Reflecting on the Transit of Venus

Transit of Venus broadcast live via NASA TV app, streamed wirelessly to my Apple TV from my iPad2.

As I was checking out my site’s stats this morning, I noticed that a few folks were coming to my site by searching for “transit of venus for kids”. I have kids, and I June 5th’s  dinner explaining the transit, streaming it live via NASA TV on our television, then (with my husband) taking my kids outside to see it for themselves. They seemed to understand what they were seeing and what I was explaining, so I thought that perhaps I’d tell you all what I told them.

A long time ago, scientists thought that everything we see up in the sky revolved around the Earth. The moon obviously did, so the thought process was that everything else must too.  This simplifies things a bit, because when I say scientists, I really mean those in western Europe. There were star gazers in other countries and other cultures who were very aware that the Earth was on a journey around the Sun and not the other way around.

But for my purposes, I wanted to set the stage that the great Galileo lived at a time where his discovery was against publicly accepted knowledge.

Let’s segue to Galileo.  He built a telescope because the technology of the time was insufficient to view the things in the sky he was hoping to investigate and use to verify his mathematical estimations. He was starting to believe that while the moon did revolve about the Earth, the Earth herself might revolve around something too.

Using his telescope, which wasn’t even as strong as a telescope you might have in your own home, Galileo gazed at Jupiter and found it also had moons! He only saw four of them, but that was enough to support his theory. The Earth has a Moon. Jupiter has moons. Maybe the other planets have moons, and maybe everything doesn’t orbit the Earth.

Next came Venus. Galileo was doing some calculations of where he expected to find Venus if it’s orbit was actually around the Sun and not the Earth. If it orbited the Sun, every once in  a while it should appear to the Earth that it would cross in front of the sun. In front of the sun!? If Venus marched in front of the sun from our point of view, then it has to be between the Earth and the Sun. And if it’s between the Earth and the Sun, it really should orbit around the Sun and not the Earth.

This wasn’t proven until folks like the Salford stargazer William Crabtree who in 1639 was the first to observe the Venus transit. You can read about him at:—video

The tracking of the transit of Venus was so important, that just like we send science spacecraft and set up telescopes to observe and discover new things about the universe around us, the great Captain Cook set sail to Tahiti where he successfully observed and took data on the transit of Venus.

NASA has a little writeup about Captain Cook’s Tahiti voyage here:

Technology developments like a special clock that worked on the unsteady voyage on the ocean for Captain Cook and crew, and better telescopes developed by Galileo, helped scientists discover and learn new things, or confirm things they’d been thinking were true. Just like then, NASA and other scientific agencies, academia and companies continue this wonderful tradition of technology development today.

So, I told my kids, at the end of this talk on the history of science and  Venus, that science is just as exciting now as it was when Galileo and Captain Cook were out discovering new things. We are using their same techniques to discover new planets around far away stars. If you have a thought or theory about how things work, even if that thought is different than other folks around you, don’t assume you are wrong. Investigate. Gather data. Observe. The universe is an amazing place and she is just waiting for us to learn.

In short, Science = Awesome. Then, Now and into the Future.

Or at least that’s what I think. 🙂