Skylights featured on Astronomy Picture of the Day

Scout Report Selection Webivore Selection SpaceCareers Selection

Skylights featured four times on Earth Science Picture of the Day: 1 , 2 , 3 , 4 .

Cassiopeia and Perseus

Photo of the Week.. As spring comes on, Cassiopeia and Perseus leave a reminder of fall and winter, the Milky stretching between the two, the Double Cluster right in the middle.

Astronomy news for the short week starting Sunday, March 30, 2003.

The next Skylights will appear on Friday, April 4.

It is the week of the new Moon, when the skies are dark all night, allowing us to see the stars in all their glory, the phase taking place on Tuesday, April 1 (no April Fool here, it really does). Observational astronomers divide themselves into two groups, one that requires "dark time" between third and first quarter, and the "bright time" people, whose work is not hampered by moonlight. First and third quarters by themselves (and the couple days around them) are aptly referred to as "grey time." Northern hemisphere Spring is the time that dark time astronomers most emerge, as the Milky Way lies on the horizon, allowing them a view perpendicular to the Galaxy's dusty plane to see the realm of the galaxies, Virgo, Leo, Ursa Major, and Coma Berenices filled with them.

Two days after new, the Moon passes its apogee point, where it is farthest from the Earth, a distinctly uneventful event. The waxing crescent will become barely visible the night of Wednesday, April 2, when it will be just to the left of Mercury, which is growing out of bright evening twilight. The night of Thursday, the 3rd, the Moon will be far better visible, with earthlight illuminating its nighttime side.

Though Venus is still with us as the "morning star," it is notably lower in the southeast, now rising after the break of dawn. In the evening sky, Saturn goes to the other limit. Now well west of the meridian as the sky grows dark, the planet sets around midnight. Two planets are in the middle. Growing brighter in the morning southeast, Mars rises around 2 AM, while Jupiter, which quite dominates evening skies, is high in the south at the end of twilight, and does not set until after Mars rises.

April is time for Orion's leaving, that icon of the winter sky now well to the west at sunset. Now it is time to admire the icon of spring, the Big Dipper, which is high in the northern sky by 10 PM. South of the Dipper lies Leo, while farther to the south sprawls the longest constellation in the sky, Hydra, the sea serpent. On its back ride three constellations, dim modern Sextans, the Sextant, also- dim but ancient Crater, the Cup, and quite prominent Corvus, the Crow, its two upper stars pointing eastward to Spica in Virgo. Hydra spills from the northwest to the southeast. At one time the 26,000 precessional wobble of the Earth's axis had it resting close to the celestial equator.
Valid HTML 4.0!