Newsletter Archive

The Two Brightest Planets

April 30, 2022


Hello, Stargazers!

Just as a reminder, you're receiving this newsletter because you signed up for it on my "Astronomy For Thinkers" website. I've been taking a break from astronomy while I focus on math for a while, so this is my first newsletter issue in a few months. In this issue, I wanted to give a brief update on what I'm up to, and to point out the beautiful scenery currently in the morning skies.

I also want to remind you about the upcoming lunar eclipse, but I'll send a separate newsletter describing the eclipse in more detail in a few days. In the meantime, keep an eye on the moon in the evening skies. Today is the new moon, so in another day or two, you should see the beautiful sliver of the evening crescent moon start to appear low over the sunset. If you find it each evening for the next two weeks, you will see it grow gradually day by day as it creeps farther and farther away from the sunset in the sky. In two weeks, at the exact moment when the moon reaches the opposite side of the sky from the sun, we will see a dark shadow eclipse the moon.

AFT Update

I'm wrapping up the teaching of my college math course this week, but I've decided that I want to continue to focus on math for a while, and keep astronomy on the back burner. I've started tutoring math students online, and I want to do some research for some possible future workbooks or textbooks, or maybe a website, on various subjects in mathematics. (If you know any children, or adults, who would like a highly educated and competent math tutor, please let me know!)

I'm still deciding what to do with this newsletter. I enjoy writing it and I don't want to abandon it, but I don't want it to consume more than a small part of my effort. I plan to continue sending out issues, but on a sparser schedule, without my previous promise of at least one per month.

I hope you'll stick around for my (less frequent) updates on the interesting and beautiful goings-on in the sky! If you have any questions or suggestions, I enthusiastically welcome feedback.

The Dance in the Morning Sky

You may remember that most of the pantheon of visible planets was present in the evening skies last fall. Over the last few months, they have all migrated to the pre-dawn skies, and they currently provide a very nice lineup over the sunrise. This picture shows the view from mid-northern latitudes, about an hour before sunrise:

Facing East, About an Hour Before Sunrise

You can see the constellation of Cassiopeia in the upper left, and the joined constellations of Andromeda (the long, graceful arc) and Pegasus (the "baseball diamond") over the eastern horizon. Arrayed along the zodiac in a line tilted to the right, you can find four planets. Venus and Jupiter are the lowest, followed by Mars, and then Saturn.

I apologize for the late notice, but Jupiter and Venus, the two brightest of the visible planets, were extremely close together in the sky this morning, almost overlapping. This conjunction will continue tomorrow morning, but then the two planets will gradually drift apart, as Jupiter continues to rise higher over the sunrise, while Venus continues to sink lower into it.

As usual, whenever you see a lineup of planets like this, it gives you the opportunity to visualize the solar system around you: Use your imagination to picture the sun just below the horizon, and then imagine the line across the sky running through the sun and all of the planets. This line is the "ecliptic", and it represents the solar system, viewed by you from a point in space inside the plane of the solar system. (If you imagine a broad band across the sky instead of a fine line, you will be visualizing the zodiac, i.e. the celestial belt containing those special constellations that mark the "highway through the stars" or the "solar system in the sky".)

If you live near the equator or in the southern hemisphere, you can see the same lineup, but you will need to imagine rotating the celestial tapestry counterclockwise, making the solar system stand up roughly vertically (if you live near the equator) or tilt to the left into the northern sky (if you live deep in the southern hemisphere).

This spring has been quite cloudy here in Iowa, so I haven't yet enjoyed the morning planets myself. Here's hoping for clear skies where you live!

John Krieger