During one of my recent night sky tours, a curious young lady asked if I was excited about the planets lining up this week. My answer was a succinct “no.”
I’m pretty sure that caught her off guard. I mean, who could not be excited by such a rare and significant celestial event, especially someone who studies the heavens for a living?
I explained that the planets have been in “a line” across the sky every night for the past 5 billion years.
That “line,” or arc, is called the ecliptic, and it defines the geometric plane of our solar system.
It is roughly along this path that the planets, sun and moon all appear to move. If ever you see a planet not on that arc, call me! Immediately!
No, what interests me more is that we can see all the planets together in the same part of the sky.
It occurs for the same reason that all cars in an auto race appear to bunch up on one side of the track from time to time before spreading out once again.
By late spring, only Mars, Jupiter and Uranus will lie in our evening sky; the remaining planets will appear only in the early morning sky — but still along the same arc.
This week, however, we have a chance to see all the planets of our solar system shortly after sunset. Venus, Mars and Jupiter shine brightly in our sky and are hard to miss, and the Earth … well, it’s pretty hard to miss as well!
To see Mercury and Saturn you must have a very low horizon with a clear sky to the west because they’re tough to spot in the glow of sunset. In fact, you may need binoculars to find them at all.
These two worlds will change their relative positions over only a few days.
Early in the week, look for Saturn just above and to the left of brighter Mercury. On Feb. 24, the two will lie nearest each other in the sky and almost parallel to the horizon.
Of course, this is an illusion only, since Mercury lies only 112 million miles from us while Saturn is nearly a billion miles away.
After that, Saturn will drop farther below Mercury and within a few days will become invisible against the glow of sunset.
Uranus and Neptune are the farthest and faintest planets and, as such, require a telescope to see at all.
Only if you know where to aim it and have patience sorting through the starlike points of light in your field of view will you be able to identify these distant worlds, but it’s certainly worth the effort.
By Feb. 28, the thin crescent moon will appear between Mercury and Saturn, something that binoculars will be needed to see.
But after that, the moon will continue along its monthly orbit around the Earth and will move eastward along the ecliptic.
Look for it to pass by Venus on March 1, Jupiter on March 5 and 6, and Mars on March 8.
I wish you clear skies for a fun week of planet gazing!
