On Tuesday evening, April 8, you can experience one of the most beautiful events the sky can deliver. Head outside no later than an hour or so after sunset (around 8:30 P.M. local daylight time) and look to the west. Your eyes should land immediately on the slender crescent Moon, oriented with its cusps standing nearly straight up from the horizon. Point your binoculars at the Moon to reveal a stunning sight: the bright Pleiades star cluster (M45...

If you've been watching the Moon after sunset this week, you may have noticed it lies lower in the sky than usual (at least if you live at mid-northern latitudes). It's not your imagination — the Moon is figuratively scraping the treetops this week. Although this is no great mystery, it never hurts to remind yourself about the Moon's monthly and yearly cycles. The Moon's maximum altitude from any given location depends on its declination...

I recently returned from a 9-day trip to Chile — one of more than 30 participants in a tour sponsored by Astronomy magazine and organized by MWT Associates. We all had a great time, despite long plane rides from the States down to Santiago. Our two main reasons for going were to experience the clear skies of the Atacama Desert and the giant telescopes at Cerro Tololo Interamerican Observatory, but plenty of other sites kept us busy. Last week I wrote...