The 4 Galilean moons — Io, Europa, Ganymede, and Callisto — orbit with durations of two to 16 days. Previous opposition, the moons transit forward of their shadows. A sequence of Europa transits adopted by Io occultations happen Oct. 8, 15/16, and 22/23. Every of those is adopted by an Io transit on the evenings of Oct. 9, 16, and 23.
On Oct. 8, Europa’s transit begins at 8:49 P.M., its shadow begins to transit at 9:25 P.M., and Io disappears at 10:42 P.M. (all occasions EDT). On Oct. 15/16, occasions happen in the identical order at 11:03 P.M., 12:01 A.M., and 12:26 A.M. (the final two occasions are on the sixteenth for these within the Japanese time zone solely). On Oct. 23, occasions are in a barely completely different order: Europa transits beginning at 1:18 A.M., Io disappears at 2:11 A.M., and Europa’s shadow slips onto the disk at 2:36 A.M. (Some or all occasions happen late on the twenty second in western time zones.) Additionally on the twenty second, Ganymede is occulted by Jupiter at 11:30 P.M. EDT.
Io and its shadow transit the day after every of the Europa occasions. These transits (moon, shadow) happen at 7:53 P.M. and eight:14 P.M. on the ninth, 9:38 P.M. and 10:09 P.M. on the sixteenth, and 11:24 P.M. (Oct. 23) and 12:05 A.M. (Oct. 24 for East Coast observers solely; all occasions are once more EDT). Notice how the time between every moon and shadow transit stretches as October progresses — a function of Earth’s altering view of the Jupiter system relative to the course of daylight.
The following planet alongside the ecliptic, Uranus, is occulted by the Moon Oct. 11/12. Uranus at the moment lies within the sparse areas of southeastern Aries.
These within the northwestern U.S. will see the occultation. Others will see a close to miss, with Uranus south of the Moon. It’s difficult to see magnitude 5.7 Uranus reappear close to such a brilliant Moon, however there’ll be plenty of curiosity. The timing of the occasion is closely location-dependent however happens round 11:45 P.M. (For instance, residents of Denver see Uranus seem at about 11:52 P.M. MDT on the eleventh). Observers within the jap U.S. will see an analogous occasion on the primary day of 2023.
Uranus is approaching subsequent month’s opposition. To seek out it, find magnitude 2.5 Menkar in Cetus. Uranus stands about 12° due north of the star, barely lower than two discipline diameters in 7×50 binoculars. The aqua-colored planet is situated between Sigma (σ) and 53 Arietis all month.
Via a telescope, attempt to discern the 4″-wide disk. At greater than 1.7 billion miles from Earth, it’s a fabulous sight. Use increased magnifications on nights of excellent seeing for the most effective views.
Mars is a surprising object in the course of Taurus on Oct. 1. It’s now solely two months from opposition as we enter the most effective time to watch the Pink Planet. Mars rises round 10 P.M. and brightens from magnitude –0.6 to –1.1 in the course of the month. It kinds a surprising triangle with two brilliant purple big stars: Betelgeuse to its south and Aldebaran to its west.
The Moon joins Mars late on Oct. 14, separated by lower than 4°. The Pink Planet additionally stands inside 1.1° of the Crab Nebula (M1) for about three days beginning on this date, passing due north of the nebula on the seventeenth. The planet’s eastward movement slows to a halt by Oct. 30, when it sits 2.7° north of Zeta (ζ) Tauri. It then begins a retrograde path.
Mars transits the native meridian round 5 A.M. That is the most effective time to view the planet or document high-speed video, and ideal your observing methods. Its obvious diameter grows from 12″ to fifteen” in the course of the month, and its phase grows from 88 % to 94 %.
Within the hours round native midnight, the next options face Earth (for Midwestern observers): Oct. 1: Olympus Mons; Oct. 5: Tharsis Ridge and Valles Marineris; Oct. 14: Solis Lacus; Oct. 22: Syrtis Main and the Hellas basin; Oct. 30: Mare Sirenum. Get pleasure from changing into aware of these options as Mars approaches its early December opposition.
