Five Planets


(This column was first published in the May 6, 2002 Buffalo News.)


The mnemonic "Men Very Easily Make Jolly SUN Possible" may not make much sense and is even a bit sexist, but it does help if you wish to memorize the nine planets in their order of distance from the sun.* The capitalized letters represent: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.


The list plays another role as well. The first four planets on it are called terrestrial planets because of their rocky, metallic, earth-like composition and the next four from Jupiter to Neptune are called giant, Jovian or gas planets because of their size, their similarity to Jupiter and their make-up almost entirely of gasses. (It has been said that Saturn is so light that an object of its density would float on water.)


Sensible or not, that list leads me to the subject of today's column. The first five of those planets (not counting Earth) are currently in view in our evening sky and tonight four of them will be clustered so close that you could hide them all behind your thumb held out at arm's length. More to the point, if you look at them through binoculars, you should be able to fit those four planets in a single view.


Weather permitting, shortly after 9:00 this evening, you will find Venus, the brightest object in the sky, near the northeastern horizon. It will appear above where the sun set at about 8:20. There is a reason for this follow-the-leader progression. The sun and the planets of our solar system revolving around it are all in or near the same plane in space. Thus we see all of these heavenly bodies apparently traveling along the same line through the night sky. That line is called the ecliptic.


Very close to Venus will be Mars and Saturn and slightly below them, Mercury. These three planets will be not nearly as bright as Venus and you may at first confuse the nearby star Aldebaran for one of them. Aldebaran will be slightly south of Mercury along the horizon. To differentiate stars and planets, recall that stars twinkle and planets, which only reflect the sun's light, do not. Through binoculars you should also note the red color of Mars and the yellow of Saturn.


Only Jupiter will be at a distance farther along the ecliptic. It will be almost half way up from the western horizon toward the zenith. You should be able to pick it out, however, as it will appear quite bright, not as bright as Venus, but brighter at this time than the brightest star visible in the night sky.


That brightest star, Sirius, you should also be able to see near the horizon but in the southwest. Often called the dog star, it is part of the constellation Canis Major, most of which will be below the horizon.


Midway between Sirius and the planets near Venus you will find the three stars that make up Orion's belt and above them, Betelgeuse, one of the two bright stars in this constellation. The other, Rigel, will be below the horizon. I don't know who came up with the jawbreaking names for the stars in Orion's belt -- Alnitak, Alnilam and Mintaka -- but they certainly set a challenge to rapid pronunciation.


The planets will all remain in view for about another ten days. It is important, however, that you look for them early in the evening as they begin to follow the sun below the horizon at about 10:00 p.m. Between May 13 and 15, the waning crescent moon will join this spectacular parade.-- Gerry Rising

* Several alternate (and usually better mnemonics have been offered by readers: