251E-263-Catching Shadows

Students and teachers are doing real science by measuring the shadows cast by distant objects in our solar system.
For years humans knew Pluto, the first Trans-Neptunian object to be discovered, only as a moving point of light in the night sky. It wasn't until 58 years after it's discovery that astronomers were able to observe a star as Pluto passed in front of it. These data gave an accurate diameter and also proved that Pluto has an atmosphere. There are estimated to be 100,000 Trans-Neptunian bodies larger than 60 miles or so in diameter. They have stories to tell about the beginning of the solar system. Additionally, sometimes, a passing star changes one of their orbits sending it into the inner solar system and perhaps near to us.