The sky this week for October 10 to 14
Mars continues to put on a great show these October evenings. The Red Planet appears some 30° above the southern horizon once darkness falls. The world shines at magnitude –1.1, significantly brighter than any star visible on October evenings, against the faint backdrop of central Capricornus. A telescope reveals a disk that spans 14″ and shows several subtle surface features.
Thursday, October 11
Look low in the west-southwest after sunset and you’ll see a slender crescent Moon standing 4° above Jupiter. The pretty pair stands nearly 10° above the horizon an hour after sunset and sets shortly after the last vestiges of twilight fade away. Jupiter shines at magnitude –1.8 among the background stars of Libra the Scales. Although it is the brightest point of light in the sky, it lies too low to show much detail through a telescope.
Friday, October 12
The night sky’s most conspicuous harbinger of winter now rises in the east around midnight local daylight time. The constellation Orion the Hunter appears on its side as it rises, with ruddy Betelgeuse to the left of the three-star belt and blue-white Rigel to the belt’s right. As Orion climbs higher before dawn, the figure rotates so that Betelgeuse lies at the upper left and Rigel at the lower right of the constellation pattern.
Uranus reaches opposition in just 10 days, and it is already a tempting evening target. The ice giant world rises during twilight and climbs 30° above the eastern horizon by 9:30 p.m. local daylight time. The magnitude 5.7 planet lies in the southwestern corner of Aries, 10° due south of the Ram’s second-brightest star, 3rd-magnitude Beta (β) Arietis. Although Uranus glows brightly enough to see with the naked eye under a dark sky, binoculars make the task much easier. A telescope reveals the planet’s blue-green disk, which spans 3.7″.
Sunday, October 14
Saturn stands 1.5° to the left of the waxing crescent Moon this evening. The two lie 20° above the southwestern horizon at the end of twilight and remain on view until after 10 p.m. local daylight time. The ringed planet shines at magnitude 0.5 this week, more than a full magnitude brighter than any of the background stars in its host constellation, Sagittarius. If you own a telescope, there’s no better target than Saturn. Even the smallest instrument shows Saturn’s 16″-diameter disk surrounded by a dramatic ring system that spans 37″ and tilts 27° to our line of sight.