat or μ Gem on 14 September (0.9° apart), and finally Mebsuta or ε Gem on 23 September (1.9° apart).

Jupiter Taurus Jupiter reaches west quadrature mid-month and finally starts appearing in the east before midnight by the end of September.

Saturn Aquarius Saturn is at opposition on 8 September and is visible for most of the night. It is at its biggest and brightest during this time but the rings are less than 4° open as ring-plane crossing approaches next year. It is occulted by the Moon on 17 September.

Uranus Taurus Dark skies are always a requirement if you wish to spot this planet with the naked eye. Sixth-magnitude Uranus enters into retrograde motion at the beginning of the month and is visible from mid-evening.

Neptune Pisces A small telescope is necessary to view the most distant planet in the solar system. Like Saturn, Neptune arrives at opposition this month and is visible, albeit with optical aids, all night. It is occulted by the Full Moon on 18 September, two days before opposition.