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


Photo of the Week. A panorama featuring northern Scorpius with Antares at lower left, Libra at center, and eastern Virgo with Spica at upper right. See a labelled view.

Astronomy news for the week starting Friday, July 3, 2009.

Happy Birthday USA. The Moon celebrates by starting off in its waxing gibbous phase, then passing full the night of Tuesday, July 7, when it will undergo a penumbral eclipse that peaks at 4:38 AM CDT. Don't expect any grand sight, or for that matter of even think of getting up to look. The Moon will just clip the outskirts of the partial shadow of the Earth. If you were standing on the Moon, you would see the Earth take a just small bite off the edge of the Sun. The amount of light lost is minimal, and the effect on the Moon as seen from here is about zero. Following full, the Moon then enters its waning gibbous as it heads towards third quarter, that phase not reached until next week.

It'll be a far better sight to watch the waxing gibbous plow through Scorpius. Look the night of Friday the 3rd to see the Moon just to the right of bright reddish Antares. By the following night, the Moon will have shifted to the other side, appearing above the curve of the Scorpion's tail. In between the Moon will occult the star as viewed from Japan to Hawaii.

The night of Thursday the 9th, the Moon will then lie to the northwest of Jupiter, which now rises around 10:30 PM Daylight Time just as formal twilight comes to an end. Before that, you can admire Saturn, which will grace the western sky in Leo until it sets about an hour after Jupiter rises.

The morning sky is now the domain of Mars and Venus, much fainter Mars rising around 2:30 AM, brilliant Venus about half an hour later. Both planets are now making their way through Taurus, beautifully placed to the west of the Hyades Cluster and south of the beloved Pleiades.

Most likely, however, the biggest news involves us, the Earth, as our planet passes aphelion the evening of Friday, July 3, when we will be farthest from the Sun for the year, at a distance of 147.1 million kilometers (91.4 million miles), 1.7 percent farther than average. Given the heat of the day, it's clear that the solar distance has nothing to do with the seasons, but everything to do with the 23.4 degree tilt of the rotation axis against the orbital axis.

Follow the curve of the Big Dipper's handle south first to Arcturus in Bootes and then to Spica, the centerpiece of the otherwise dim constellation of Virgo, the Maiden. This blue first magnitude star ranks 16th in the list of brightness and anchors the rest of the constellation, which sprawls broadly to the northeast and northwest.
Valid HTML 4.0!