FirstLight Astronomy Club

33°29.6'N / 117°06.8'W / 1190 ft.


When massive traumatic planetary events occur on Earth, specifically those which strike down thousands if not hundreds of thousands of humans in a fell swoop, people like myself feel compelled to defend the planet.

It's not any attempt to minimize the suffering and death that occur in places like Haiti or Indonesia; I would never do that. What happened in Haiti a couple weeks ago is a genuinely tragic historical phenomenon.

But the "culprit," namely planet earth, is designed in such a way that events like Haiti's earthquake have happened countless times before, they will happen again this year, and they will happen plenty more in our future. There is no surprise there.

I would argue, though, that the process which shakes our surface is the same process that makes this such a beautiful place to live.

You will recall that out planet has a thin, thin layer of solid rock - just miles thick - on top of gooey innards. This thin layer, our crust, is broken into a couple dozen plates which float about very slowly across the top of the planet.

As the plates slide into and by and away from each other, there is, of course, a whole lot of shaking going on. We in Southern California know well and first-hand what can happen when two tectonic plates scrape by each other.

The same thing happens when plates crash together head-on, or split apart. You may remember that although it was massive wave that killed all those people in the Indian Ocean tsunami in 2004, it started from a slipping of two plates.

But the movement of the plates is absolutely necessary.

The movement provides us with separated continents and high mountains and islands and oceans. With no uplifting forces our planet would have eroded down to a smooth sphere long ago and we would be completely covered in water. Plate tectonics have also been involved in the steady removal of carbon dioxide from the atmosphere over the eons, helping to insure we would not end up like our hellishly hot, carbon dioxide laden sister, Venus.

Earthquakes should not take us by surprise. In fact, if I may be so bold, I feel confident in predicting there will be massive earthquakes in the near future in places like Persia, Turkey, Indonesia, Oregon/Washington, and of course, our own Southern California. When? I have no idea; but they will occur.

Earthquakes, volcanoes, hurricanes, and floods are all by-products of the design of this awe-inspiring planet and we can live through them all if we are prepared. Tragically, our neighbors in Haiti were not. Will we be ready ourselves when it is our turn?

Galileo, Jupiter, and 1610

Now that 2009 is behind us, the official "Year of Astronomy" is over. But is that going to stop us here? Of course not. In fact, let's pick up where the Year of Astronomy started it all, with Galileo.

It was in 1609 that Galileo revolutionized astronomy with his upgraded, improved version of a recently created tool called the telescope. It was department store quality by today's standards, but it opened up a whole new realm for those of us who are fascinated by the skies. Now we could see deeper into the heavens and resolve objects we didn't even know existed. Subsequent discoveries helped change the worldview of the western world forever.

One of his discoveries took place 400 years ago this week, and featured an object in the sky you can see this evening for yourself. On 7 January 1610, he fixed his tiny telescope on Jupiter and around it found "three fixed stars, totally invisible by their smallness."

That was an important discovery in itself, but what made this historic was the observations he made over the following week when, quite to his surprise, those tiny "stars" - and another newly discovered one - had moved! (His drawings are shown here.)

It appeared that these tiny "stars" were really going around Jupiter, as if they might be tiny jovian moons. You have to understand the paradigm at the time which dictated that such a thing just could not happen. The cosmic philosophy then was based on Aristotle's teachings that everything in the universe went around the Earth.

So for someone to boldly announce that there were tiny objects orbiting something other than the Earth was novel, and somewhat dangerous, to say the least. It brought to the forefront the question that if little moons could orbit a bigger object, why couldn't the earth orbit the sun?

But this wasn't the end of Galileo's battering of the aristotelian wall. He also found "imperfections" on the Moon - mountains and "seas" - which flew against the established view that all heavenly objects were unblemished. He also observed spots on the sun, further evidence of imperfections.

Later in 1610, and very importantly, he observed that the set of phases that Venus went through - similar to the phases of the Moon - could only be explained if Venus went around the sun, and not around us.

The year 1610 was a big year in astronomy, a great big year. This week alone, 400 years ago, was a monumental week. You can relive it yourself by going out in the next day or two and scoping out Jupiter setting in the southwest after sunset. See if you can pick out the Galilean satellites yourself. Studying more deeply this art of astronomy may ultimately change your worldview, as well.
Temecula Valley High School / Temecula, CA · Some images © Gemini Observatory/AURA Contact Me