SKYLIGHTS

Astronomy news for the week starting Friday, March 9, 2001.

We start the week with the full Moon, with the full illuminated hemisphere of the Moon is visible to us on Earth, which reveals the great extent of the dark lunar maria. They are huge lava-filled impact basins that make the face of the "man in the Moon," and are three to four billion years old. They reveal the awesome violence of the early Solar System, of the time when the planets were sweeping up the debris of the smaller bodies of which they were made. The Moon then spends the rest of the week waning through its gibbous phase toward third quarter, which will be reached next Friday the 16th.

The morning of Thursday, 15th, the Moon will appear just to the west of Mars, the morning of Friday the 16th to the east of it. The red planet is now passing far (about 10 degrees) to the south of much more distant Pluto. While Mars invades Scorpius (and is now to the northeast of its namesake Antares), Pluto, because of its highly tilted orbit, lies among the stars of southern Ophiuchus. Mars now rises shortly before 1 AM. Staying up until dawn may afford a view of Mercury, which reaches greatest western elongation, a whopping (for Mercury) 28 degrees from the Sun. However, the northern hemisphere morning ecliptic this time of year lies relatively flat against the horizon, so Mercury will still be difficult to glimpse in eastern morning twilight. The view is far better from the southern hemisphere. The little planet will pass only a tenth of a degree north of Uranus the morning of Saturday the 10th.

The planetary view in the evening is much better. While Venus now descends the evening sky, it is still glorious in western twilight. Farther east in Taurus, Jupiter and Saturn linger in the sky through nearly the entire evening, the pair finally setting shortly before midnight.

Taurus, with its marvelous Pleiades -- Seven Sisters -- star cluster is the southern figure of a triangle of bright constellations. To the northwest is Perseus, whose central region is also made of a star cluster. To the northeast is Auriga, the Charioteer, to which Taurus is actually connected through its northern "horn" (one star part of both constellations) and which contains the sky's sixth brightest (and most northerly first magnitude) star Capella. All three are set into the Milky Way, that fainter part of the Milky circle that is formed by the outer part of the Galaxy. Perseus is filled with numerous bright hot high mass stars from episodes of recent star formation, while Taurus and Auriga are filled with thick dark clouds of dust in which stars are now vigorously being born.