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 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
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.