Skylights featured on Astronomy Picture of the Day

Scout Report Selection Webivore Selection SpaceCareers Selection

Skylights featured nine times on Earth Science Picture of the Day: 1 2 3 4 5 6 7 8 9 -- Full List Restored!


Photo of the Week. A new day.

Astronomy news for the week starting Friday, April 6, 2012.

We start off the week with the ever-popular (except for those wishing dark skies) full Moon, which takes place during the day on Friday, April 6, such that it will rise just past the phase that evening. The Moon thereafter fades in the waning gibbous phase (cheering the dark sky folks) until it hits last (third) quarter the morning of Friday the 13th with the Moon high in the sky at dawn. The night of the 6th, look for the Moon to be just to the southwest of Saturn, with Spica in between, the brightness of the lunar disk making the star hard to spot. At about the same time, the Moon is going through perigee, where it is closest to the Earth.

Venus, which is commonly taken for a UFO, continues its show, not setting until 11:30 PM Daylight Time (providing of course that you have a good, flat horizon). Its planetary brilliance unmatched, it will continue to brighten throughout the month. Its mate in bright "UFO-dom," Jupiter, has now sunk rather far down from Venus and is now setting by 9:30 PM, just half an hour after the end of formal twilight, so look early. But all is not lost. Just half an hour or so after the giant planet goes down, very bright orangy Mars transits the meridian high to the south to the east of Regulus in Leo. Note the contrast between the "red planet" and the white, even blue-white, star. Saturn, rising just after sunset, spends its evening and early-morning time in the east, rising ever higher until it transits the north-south line just after local midnight (1 AM Daylight Time).

For all the planetary show-offs, the week actually belongs more to the minor bodies of the Solar System. The fourth-discovered of the asteroids, Vesta, the only one visible to the naked eye, goes through conjunction with the Sun on Monday the 9th, while far more famed Pluto begins its retrograde (westerly) motion the next day amidst the myriad stars of northern Sagittarius. Taking some 238 years to orbit the Sun at an average distance of 39 Astronomical Units (the Earth-Sun distance), the small (dwarf?) planet seems hardly to move at all. But on the morning of Thursday the 12th, the little one, about the size of the western US, gets hit with the passing Moon, which actually occults the planet as seen from Antarctica (the event then doubly invisible).

This is the time of year for Leo, the Nemean Lion of Hercules' fame, which by 9 PM is approaching the meridian, holding very bright Mars, eminently recognizable by its distinctive "Sickle" that ends in Regulus. To the south lie dim modern Sextans (the Sextant) and ancient Crater (the Cup), which fall on the back of Hydra (the Water Serpent).
Valid HTML 4.0!