Mar 30

What’s Up in the Sky

What’s Up in the Sky – April, 2020

A Great Month Ahead

I am excited about the coming month. Not only will there be some very nice observing opportunities and historic events to remember, but an event of great personal significance will occur, one which I plan to observe.

April will start off with a real bang, easily visible in the western sky after sunset. I am sure most readers have noticed the planet Venus shining like a beacon out over the lake after sunset. Next week observers will be treated to a spectacular display of orbital mechanics as Venus appears to pass through the Pleiades star cluster. Although it will be visible to the naked eye, binoculars will give you a better view of the planet passing close to individual stars in the cluster. A telescope aimed at the scene will allow you to witness the movement of the planet against the background star cluster. It promises to be a rare and beautiful sight!

Conjunctions of Venus and the Pleiades occur every year at this time, but rarely does the planet appear to pass through the cluster. However, every eight years nearly to the day, the planet crashes the party and becomes the brightest member of the group.

You can begin observing this event right away by watching each night as the planet inches closer and closer to the cluster. On April 3, Venus will be with the seven sisters for their eight year reunion. Don’t miss it. Even if the weather does not cooperate, don’t give up. This reunion will be visible all week and even one sighting will be worth it.

The following week the Moon may be seen passing close to the planets Jupiter, Saturn, and Mars. Unfortunately, you have to be up before sunrise to witness this event, easily visible low in the southeast.

Between these events, on April 7, will be a Supermoon – a full moon that occurs when the Moon is at the point in its orbit where it is closest to Earth, causing it to appear larger than usual. Although this phenomenon gets a lot of press, you really won’t notice it being any larger than usual unless you could view a side by side comparison with October’s full Moon.

At the end of this column you can see that April is an historic month for space exploration. I have always found it interesting that the first person in space and the first Shuttle launch occurred exactly twenty years apart and you can also see that this is the thirty year anniversary of the Hubble Space Telescope’s launch. But this month marks forty one years since one of my first, and greatest, astronomical observations.

You may have noticed the Moon, Venus, and the Pleiades forming a lovely triangle last night. On Saturday, April 25, the Moon will also have a close encounter with the bright star Aldebaran. A similar event occurred on Saturday, April 28, 1979, only that time, the Moon actually occulted (passed in front of) Aldebaran, blocking the star from view.

On that date, my wife and I were driving to Kalamazoo for a gathering of friends. It was a clear evening so, as Lyne drove, I watched Aldebaran approach the Moon’s unlit edge. I knew the occultation would happen soon, so when we arrived I told everyone to come outside and see it. Only one other person joined me.

It was the end of twilight with a crescent Moon. We both thought we would see the star fade out and disappear but instead, BAM! it was gone! Both of us were not only amazed at what a tremendous sight it was but also astonished that we were the only witnesses. When we tried to share our amazement with the others we got comments like, “. . . what’s the big deal, doesn’t that happen every night?”

Actually, no, it doesn’t. It may seem like the Moon should pass by many stars on its nightly journey through the sky, but actually, the stars are basically moving with it and most are not in its path. So occultations such as that one are extremely rare and when you consider timing, weather, and conflicting activities, it turns out to be one of the rarest of sights one can witness up in the sky.

This month in history:
April 01: Comet Hale-Bopp nearest Sun – 1997
April 02: First photograph of Sun taken – 1845
April 12: Yuri Gagarin becomes first human in space – 1961
April 12: Columbia is first space shuttle to be launched – 1981
April 17: Apollo 13 returns to Earth – 1970
April 25: Deployment of Hubble Space Telescope – 1990
April 28: Eugene Shoemaker is born – 1928