SkyEye

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. This year finds Mercury in the morning skies four times and the evening skies thrice.

The first morning apparition of 2019 (blue track) finishes the last morning apparition of 2018, with Mercury vanishing in the southeast before February. The second morning apparition (pink track) is by far the best this year, with Mercury soaring to an altitude of almost 27° and brightening throughout. The next apparition (green track) in July and August is not as good. The closest planet to the Sun manages only half the altitude of the previous apparition. Mercury's final morning appearance in 2019 (orange track) is similar to its first and continues into next year. Although the planet does not gain much altitude, it is fairly bright for much of the apparition.

The first evening apparition of Mercury (blue track) is the least favourable one at this southern latitude. It never gets even as high as 10° in altitude although it is quite bright until early March. The next apparition (pink track) is much better, with Mercury rising twice as high as that in late June. However, although the planet starts off at magnitude −2.2, it dims to an unobservable sixth magnitude before the end of the apparition. The final apparition of September–October–November (green track) is the best, with zero magnitude Mercury a commanding presence in October at an altitude of nearly 24°.

Venus

Venus spends the first part of the year as the morning star then switches to western skies in August.

Continuing from last year, the morning apparition of Venus is an excellent one for southern hemisphere observers. It continues to gain altitude into February, eventually reaching 41°, before descending steadily in the northeast. The planet is brightest at the beginning of the year (magnitude −4.5) and slowly dims to magnitude −3.9 by the time it vanishes in July.

This is a mediocre apparition of the evening star. It appears low in the west at the end of August and climbs slowly, reaching a maximum altitude of only 27° by the end of the year. The apparition continues into 2020, with the planet slowly descending for four months before precipitously dropping back toward the northwestern horizon. The planet brightens slightly from magnitude −3.9 to −4.0 between September and the end of the year.

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.