Eeek! I am excited about this activity I dreamed up for astronomy club! We are discovering the Sun by looking at its solar spectrum. We will make handheld spectroscopes and check out electrocuted gas to find out the solar composition. This is fun for kids because spectroscopes make lots of rainbows, and electrocuted gasses are just cool.
What do electrified gasses have to do with our sun? To answer this, we have to think about another question. How do we know what the sun is made of? Even now we can’t journey to the Sun to take a sample, and at one point we couldn’t look up this information in a book. How do we know what elements are in the sun? We look at it. Not with our eyes of course! We look at the light from the Sun and split it into all of its colors using a device called a spectrometer. This gives us a rainbow looking image that we call a solar spectrum. These colors are from all of the gasses in our Sun.
Each gas has it’s own spectrum unique to it – much like a fingerprint. The state of electrons buzzing around an element determine what colors a gas will glow. Hydrogen, with just one proton, neutron, and electron, is the simplest spectra, while heavier elements make up their own rainbows. If we look at the solar spectrum and then look at the spectra of gasses we can determine the solar composition.
I ran this program with all of our island 5th graders and had a ball, but there was one thing missing – really discovering the Sun’s composition through spectra. Looking at the gasses through spectral tubes kids saw the pretty lines but weren’t able to make the connection about which gasses are in the Sun based on spectra.
Overhead transparencies to save the day! I printed a ton of different elemental spectra on transparency sheets, making see-through cards. Families will put them on top of sample solar spectra (I made easy, medium and hard) and discover the most common elements in the sun the same way NASA scientists have done!!