SkyEye

Solar System Phenomena — 2023 Apparitions of the Inferior Planets from Latitude 30° South

What is an Apparition?

An apparition of a planet is the period during which it is visible, beginning and ending with solar conjunction. In the cases of the inferior planets Mercury and Venus, it is the time between inferior and superior conjunction (morning apparition) and the time between superior and inferior conjunction (evening apparition). Because inferior planets are always near the Sun, they only appear in the east before sunrise and the west after sunset.

Below are a series of diagrams showing the morning and evening apparitions of Mercury and Venus as observed from latitude 30° south. The planet is shown on the 1st, 6th, 11th, 16th, 21st and 26th days of each month with the current year's positions shown in bright white. The path may extend from the previous year or into the next.

Mercury

Mercury undergoes several morning and evening apparitions every year. Morning apparitions occur between inferior conjunction (when the planet is at its dimmest) and superior conjunction (when the planet is at its brightest) whereas evening apparitions always start bright and end with the planet around sixth magnitude. Mercury appears both at dawn and at dusk four times in 2023.

21 December2022greatest elongation east: 20.1°
07 January2023inferior conjunction
30 Januarygreatest elongation west: 25.0°
17 Marchsuperior conjunction
11 Aprilgreatest elongation east: 19.5°
01 Mayinferior conjunction
29 Maygreatest elongation west: 24.9°
01 Julysuperior conjunction
10 Augustgreatest elongation east: 27.4°
06 Septemberinferior conjunction
22 Septembergreatest elongation west: 17.9°
20 Octobersuperior conjunction
04 Decembergreatest elongation east: 21.3°
22 Decemberinferior conjunction
12 January2024greatest elongation west: 23.5°

The morning apparitions of Mercury in 2023 as seen from latitude 30° south.

After opening the year in the evening skies, Mercury appears at dawn in mid-January (blue track), rising rapidly above the horizon to peak at 22.9° in altitude at the beginning of February and falling away just as quickly. The May–June apparition is the best morning appearance for this latitude, with zero-magnitude Mercury looping up to over 23° in late May. The next appearance in September and October (green track) may be difficult to observe, with Mercury barely reaching an altitude of 9°. The year concludes with the tiny planet appearing in late December (orange track) and rapidly climbing to over 12° in height.

The evening apparitions of Mercury in 2023 as seen from latitude 30° south.

The final apparition of 2022 ends just a few days into 2023 (blue track) with Mercury appearing low (only 8.1°) in the west-southwest and soon vanishing. The next evening appearance from mid-March to the end of April (pink track) is the worst complete evening apparition of the year for planet watchers at 30°S with the tiny planet not reaching 9° in altitude. This is followed by the best viewing opportunities (green track) in July, August and early September when Mercury soars to over 26° above the horizon. Mercury makes one final appearance in late October (orange track) before disappearing just before the end of the year. Look for the zero-magnitude object over 19° high in the west-southwest in early December as it rises and falls quickly.

Venus

Venus begins the year as the evening star, moving into the morning sky in mid-August.

22 October2022superior conjunction
04 June2023greatest elongation east: 45.4°
13 Augustinferior conjunction
23 Octobergreatest elongation west: 46.4°
04 June2024superior conjunction

The morning apparitions of Venus in 2023 as seen from latitude 30° south.

The 2023 morning apparition of Venus is at best mediocre. Although it quickly gains altitude throughout late August and September, the bright planet then hovers just under 30° above the horizon for most of the rest of the year.

The evening apparitions of Venus in 2023 as seen from latitude 30° south.

Last year's evening apparition continues until mid-August 2023, with Venus reaching a maximum altitude of 34.8° by the end of June and a maximum brightness of magnitude −4.5 a few days later. The evening star bows out just before inferior conjunction on 13 August.

Sources

The dates, times and circumstances of all planetary and lunar phenomena were calculated from the JPL DE406 solar system ephemeris using the same rigorous methods that are employed in the compilation of publications such as The Astronomical Almanac.