Planetarium Newsletter - August 2017

Cosmic Curiosities

“Never have I beheld any spectacle which…so forcibly taught the lesson of humility to man as a total eclipse of the Sun.”
~ James Fennimore Cooper, 19th century American writer

Last Thoughts before the Big American Eclipse

Many moons ago, when I started working in the Planetarium world as a college sophomore, my astronomy professor showed me a video from the February 26, 1979 total solar eclipse in Canada. Wow! It was fascinating to watch this homemade movie of their adventure north to Brandon, Manitoba. Weather conditions were very cold but clear. The eclipse footage was spectacular and intriguing, but what I most remember was the noise.

It wasn’t the Sun and Moon making any sound -- it was the people. These 30 eclipse chasers were cheering and shrieking sounds of utter joy and amazement. They were moonstruck, literally, by its dark umbra shadow. As their transfixed eyes gazed upward, they shouted all about totality’s strange beauty -- the bizarre glow of the Sun’s corona that surrounds a black moon, the extraordinary deep blue colors that grow darker as they near the Sun, and the few stars and planets that shine in the darkened sky.

A cosmic seed was definitely planted after viewing that. I wanted to experience this eclipse euphoria myself. Total solar eclipses occur every 18 months on average so it should be no problem, right? I soon learned the Moon’s shadow only reaches a tiny part of the Earth, and our planet’s surface is 70% water. This means totality is rare. And you most likely will have to travel a long distance to see one. I was young with little money. My eclipse craving dimmed.

Then, in 1991, the Moon’s shadow would sweep over Hawaii and Baja California. This seemed like the perfect opportunity to satisfy my sky curiosity. I felt the urge; I wanted to go, but my pocketbook was crying no. I passed. I should have gone, especially after hearing the eclipse stories from friends and colleagues who made the journey. Though I missed the big event, they revived my eclipse dream and made it stronger.

The next opportunity was February 26, 1998 in Aruba, a small island in the South Caribbean Sea. I had a few more coins in the bank and was fortunate to afford the long trip south. (Escaping a cold Minnesota winter cemented the decision.) I joined a museum group from St. Paul and was able to help them out with my 10-inch telescope.

My first experience with totality went beyond anything I could imagine. We had a weather scare with some light rain, but it soon passed. Then totality struck. I finally knew what everyone was carrying on about. All the delight and dread people shared about past eclipse experiences now made sense. Yes, it was just a little black hole in the sky that lasted three and a half minutes, but it was so much more than that. The tiny eclipse kernel I carried with me from watching that video long ago blossomed that glorious day. The view from my telescope mesmerized me. That wondrous sight — the Sun’s red prominences, the white wispy corona — is firmly etched in my memory. Since then, I have been very lucky to observe three more total solar eclipses. They took me to the Greece, Zambia, and Italy. All were amazing and beautiful.

People often say it’s hard to put into words all that happens during a total solar eclipse. It’s true. These words are my meager attempt to convey why someone should venture into the path of totality on the 21st of August. I hope you can.


Alien Pulsar?

It was 50 years ago, in the middle of the American versus Soviet Union moon-race, when a bizarre radio signal from deep space had scientists stumped. It started on August 6, 1967 when Jocelyn Bell, a graduate student in astrophysics, detected a bizarre signal using a radio telescope array she helped build. The rapid pulsing radio “light” could not be identified. It was “beating” fast, one pulse every 1.3 seconds.

Explanations poured in. One idea speculated the radio detections were from an alien civilization. Bell recalls their thinking, “We did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission.” Not able to resist, the discovery team nicknamed the signal LGM-1, for "little green men."

Soon, more of these radio pulses were being detected. In about six months, astronomers had it figured out. The rapid radio signals were pulsars, very dense remnants from once massive stars. A pulsar is a type of neutron star, which was first theorized in 1934. They result from a cataclysmic supernova explosion. By the end of 1968, a total of 21 pulsars were known, including the famous pulsar in the Crab Nebula.

The pulsar discovery in 1967 started as a strange mystery, but it can still generate debates about how humans would respond to confirmed evidence of extra-terrestrial contact. How should we reply? Should we reply at all? Will there be an international discussion? Who speaks for planet Earth?


Water Moon?

Is there water on the Moon? Yes!

While a watery Moon has been known for awhile, a new study from scientists at Brown University, which recently appeared in the Journal of Nature Geoscience, reveals water in ancient volcanic deposits. The magma that created these deposits came from far below the lunar surface, making scientists wonder where the water came from in the first place. Could it come from icy comets early in the Moon’s formation?

A swarm of comets known as the Oort Cloud exist way beyond the orbit of Pluto. They can be jostled by a nearby gravitational tug, causing them to fall toward the inner Solar System where they might impact the Earth or Moon. Although the origin of the water remains a mystery, this new discovery will warrant further exploration of our nearest space neighbor.

If we decide to go back to the Moon — to start a research station or even live there — the availability of water will be of crucial concern. It is very heavy and expensive to transport. If you ever carried a 5 gallon container of water around, you get the idea quickly.

Back in 2009, NASA's Moon Mineralogy Mapper, an instrument on the Indian Space Research Organization's Chandrayaan-1 mission, took a very colorful image of the Moon. The image shows the lunar surface reflecting near-infrared radiation from the Sun. At higher latitudes, there is an abundance of blue colors signaling water.

Sky Sights


Jupiter is slipping away in the west, but you can still spot the largest planet shortly after sunset. After the Moon eclipses the Sun on August 21, look for it to slide by Jupiter on the evenings of August 24-25. The bright star Spica still shines nearby but will be harder to spot.



Saturn is not very high in the south after sunset, but easily visible. Only a few bright stars — Vega and Arcturus – will outshine the ring world. Look for the Moon to pass by early in the month.



Venus is brilliant in the morning sky. Just before the big eclipse on August 18-19, watch the Moon glow near the hottest planet. Orion the hunter can be seen to the south of this bright duo. If you’re really dedicated, you might see the brightest star, Sirius, extremely low in the night sky.



Mars  and Mercury are too close to the Sun to be seen this month, except during the total solar eclipse on August 21.

Star Map

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