Let's go for a dip in the old mail bag again shall we. Well, not really the mail bag, someone on my Facebook page asked what has been causing all these planetary and planet/moon conjunctions that I have been talking about.
Good question. There is an imaginary line that runs around Earth called the equator. It divides the northern and southern hemispheres.
Just as Earth has a line around the middle, so does our sun. If the solar equator is extended into space it marks the plane where all the planets will generally have their orbit.
This line is called the ecliptic and is the place where generally all the planets will be found at some time during the year. It is also the path the sun follows against the background of the stars as seen from Earth.
This line also is the location of the zodiacal constellations
The moon also follows this line thus allowing it to join the planetary party at various times during the year.
The planets really only appear close. In reality we are looking at them along the same line of sight.
Venus, located between us and the sun, is an average of 67 million miles from the sun. Jupiter, on the other hand is the fifth planet out from the sun and is an average of 483 million miles from the sun.
The same can be said for Mercury and Uranus which were in conjunction a couple of weeks ago. Mercury is the closest planet to the sun and Uranus is out beyond the orbit of Saturn and their close appearance was again along the same line of sight.
When the moon joins the party it is just passing between us and the planets in the same general vicinity. But, because its orbit is along the ecliptic it can appear to look close.
Venus and Jupiter were at their closest yesterday. Venus will continue to rise higher after sunset and the pair, although drawing apart, will appear close for the next couple of weeks.
If you want to see a really nice conjunction, wait until April 2-3 when Venus will invade the Pleiades star cluster and play an April Fool joke on all of us by appearing to be right in the cluster. More about that later.
I have been hearing a lot of people say they are ready for spring. Well, sports fans, spring is about to be sprung.
Officially the vernal (spring) equinox is at 1:15 a.m. EDT on Tuesday, March 20 when the sun crossed the equator moving north. But for us folks here in the Mountain Time Zone, that makes it 11:15 p.m. on Monday, March 19.
That will give us a couple of hours jump on the rest of the country -- except for the people in the Pacific Time Zone who will get an hour jump on us.
Anyway, as my dear sainted grandmother used to say, "Spring has sprung, the grass is riz, I wonder where the flowers is."
SKY WATCH: Third quarter moon yesterday, Wednesday, March 14. Jupiter and Venus are still in fairly close conjunction. Look east about an hour after sunset for a bright Mars in the east. It is just below the middle of Leo, the Lion. Orion, the King of Winter has moved into the western part of the sky and, typically for spring, the Big Dipper asterism is almost upside down in the northeast after sunset symbolically pouring out the spring showers.
NEXT WEEK: More astronomical blathering.