SKYLIGHTS

Skylights featured on Astronomy Picture of the Day

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

Orion

Photo of the Week.Goodbye Orion.


Astronomy news for the week starting Friday, April 24, 2009.


The Moon begins our week, Friday, April 24, right in its new phase. The whole week is then devoted to evening's waxing crescent, the Moon not passing first quarter until the afternoon of Friday, May 1, when it can be seen rising in North America. The timing is such that you might be able to spot an especially thin crescent in evening twilight the night of Saturday the 25th. By the following night, the sight will be vastly better, and then the whole waxing affair becomes totally obvious. Be sure to look for earthlight (light reflected from Earth) on the nighttime side of the Moon, allowing you to see the whole lunar disk. As the lunar phase grows, someone on the Moon would see a waning Earth, and earthlight fades away.

The night of Sunday the 26th, the Moon will lie in a wonderful position just above the Pleiades star cluster, both of them in turn lying just above the planet Mercury, which is making fine showing this week, as it passes greatest eastern elongation with respect to the Sun the previous night. The following evening, that of Monday the 27th, the Moon will have moved to a higher position between the Taurus's Hyades and (farther up) the star Elnath (Beta Tauri).

The end of the week sees another "cross quarter day," this one around April 30-May 1 (May Day), when we are halfway between the beginning of spring and the start of summer. With the Sun halfway between the vernal equinox and the summer solstice, the crescent will be heading toward its first quarter position in southwestern Gemini. The evening also brings us Saturn. Idling in southeastern Leo, Saturn crosses the meridian to the south just after the end of formal twilight around 9:45 PM Daylight Time, which is about the time Mercury sets. The ringed planet is then with us nearly all night, setting about the time Venus rises in the east, near the beginning of morning twilight, 4:30 or so AM. By that time, Jupiter is well up in the southeast in a setting among the faint stars of northeastern Capricornus.

In late evening, then cast your eyes nearly overhead (for the temperate northern hemisphere) to admire Ursa Major's Big Dipper. To the south toward Leo and Cancer, you'll find three pairs of stars that the ancient Arabs saw as the "leaps" of the gazelle.
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