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Wednesday, April 3rd 

Madelyn Helling Library

Community Room

7:00 pm


This month's talk: North Pole, South Pole

Kurt Simon

You might expect the rocky inner planets (Mercury, Venus, Earth and Mars) to have similar magnetic fields since they formed in much the same way.  They do not. Earth has a far larger field than any other rocky planet; in fact, no magnetic field at all has been detected on Venus and the other rocky planets have only tiny magnetic fields. Not only is Earth’s field far larger, for many years the wandering of the poles was considered one of the great unsolved problems in science. Today, the study of our home planet has unraveled much of the mystery of the wandering pole and the elusive “pole flips” whereby the north and south poles reversed position. Kurt will describe the development of our understanding of the interior workings of Earth and the fascinating science that has led to where we are today. 

The images below are from NASA and show the "normal" field on the left; and what might happen during a field reversal on the right. And you thought of the Earth's field as a simple bar magnet! Kurt will straighten out your thinking! (I couldn't resist). Come and learn from our local expert!


All are welcome! Bring a friend!


President’s Rant

Happy April my friends,

2019 is one fourth completed, and I can almost write the year correctly the first time without thinking. Mostly.

I read as much as my retirement schedule will allow. When the old guys told me that they had less free time after they retired than they did when they were still working, I didn’t believe them. After all, how could you be busier when you don’t have a job? It’s a fact, though!

One thing that I have been reading and hearing about is that this year is the 50th anniversary of the first Moon landing. Apollo 9 launched on March 3rd, 1969, orbited the Earth for 10 days and came home. Apollo 10 launched on May 18th, 1969, orbited the Moon 31 times, and came home 8 days later. Then, on July 16th, 1969 Apollo 11 launched for the first manned Moon landing. The lunar module landed on the Moon on July 20th and lifted off to rendezvous with the command module on July 21st. The command module splashed down in the North Pacific on July 24th. Three manned launches and recoveries in five months all due to a boggling amount of blood, toil, tears and sweat.

I remember where I was on July 24th, 1969. I was waiting to be discharged from a hospital after I had an industrial accident. The nurse came into my room and asked me “Don’t you want to watch the astronauts come back from the Moon?” and turned on the TV for me. I don’t believe that I even knew that they had gone. I wasn’t paying too much attention in those days. Some of us take longer to get going than others.

Perhaps the rain will give us a short break this month so we can do a little star gazing. I may need to be re-trained if I don’t get some eyepiece time soon. I’m not complaining though, the precipitation has been welcome this winter/spring. I just want a little dry break around third quarter and new Moon. That’s not asking too much, is it?

See you at the meeting on April 3rd.



Outreach - David Buchla

We had some great volunteers and a nice crowd at Scotten School Science Night on March 14. We were able to help kids construct star wheels and we had several scopes outside (in front this year) with a line of enthusiastic kids and parents to see the view of the moon. Even though the evening was early, we were able to catch good views. Thanks to our all of our volunteers; you may have sparked a few new scientists!

Speaking of the moon, John and I will be setting up a display on four famous people that had "Moon Dreams" in the library's display at the entrance. It will be up for the month of April, so check it out.

Last month I mentioned we would be doing outreach for children this summer at several branches of the Nevada Co. library. We have dates now and I will get them on our member's calendar soon. The first outreach is at 1 pm at Madelyn Helling library on July 18th. The second one is at the Bear River branch at 10 am on July 20th. The last one is at 1 pm at the Grass Valley library. We plan to do star wheels at each event, and, assuming clear skies, will look through my H-alpha solar scope; an alternate activity is to do a solar system model for the inner planets at 1,000,000 miles to the foot. This one requires a lot of space, so we may only get to Earth on our voyage. As always, volunteers are welcome if you can help.

Astronomy on Tap

NC Astronomer members continue to enjoy the beer  and 'blather' at the Ol' Republic Brewery. The beer selection at the Brewery is quite comprehensive, they seem to enjoy naming beers after astronomical topics and the environment is designed for in depth conversations on deeply philisophical questions. 

Image result for astronomy on tap

Each month we choose several current topics in Astronomy and share our ignorance.

 Astronomy on Tap will meet on

The third Monday of the month at 5pm

For April 2019 we will meet on tax day, so we can jointly cry in our beer! 🤥

Come and join the conversation at

Ol' Republic Brewery below SPD in Nevada City!


Secretary/Treasurer - Paul Bacon


Our Mission is:

'Bringing' Astronomy to the Public'

a BIG Thank You

to all our members who join and make our programs possible!

I will be collecting membership contributions

($20/year for member or family)

at our Monthly Meetings,

If you can't make the meeting, send your check to:

          NC Astronomers, %Paul Bacon,                    
10572 Oak St., Grass Valley, CA 95945


This article is distributed by NASA Night Sky Network

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit to find local clubs, events, and more!

Mars the Wanderer

By David Prosper

April’s skies find Mars traveling between star clusters after sunset, and a great gathering of planets just before sunrise.

Mars shows stargazers exactly what the term “planet” originally meant with its rapid movement across the evening sky this month. The ancient Greeks used the term planete, meaning wanderer, to label the bright star-like objects that travelled between the constellations of the zodiac year after year. You can watch Mars as it wanders through the sky throughout April, visible in the west for several hours after sunset. Mars travels past two of the most famous star clusters in our night sky: the Pleiades and Hyades. Look for the red planet next to the tiny but bright Pleiades on April 1st. By the second week in April, it has moved eastward in Taurus towards the larger V-shaped Hyades. Red Mars appears to the right of the slightly brighter red-orange star Aldebaran on April 11th. We see only the brightest stars in these clusters with our unaided eyes; how many additional stars can you observe through binoculars?

Open clusters are made up of young stars born from the same “star nursery” of gas and dust. These two open clusters are roughly similar in size. The Pleiades appears much smaller as they are 444 light years away, roughly 3 times the distance of the Hyades, at 151 light years distant. Aldebaran is in the same line of sight as the Hyades, but is actually not a member of the cluster; it actually shines just 65 light years away! By comparison, Mars is practically next door to us, this month just a mere 18 light minutes from Earth - that’s about almost 200 million miles. Think of the difference between how long it takes the light to travel from these bodies: 18 minutes vs. 65 years!

The rest of the bright planets rise before dawn, in a loose lineup starting from just above the eastern horizon to high above the south: Mercury, Venus, Saturn, and Jupiter. Watch this month as the apparent gap widens considerably between the gas giants and terrestrial planets. Mercury hugs the horizon all month, with Venus racing down morning after morning to join its dimmer inner solar system companion right before sunrise. In contrast, the giants Jupiter and Saturn move away from the horizon and rise earlier all month long, with Jupiter rising before midnight by the end of April.

The Lyrids meteor shower peaks on April 22nd, but sadly all but the brightest meteors will be washed out by the light of a bright gibbous Moon.

You can catch up on all of NASA’s current and future missions at

Click to Contact
President John Griffin
Vice President Rick Bernard
Secretary/Treasurer Paul Bacon
Outreach Coordinator David Buchla
At Large Greg Ouligian
At Large Dan St. John

NC Astronomers
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First Wednesday Of The Month
Madelyn Helling Library
Community Room
980 Helling Way
Nevada City 95959

10572 Oak St.
Grass Valley, CA 95945

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