Section updated: Mar. 24th, 2026.
You may have heard of π Day – March 14th (as in 3/14 as the first 3 digits of the mathematical constant of π). That day is also Albert Einstein’s birthday, the day that Steven Hawking died, and the anniversary of Uranus’s discovery, too. Well, I came across a Reddit discussion about an idea of days for the other mathematical constants. A day to represent the imaginary number was proposed by Putty Putman on his webpage ( https://www.puttyputman.com/post/imaginary-number-day ). His argument is based on the complex number plane, in that i is one basic unit up on the vertical imaginary axis and also represents 1/4th of the unit circle there. So, he calculated the day that is 1/4th of the year, or 365/4 ≈ 91. The 91st day of the year is April 1st, which is so appropriate! So, I’m following his lead on this and mark the day to be declared so, too. What could one do on such a day? Well, people could dress up in fantasy inspired clothing or be like the mathematician Leonhard Euler (though I’m not certain how to wrap that hat-cloth of his!) or play complex games or eat imaginary food! Others could offer up even better ideas. Would it be silly? Of course it is! And why not have such a day? It would give mathematicians chances to have fun with it and provide them a “teaching moment opportunity” to talk to others about this difficult to ponder concept for most folks, and yet show how we actually use it, such as the discovery of anti-matter. Have you ever had a PET scan done? That is an example of medicine capturing and imaging anti-matter positrons that are emitted out of your body!
NASA intends to launch Artemis II, early in April. Once launched, during their first day up, the crew will test the Orion spacecraft Integrity with rendezvous and docking tests like those of the Gemini missions, before making the 4 day trip out to the Moon. They’ll arrive near the Moon’s 3rd quarter phase. They’ll whip past the Moon and become world record holders as for having traveled the furthest away anyone has ever gone from humanity. Then by its gravity, they will fall back into a “free return trajectory”, pass the Moon again and return to Earth for landing. All the while, they’ll run biology tests on themselves and run tests on the spacecraft.
NASA engineers have fixed the fuel leak, the cooling helium flow, replaced the expiring batteries and even got a wiring problem found and fixed. As of this writing, the astronauts are in their quarantine and the launch looks good for the scheduled Wednesday, April 1st date with an 80% chance for launching by the weather. Their 2 hour launch window starts at 6:24 pm and lasts until 8:24 pm.
We wish the crew of the Integrity
a wondrous voyage,
a most successful mission
and a safe return home!
The transition to summer night skies will become more apparent on the 3rd as it won’t really get dark until 8:30 pm. We’ll start with M45 the Pleiades open cluster. Nearby it will be seen the pale aqua planet Uranus. Its spin axis is obliquely tilted over by 98° from the ecliptic plane. Because angular momentum is conserved, its axis always points out in the same direction in space. But now in its 84 year orbit, the planet has traveled around the Sun so that its north pole is oriented back at the Sun and us as well. So, when we observe it, we’ll look right at its north pole.
We’ll also see Orion’s Great Nebula and check in with “Cluster 37”. In Gemini, we’ll see Castor (a triple binary star system) and Pollux (the closest red giant star to us), the planetary "Eskimo Nebula" (NGC 2392), the distant "intergalactic wandering" globular cluster (NGC 2419). The open cluster of M35 will be with the twins and the planet Jupiter with its 4 moons appearing near its sides will be there.
In Cancer the crab we’ll find M44 Praesepe (aka the Beehive) and the King Cobra clusters, the "UFO Galaxy" (NGC 2683),
We’ll look at the complex Xmas Tree OC & Cone Nebula (NGC 2264), the open cluster NGC 2244 seen through the Rosette Nebula, the Butterfly Cluster (M93), the Tau Canis Major Cluster (NGC 2362), the syzygy of the 2 open clusters in NGC 2451, and one of the best open clusters in the sky: NGC 2477, the triple dividing open cluster M48, Messier's Lost Cluster (M47), Caroline's Cluster (NGC 2360). There will be a much to see on this night!
The transition to summer night skies will become more apparent on the 21st as it won’t really get dark until 8:30 pm. We’ll start with M45 the Pleiades open cluster. Nearby it will be seen the pale aqua planet Uranus. Its spin axis is obliquely tilted over by 98° from the ecliptic plane. Because angular momentum is conserved, its axis always points out in the same direction in space. But now in its 84 year orbit, the planet has traveled around the Sun so that its north pole is oriented back at the Sun and us as well. So, when we observe it, we’ll look right at its north pole.
We’ll also see Orion’s Great Nebula and check in with “Cluster 37”. In Gemini, we’ll see Castor (a triple binary star system) and Pollux (the closest red giant star to us), the planetary "Eskimo Nebula" (NGC 2392), the distant "intergalactic wandering" globular cluster (NGC 2419). The open cluster of M35 will be with the twins and the planet Jupiter with its 4 moons appearing near its sides will be there.
In Cancer the crab we’ll find M44 Praesepe (aka the Beehive) and the King Cobra clusters, the "UFO Galaxy" (NGC 2683),
We’ll look at the complex Xmas Tree OC & Cone Nebula (NGC 2264), the open cluster NGC 2244 seen through the Rosette Nebula, the Butterfly Cluster (M93), the Tau Canis Major Cluster (NGC 2362), the syzygy of the 2 open clusters in NGC 2451, and one of the best open clusters in the sky: NGC 2477, the triple dividing open cluster M48, Messier's Lost Cluster (M47), Caroline's Cluster (NGC 2360). There will be a much to see this night!
When the day to celebrate the most amazing astronomical body comes around this year, I would ask people to make some effort to help improve our home planet Earth, even if it is just a simple thing. For example, if you go out on a daily walk for your personal exercise, then observe your surroundings, their natural beauty, the plants and animals around you. Make a mental note of things like recycling or garbage cans and where they are located. Then when you go out again, take with you some of those simple shopping bags that many stores give out and fill them up with recyclables or trash that you find on your walk and deposit them in the appropriate cans. Cities or towns do not offer “official jobs” to keep our environments clean. It’s really up to all of us to remove rubbish on the ground and their potential to become mosquito breeding sites. If many people do this, then much can be easily achieved. Doing this adds a few more steps to your walk; while making it a habit keeps your community clean and may encourage others to participate, too. Plastic objects are so much easier to capture and dispose of when they are large and singular. When they break down into millions of microplastic, or billions of nanoplastic particles, then they become a vastly bigger problem that spreads out to infect our waterways, our oceans, the animal life out there and ultimately, us.
If you choose to participate in “Earth Hour”, I ask that instead of just temporarily turning off some exterior lights for only an hour, that you use the hour to replace the lighting fixture to one of which all of its light is emitted downwards to the ground where it’s more needed and NOT wastefully upwards or outwards. Doing so stops it from spreading unwantedly into neighbors’ windows, into your surrounding natural area (which harms plants and animals that evolved to utilize the nighttime darkness), and into your nighttime skies, so that you and others can see more of the wonders of the night, not just for that one hour, but for many years to come!
And with darker nights means that you’ll be able to see more wonders, like the Lyrid Meteor Shower that will peak that same night. The shower will seem to radiate from a location about 8° to the west of the star Vega, but its meteors will be seen across the whole sky. So, you will want a clear view of the sky, without any lights to see its quickly moving particles from the debris trail of comet Thatcher. Its zero-hour rate (ZHR) is 18 meteors that move 49 km/sec (~30 miles per second) across the sky!
