Eclipse-mania in Columbia, MO!

The university town of Columbia, Missouri is in the throes of total eclipse-mania this weekend, in preparation for Monday’s big event! CCSU astronomy professor Kristine Larsen and department alumna Jessica Johnson are among the thousands of eclipse enthusiasts who have descended upon Columbia in anticipation of the Great American Eclipse. The city has rolled out the red carpet in preparation of its day in the sun. While some businesses are advertising special eclipse viewing events, others are planning to be closed during the eclipse, in order to allow their employees to watch alongside all the out-of-town visitors.

Wherever you are planning to view the eclipse from, please be safe and have a great time!


Where to watch the Great American Eclipse online and in person


[Projection system for viewing the partial eclipse in Connecticut]

If you are planning on watching the [partial] Great American Eclipse from Connecticut and don’t want to watch it alone, here are some locations that are having live viewing parties. Please contact them directly about registration and other important information.

There are also websites and tv channels that will stream the total eclipse live.



More safety tips for the August 21 solar eclipse

There has been a lot of press lately about safely viewing the August 21 solar eclipse. The bottom line is that only the 2.5-ish minutes of totality are safe to observe with your unaided eyes (and the eclipse will NOT be total in Connecticut!). Those of us in the partial eclipse zone should NEVER look directly at the sun without proper eclipse glasses! If you want to be 100% safe, use a pinhole projection system, such as the box pictured above, or to watch it on television or on the internet.

If you want to use eclipse glasses, remember the bottom line is that the safe use of eclipse glasses is YOUR responsibility. The following are steps that I use in my own eclipse viewing:

  1. Make sure your eclipse glasses are obtained from a reputable source. Note that this is merely one step in the process and by itself cannot guarantee your eye safety! The glasses must have labeling that says “safe for direct solar viewing” or “safe for direct viewing of the sun.” Glasses need to meet the ISO 12312-2 standard adopted in 2015 (these glasses block UV and IR as well as visible light). The AAS ( has a list of some reputable sources (be sure to read their various notes and disclaimers). Updated: There are apparently bootleg glasses on the market that claim to meet these standards (and their websites make false claims). Make sure you only buy eclipse glasses from reputable sources (such as a museum or science center). There are many libraries and amateur astronomy groups that are handing out free glasses as well.
  2. Inspect the eclipse glasses for any defects or damage both when you initially receive them and, most importantly, RIGHT BEFORE you use them. Make sure that the filter material is not loose or compromised in any way. Inspect the filter material for cracks, creases, holes, tears, gaps, or other problems. Hold the glasses up to a light (NOT THE SUN) and look for any pinpricks or other defects that let light through. If you see any of these defects, immediately destroy the glasses and throw them away.
  3. Do not use the eclipse glasses with any optical aid except your contact lenses or eye glasses. The eclipse glasses are shaped that way because they are only meant to be used with your eyes. Do not use them with cameras, binoculars or any other optical aid. Wear them over your regular eyeglasses.
  4. Put your eclipse glasses on BEFORE you look up at the sun. Place your eclipse glasses on, fully covering your eyes, before you look up at the sky. At this point you should not be able to see anything through the eclipse glasses – everything should look black. Once you have them firmly in place, look up in the direction of the sun. Do not remove your eclipse glasses until you are looking down toward the ground again. Do not look at the partial phase with just your eyes, or through clouds. This applies whether the eclipse is 10% partial or 99% partial! Always supervise children’s use of eclipse glasses at all times. Very young children should probably not use eclipse glasses because of the risk of them taking them off and trying to look directly at the sun. If you have any doubts about their ability to safely use eclipse glasses, switch to pinhole projection immediately.
  5. Make sure the sun looks sharp and relatively dim when seen through the glasses. The sun should look comfortably dim when seen through the glasses. The image should also be crisp, clear and not have a halo or any other strange effects. If the image looks fuzzy, or you feel it is too bright, look away from the sun immediately, remove the glasses, destroy and discard them. This image shows you how the sun’s image should appear in proper eclipse glasses.

Note that these are merely some steps that I personally take; for more information, see the AAS eclipse website. A detailed report on eclipse safety can be found here. Again, the ultimate responsibility for safe eclipse viewing is yours! If you feel uncomfortable in any way with your eclipse glasses, please err on the side of caution and switch to pinhole projection.

Note: This document does not constitute medical advice. Readers with medical questions should contact a qualified eye-care professional.

Upcoming Free Eclipse Talks


[Partial phase of a solar eclipse viewed in Egypt in 2006]

If you haven’t attended one of Dr. Larsen’s free public lectures on the upcoming solar eclipse you still have several chances! Please contact the host institutions directly to reserve your spots:

Wallingford Public Library: August 9, 7 PM

Bristol Public Library: August 14, 6:30 PM

CT Audubon Society (Glastonbury): August 15, 6:30 PM


Preparing Pinhole Projectors for the Partial Solar Eclipse

[Three homemade pinhole projection systems for the August 21 solar eclipse]

If you plan on watching the August 21 solar eclipse (and why wouldn’t you?) now is the time to plan on viewing it SAFELY! The sun will be about 2/3 eclipsed as seen from here in Connecticut at its greatest extent, which means it will NOT be safe to look at with an unaided eye. If you have purchased solar eclipse glasses, that’s great. If not, you can still safely view the eclipse using a pinhole projection system, like the ones shown above.

[How to align a projection system and a typical project image]

In each case, you need to make a literal pinhole in one end (poking one into aluminum foil is more reliable than cardboard, as shown) and a white screen on which to catch the image. You point the pinhole end at the sun, and minimize the shadow to align the tube or box (as shown above). Your image will be relatively small and depends on the length of the tube or box. The roughly 1 meter long systems shown above give a projected image that is about 1 cm in diameter.

For more information on how to make your own projection systems, see the following websites:



Astronomy Goes Old School – REALLY Old School

[Left: Medieval scholars learn how to use a cardboard astrolabe at the 2017 International Congress on Medieval Studies in Kalamazoo, MI; Right: CCSU Students in a Cultural Astronomy class learn how to use astrolabes]

Astronomy has rightly been called the oldest science. From using the phases of the moon to record the passage of time and make calendars to monitoring the position of the sun at sunrise to determine the summer solstice, humans have been studying the heavens throughout recorded history. Technology such as the telescope and sensitive cameras (not to mention space probes!) has greatly enhanced our ability to understand the universe around us. But one particular type of astronomical technology is decidedly old school – really old school! The origins of the astrolabe are lost to history, but probably date back to around the 6th century CE. Part calculator, part star map, part surveying and navigational tool, and part work of art, the astrolabe has been used for centuries to calculate the time from the position of the sun or stars, estimate one’s latitude, and measure the heights of buildings and trees, among other uses. Although they were largely replaced by more “modern” technologies by the 18th century, they are still an excellent tool that can be used to teach basic astronomical concepts, as well as demonstrate the close connections between astronomy, history, art, and religion (as they were used to calculate prayer times by both Christians and Muslims in medieval times).


[So-called Chaucer Astrolabe in the British Museum]

I have greatly enjoyed teaching students how to use simple cardboard astrolabes, both in a Cultural Astronomy course as well as as a guest lecturer in a Medieval History class, as well as giving lectures and workshops at other universities and numerous conferences. If you ever get the chance, peruse the astrolabe collections at the Adler Planetarium in Chicago and the Oxford University Museum of the History of Science. I have been fortunate to have seen both these collections in person and they are quite simply out of this world!

— Kris Larsen

Kudos to Kepler for a Job Well Done!


[The Kepler Space Telescope Main Mission’s 4000+ exoplanet haul!]

NASA recently announced the final planet-finding tally for the main mission of the Kepler Space Telescope: a whopping 2335 verified planets outside our solar system and another 1699 candidate planets yet to be verified. Among these 4000+ potential planets are 49 potentially habitable bodies – rocky planets about the size of earth that inhabit the so-called Goldilocks Zone of their star (you know, not too hot, not too cold, just right!)


[Exoplanet discoveries by year (does not include recent Kepler announcement)]

Take a minute and consider what this means. When I started teaching at CCSU back in 1989 there were NO planets known orbiting sun-like stars outside our solar system. None. Nada. Zippo. By the time I became tenured we finally knew of a single planet around a sun-like star. By the time I became a full professor we had discovered a handful. In fact, until Kepler started staring at over 100,000 stars in one area of the sky (near Cygnus) in 2010 the number of known planets outside of our solar system was only a few 100.

And then everything changed. Not only did we discover that planets were relatively common, but that there are more types of planets than astronomers ever imagined! Superearths, mini Neptunes, hot Jupiters, lava planets…. Suddenly our original sample size of 1 known solar system wasn’t so representative of the universe as a whole.

While the main Kepler mission has ended (thanks to failing systems that point the telescope), the extended K2 mission is still making discoveries, including new exoplanets. The TESS satellite will likely reveal another slew of exoplanets after its launch next March. But Kepler will always have a place in my heart as the telescope that COULD and DID change the way we think about the universe and our own pale blue dot of a world.

— Kris Larsen