Photo of the Week. The full Moon displays its
maria, dark lava flows that fill or flood out from ancient
impact basins and make the "Man in the Moon." Learn their names.
Astronomy news for the week starting Friday, March 30, 2007.
'Tis the week of the full Moon. Preceded
by a few days of the waxing gibbous,
full phase is reached during the day on Monday, April 2, so it will
rise just past full that night, and therefore just after sundown.
The remainder of the week sees it waning in the gibbous phase toward third
quarter, which does not take place until next week. The
traditional names of the April full Moon -- Grass Moon, Egg Moon,
Planter's Moon -- reflect the warming of days under the spring Sun. As the Sun climbs higher
to the north, the full Moon drops lower to the south, this one
taking place in Virgo. Watch for
it the night of Monday the 2nd just to the west of Spica. Less than a day after full
phase, the Moon passes apogee,
where it is farthest from the Earth.
While
Venus climbs ever higher into each western evening sky, Saturn
shifts more and more in the opposite direction. Not setting
until 10:30 Daylight Time, the second planet from the Sun quite
rules early-to-mid-evening. Almost an hour before Venus sets, you
can find the ringed planet to the south between Leo and Cancer and to the west of Regulus.
Jupiter now makes two transitions, first by beginning to rise
before local midnight (1 AM Daylight) as it formally moves into the
evening sky; second by ceasing its normal easterly motion against
the stars on Thursday the 5th and beginning this year's
retrograde (westerly) motion as the Earth prepares to swing
between it and the Sun. Antares,
to the southwest of the giant planet, will provide a fine marker
against which to see Jupiter's increasing motion, much as Regulus
now does for Saturn. A few days earlier, on Friday the 30th, Pluto, in extreme northwestern
Sagittarius and not that far from
Jupiter (at least in angle, but almost six times farther away),
enters retrograde as well. To finish things off,
Mercury (in bright morning twilight) passes conjunction with Uranus
on Sunday the 1st, while the rising of Mars still tracks the
cracking of dawn.
Three pairs of constellations come
in major and minor forms. The best known are ancient Canis Major/Minor (Big and Small Dogs) and Ursa Major/Minor (Big
and Small Bears). These are so prominent that we little note Leo and Leo Minor, the Big and Small Lions, the little one
faintly riding the back of the big one. Look for it roughly
between Leo the pairs of stars that make the feet of Ursa Major.
