Special to CosmicTribune.com, October 20, 2024

Excerpts from weekly Sky&Telescope report.

SUNDAY, OCTOBER 20

■ For most Northern Hemisphere observers, this is the first evening in more than a week that offers a brief window of Moon-free darkness for spotting Comet Tsuchinshan-ATLAS between twilight’s end and moonrise. The comet should be about 4th magnitude now, much faded from a week ago. But the dark sky helps make up for this, especially for time-exposure photography. And with the comet now nice and high in the southwest, it’s a great time to examine its head and nucleus at high power for changing night-to-night details. The Moon will rise nearly an hour later each night from now on.

■ After the Moon does rise tonight, watch for Jupiter to rise to its lower right 30 or 40 minutes later. They’ll accompany each other across the sky until dawn.

MONDAY, OCTOBER 21

■ Now that it’s late October, Deneb has pushed Vega toward the west and has taken its place as the zenith star during the last of twilight (for skywatchers at mid-northern latitudes).

TUESDAY, OCTOBER 22

■ The Moon, nearly last quarter, rises around 10 or 11 tonight. Give it a while to rise higher, and it forms a nice triangle with Castor to its left and Pollux to its lower left. Farther below the Moon, Mars is coming up.

By the dawn of Wednesday the 23rd, the four of them are grouped very high in the south as shown below.

It’s only October, but by early dawn Gemini is high in the south — the evening stance it assumes in March.

WEDNESDAY, OCTOBER 23

■ The last-quarter Moon rises around 11 or midnight tonight. Forming a gently curving arc above it are Castor, Pollux and Mars, in that order from top down. That’s also their order of increasing brightness. The arc is 10° long. By dawn on the 24th the pattern has twisted clockwise, as shown above.

THURSDAY, OCTOBER 24

■ The Ghost of Summer Suns. Halloween is approaching, and this means that Arcturus, the star sparkling low in the west-northwest in twilight, is taking on its role as “the Ghost of Summer Suns.” For several evenings centered on October 25th every year, Arcturus occupies a special place above your local landscape. It closely marks the spot where the Sun stood at the same time, by the clock, during hot June and July — in broad daylight, of course!

FRIDAY, OCTOBER 25

■ Venus is in conjunction with orange Antares low in twilight, as shown below. Venus is 100 times brighter than Antares; look for the tiny orange point 3° to Venus’s lower left. Binoculars will help you spot it through the twilight and the thick air near the horizon.

A moderately wide miss: Venus and Antares are in conjunction, 3° apart.

SATURDAY, OCTOBER 26

■ Spot bright Altair high in the southwest soon after dark. Brighter Vega is far to its right.

SUNDAY, OCTOBER 27

■ Draw a line from Altair, the brightest star very high in the southwest after dark, to the right to Vega, very high in the west and even brighter. Continue the line onward by half as far, and you hit the Lozenge: the pointy-nosed head of Draco, the Dragon. Its brightest star is orange Eltanin, the tip of the Dragon’s nose, always pointing toward Vega.

This Week’s Planet Roundup

Venus, magnitude –4.0, gleams low in the southwest as evening twilight fades. It continues to set around twilight’s end.

Jupiter (magnitude –2.6, still near the horntip stars of Taurus) rises in the east-northeast around 9 p.m. Like Mars, it’s highest in the hours before dawn. Jupiter is now a nice 45 arcseconds wide in a telescope, hardly smaller than the 48-arcsecond width it will attain for the weeks around its opposition in December.

  Oct. 20-27: Jupiter optimal for telescope viewing, The Sky