This column was provided by San Benito County resident and amateur astronomer David Baumgartner as part of a local series on astronomy.
I would imagine most of us have gazed up at the night sky and noticed how the stars seem to be somewhat stationary. Actually they are moving quite fast. We don’t notice their movement because of their vast distance from us. If you could go back in time, say a few thousand years, and compare the star formation then to our skies today, you would have a hard time picking out your favorite constellation. You would notice that some of the stars have moved quite a bit, mainly because of their closeness to us. The farther away the stars are from us the less movement you will notice.
As you spend more time viewing the havens you will eventually notice that one of these stationary stars has movement than the rest. This would most likely be a planet.
From our point of view on Earth, other planets seem to wander about in the sky. Early astronomers first referred to the planets as ‘Wandering stars’ because of the way they moved in the night sky far more quickly than the fixed stars. Of course, we know that though to the untrained eye, these wandering stars may appear as small pinpricks of light, they are in fact planetary bodies in our own solar system.
So you are probably wondering by now, that it looks like Mr. Baumgartner has gone off track again. Maybe distracted by a butterfly passing by or just another thought going through his mind. For what does this have anything to do with a conjunction? Good point, I must say.
What is a planetary conjunction anyway? In astronomy, a conjunction occurs when any two astronomical objects (such as asteroid, moons, planets, and stars) appear to be close together in the sky, as observed from Earth. Occasionally planets seem to occupy the same space in the night sky because of their alignment, though they are in fact millions of miles away from each other. This would be considered a planetary conjunction.
Usually, the distance between objects during a conjunction varies from 0.5 degrees to 9 degrees. To understand it better, imagine that 0.5 degrees is the average width of a Full Moon disk. Sometimes planets come even closer. The last time it happened with Jupiter and Saturn in 2020 when they appeared less than 0.1 degrees apart. Such an event is called the great conjunction and provides a spectacular show for stargazers.
Sometimes people confuse a planetary conjunction and a planetary alignment, sometimes referred to as a planet parade. A conjunction implies a shorter than usual distanced between objects in the sky, while an alignment means that planets line up in a row in the same area of the sky, as seen from Earth.
On March 1 at 3:15 p.m. Venus (magnitude -4) will met with Jupiter (magnitude -2.1) in the constellation Pisces at a distance of 29’ 24”. This was observable through a telescope or binoculars as well as with the naked eye.
On March 28 Mercury passes 1.5 degrees north of Jupiter at 8 p.m. And on March 30th Venus passes 1.3 degrees north of Uranus at 11 p.m. They are all considered planetary conjunctions.
Conjunctions may not be the most exciting events in the night sky, but just like anything else up there shinning back at us, sometimes it’s just the fact that we know it’s going to happen, and we know where and how to find it.
Clear skies…..
Constellation of the month
SEXTANS
Sextans is located in a dim region of the sky between the constellations Hydra, which we covered last month, Carter, and Leo. The constellation was created by the Polish astronomer Johannes Hevelius in the 17th century. It is a rather faint one, with only one star brighter than fifth magnitude. Sextans is the 47th constellation in size and is one of the 15 equatorial constellations.
Sextans contains several notable deep sky objects, among them the Spindle, and spiral, galaxies, and Sextans A and B galaxies.
Sextans is not associated with any myths, like last month. So no long stories from the Gods this go round.
So let’s see how good you are with your night sky know how. Have a go at it and see if you can find ite.
What’s up this month?
Mar 07: Full Moon
Mar 14: Last Quarter Moon
Mar 19: Moon passes 4° south of Saturn
Mar 19: Moon is at perigee (225,369 miles from Earth)
Mar 20: Vernal equinox occurs at 2:24 p.m.
Mar 21: New Moon
Mar 22: Moon passes 0.5° south of Jupiter
Mar 24: Moon passes 0.1° south of Venus
Mar 24: Moon passes 1.5° noth of Uranus
Mar 28: Moon passes 2° north of Mars
Mar 28: Mercury passes 1.5° north of Jupiter
Mar 28: First Quarter Moon
Mar 31: Venus passes 1.3° north of Uranus
Mar 31: Moon is at apogee (251,605 miles from Earth