Clustered at Horizon’s Edge

By J. Alex Knoll

The sun sets this week around 8:10. Following the trail of the sun, look above the northwest horizon for golden Capella, the sixth-brightest star. Opposite, in the northwest, shines Vega, the fifth brightest star. This time each year, the two line up at the same height in the sky, right now around 10pm.
    Friday, the waxing moon shines 10 degrees below Saturn. The ringed planet appears high in the southeast at sunset. By midnight it hovers in the southwest before finally setting in the west around 4:30am.
    Saturday, the moon shifts a dozen degrees to the lower left of Saturn. But just a few degrees above the moon shines the first-magnitude star Spica, actually a little brighter than Saturn.
    By Monday the moon leaves Saturn and Spica far behind and is amid the constellation Libra. While its stars are only modest, its second-brightest, Zubeneschamali, a dozen degrees north of the moon, is the only green-hued star visible to the unaided eye.
    Tuesday, the full moon rises in the southeast before 9pm. Trailing just a few degrees behind is the red-giant Antares, the heart of Scorpius.
    The best sight in the night skies is actually before the break of day. If you’re up an hour before sunrise, this week around 5:55am, look above the east horizon for the bright glow of Venus, whose light is unrivaled by anything except the sun and moon.
    As bright as Venus is, you’ll likely need binoculars to spot her. And you will certainly need them to distinguish the three other planets — Jupiter, Mercury and Mars — clustered tightly together all within just a few degrees of one another.
    Jupiter, the next brightest, is closest to Venus at week’s end before pulling up and away. Much-fainter Mercury is to the lower left of its brighter neighbors. Mars is the dimmest of the bunch but rises earlier and climbs higher in coming days.