April 2000

by Steve Stefanik

As the month of April begins a trio of planets, Saturn, Jupiter, and Mars, will appear low in the western sky as the sun sets. Most likely you’ll spot Jupiter first because it is the biggest and brightest at -2.0 magnitude. Saturn, the second largest planet and so the second brightest of the trio at magnitude +0.3, will be positioned about 5 degrees higher and to the left of Jupiter. Mars, tiny in comparison to the other two, will be the dimmmest at magnitude +1.5 and most difficult to spot. Look for it about 2.5 degrees lower and to the right of Jupiter. During the first week of this month Saturn and Jupiter will be inching lower and lower toward the western horizon while Mars will be moving eastward toward the two. On the evening of April 6, Mars will be within 1 degree of Jupiter. On the successive evenings of April 5-7 a slim crescent moon will slide by each of the planets. On the evening of the 11th the three will form a tight triangle 3 degrees from each other. This will be the closest they appear to each other for the next 20 years until March 26, 2020. From April 13-15 they will remain within 3 degrees of one another and on the night of the 16th Mars will finally slip past Saturn within 2.5 degrees of it. By April 30th, Mars will appear 12 degrees higher than Jupiter and Jupiter will be 3 degrees below Saturn. By the end of the month Jupiter will set about half an hour after the sun sets followed by Saturn 10 minutes later. Mars will linger above the western horizon for another 90 minutes.

Uranus and Neptune are now rising in the middle of the night in the constellation Capricornus but you’ll need a telescope to spot them.

The only other planets to be seen are Venus and Mercury but they appear low on the eastern horizon before dawn. Venus will be the easier of the two to spot because of its -3.9 magnitude brilliance. Mercury will be positioned higher and to the left of Venus but it will be considerably more difficult to spot because of its much dimmer +0.2 magnitude.

The New Moon occurs on the night of April 4th and the Full Moon will occur on the night of the 18th. Easter, which occurs the first sunday after the first Full Moon after the Vernal Equinox will be celebrated on April 23rd this year.