Sky-watchers enjoy parting views of Saturn, the “lord of the rings,” this week, along with the moon joining a star cluster and a historic encounter between the red planet and an icy interloper.
Sinking Saturn. Starting Tuesday, October 14, sky-watchers get their last chance to see Saturn as it quickly continues to sink in the southwest evening sky.
Small telescopes reveal a grand view of those stunning rings around the gas giant, ones tilted 23 degrees towards Earth, even through the glow of the sunset. To find Saturn, observers should find a clear view of the southwest horizon about 30 to 45 minutes after sunset. Viewers in the more southerly latitude will find the yellow-tinged planet, now located in the constellation Libra, farther away from the sun, making it easier to spot.
Stellar Crown. In the early morning hours of Wednesday, October 15, the waning moon appears high in the southeast sky, surrounded by the brightest stars of wintertime.
The closest ones appear to be Orion constellation’s Betelgeuse, Canis Minor’s Procycon, and Gemini’s Pollux.
Moon Buzzes Beehive. Before dawn on Friday, October 17, look for the waning crescent moon in the southeast sky. While brilliant starlike Jupiter is to its left, use binoculars to track down the Beehive star cluster.
Located in the constellation Cancer, the Crab, the stunning open cluster of stars also known as Messier 44 is bright enough to be just visible to the naked eye as a fuzzy spot. At 610 light years, it is one of the closest clusters to Earth.
Binoculars and small telescopes, however, will reveal that about six dozen member stars stretch across 11 light years of space. They span the same stretch of Earth’s sky that two full moon disks take up.
The Moon Meets Jupiter. On Saturday, October 18, rise early and look for the thin crescent moon at its closest approach, with bright Jupiter perched above it.
The cosmic duo will be separated by only seven degrees—a little more than the width of your fist at arm’s length. It is amazing to think that the king of all planets lies 47 light-minutes away while our moon is only 1.5 light-seconds distant.
Comet Passes Mars and Cluster. On Sunday, October 19, Comet Siding Spring (C/2013 A1) barnstorms the Mars, missing the planet by only 87,000 miles (139,500 kilometers). This will be less than half the distance of Earth to the moon, the closest pass of a comet by Mars in recorded history. Closest approach will be at 2:26 pm EDT.
Telescope users up for the challenge can try to hunt down the magnitude-11 comet low in the southwest skies about 45 minutes after sunset. Siding-Spring will appear about 10 arc-minutes from Mars, less than a third the width of the full moon in the sky.
The globular cluster NGC 6401 will be just one degree above Mars, which is less than the wide of two full moon disks. The 35,000-light-year distant cluster will be shining at only 9.5, magnitude so it will be visible through six-inch telescopes and larger. However, this cosmic trio may make for an interesting photographic challenge for seasoned telescope imagers.
Here is a detailed finder’s chart from astronomy.com for telescope users.
And if the comet eludes you, check out a live webcast of the close encounter via the Virtual Telescope project.