jump to navigation

Cassini’s Legacy September 11, 2017

Posted by aquillam in Astronomy, MichiganAstro, Science.
Tags: , , ,
add a comment

As the Cassini mission comes to an end, NASA and JPL ponder what its legacy will be.

When the mission started, I had just recently started working as the outreach coordinator for Michigan Astronomy, and the presentations I did about it were some of the first of my career here.

My how the time flies.


Venus and the Beehive August 30, 2017

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
Tags: , , ,
add a comment

If you happen to be up around 6 AM local time the next few mornings (August 31 – September 2, 2017) grab a pair of binoculars. Venus skims past one of my favorite open clusters in the pre-dawn hours.

Look east, between the Big Dipper and Orion, just below Gemini. You won’t be able to miss Venus. It’ll even shine through light cloud cover! If it’s clear, point your binoculars that way and you’ll see the Beehive cluster, so called because it sort of looks like a bee skep tipped on its side with the bees buzzing around it (a skep is the round, woven grass type of beehive.) It’s a fairly bright cluster, so even a small pair of binoculars will do. You probably won’t want to haul out the telescope for this because you need a 2º field of view, which most telescopes won’t do.

If you live in really dark skies, plop a camera down on a tripod and try taking a 1 – 2 second exposure. Longer will capture more stars, but overexpose Venus.

Here’s a chart looking east at 6 AM on August 31 from Ann Arbor:


Eclipse glasses are not the only safe way to view an eclipse August 18, 2017

Posted by aquillam in Astronomy, MichiganAstro.
Tags: ,
add a comment
So here it is, a couple days before the eclipse, and there are no eclipse glasses to be found anywhere. You tried calling the nearest observatory, but there’s no one there because they’ve all gone to the Path of Totality! What will you do?? How will you watch this once-in-a-lifetime event??
Calm down. It’s ok. Just go to your kitchen and grab a paper plate and a pen or pencil. No paper plates? That’s ok, any heavy paper will do. An index card, card stock (like that birthday card you haven’t recycled yet), the subscription cards that fall out of magazines, or anything that you can hold horizontally and it doesn’t droop too much. If you have an empty but unflattened box, that’s even better, but skip down a couple steps.
Once you have your piece of heavy paper and a pen or pencil, you’re ready to make a simple projector. Take the pen or pencil and poke it through the paper.
To use it, go outside, hold the paper horizontally and look at its shadow on the ground. In the middle of the shadow will be an image of the Sun! It’s a bit better if the ground is smooth, but during the eclipse it won’t really matter.
The cleaner and rounder the holes are, the better. If you have a little more time, you can make a big hole and tape a piece of foil over it, then poke holes in the foil. This makes it easy to try patterns, like these NASA folks
If you have an unflattened box and some time, grab that foil and make a cereal box viewer.
While you’re at it, try some experiments: (here’s the part that totally blew my mind back when I was an undergrad) the shape of the hole doesn’t matter that much. Make square, rectangular, triangular holes. Pull out those fancy scrapbooking paper punches. The image of a light source will always be the shape of the light source as long as the hole isn’t too big!
And that brings us back to the kitchen, because colanders are a whole lot of fun at eclipses!
With all of these “pinhole projectors” remember, they’re projectors: look at the image on the screen (or ground)!
Finally, keep some perspective. It’s not really a once-in-a-lifetime event, unless for some reason you are completely unable to travel. There are, on average, 2 solar eclipses per year, though only about half of them are total. Also, they have an annoying tendency to be visible only in really inconvenient places, like the middle of the ocean, or above  the arctic circle. It might not be easy, but it IS possible.

Summer solstice 2017 June 19, 2017

Posted by aquillam in Astronomy, MichiganAstro.
add a comment

The June Solstice occurs at 04:24 UT on June 21, 2017. That’s just after midnight EDT, so for most of the US the solstice falls on the 20th!

Here in Ann Arbor, the longest day of the year will actually be the 20th, despite the solstice falling on the 21st. That’s because we’re far west in the time zone, our clocks are ahead of the Sun. A bit farther east, say in New York, the 20th and 21st are basically equal in length. That’s more what you’d expect for a solstice close to midnight.

So enjoy the half second or so of extra darkness on the solstice.