Skylights featured on Astronomy Picture of the Day

Scout Report Selection Webivore Selection SpaceCareers Selection

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


Photo of the Week.. Winds aloft blow streaming horsetails from high cirrus clouds set before a stunning blue sky.

Astronomy news for the two week period starting Friday, September 12, 2003.

Skylights is also presented a day early, and will return on Saturday, September 27.

During this extended period, the Moon passes two phases "of the moment." Beginning in its waning gibbous phase, it passes third quarter on Thursday, the 18th, about the time of Moonset in North America. Near the Summer Solstice, and at the same time swinging north of the ecliptic on its tilted orbit, this third quarter will be the highest of the year, our companion nicely set in eastern Taurus. Waning through crescent, the Moon will then pass its new phase on Thursday, the 25th.

As the Moon orbits, it will pass north of Saturn the night of Friday the 19th (shortly before Saturn rises, which it does around local midnight, 1 AM Daylight Time) and then north of Jupiter the night of Tuesday, the 23rd, again before the planet rises. The morning of the 20th, the Moon will reside to the northeast of Saturn. The morning of the 23rd find the thinning crescent beautifully placed in twilight in Leo above rising Jupiter. The morning of Wednesday, the 24th, the even thinner crescent will be situated more or less between Jupiter and Mercury, the latter making a very nice appearance for us. The little planet will reach its greatest western elongation on Friday, the 26th, when it is 18 degrees to the west of the rising Sun.

Of all the planets, Mars of course still dominates, as it shines brilliantly among the faint stars of Aquarius. Look directly below the red planet as it climbs the southeastern sky in early evening to find the star Fomalhaut in Pisces Austrinus, the "Southern Fish."

However, it is planet Earth that makes the biggest splash. At 5:47 AM Central Daylight Time (6:47 Eastern, 3:47 Pacific), the Sun will pass the autumnal equinox in Virgo. Astronomical fall will then commence in the northern hemisphere, spring in the southern. At that moment, the Earth's axis will be perpendicular to the line to the Sun, the Sun will be on the celestial equator, will rise due east, set due west, be up for 12 hours, and down for the same. (The extended solar disk and refraction by the Earth's atmosphere, which raises the Sun somewhat from its real position, actually causes the day to be a few minutes longer than the night). People at the Earth's equator will see the Sun pass through the zenith (the overhead point). The Sun also formally sets at the north pole, and finally rises at the south pole (though again solar diameter and refraction make the Sun linger a bit at the north pole, and rise a bit early at the south).

With autumn making its debut, the summer constellations are near the meridian at sunset (admire Sagittarius now and its Little Milk Dipper while you have the chance), and the fall constellations make their bid for attention. Watch the rising of the Great Square of Pegasus, and see the "W" of Cassiopeia climb the northeastern sky.
Valid HTML 4.0!