AboutSteven LJ Russo Expertise As a space science educator in a planetarium, my work centers around teaching people about the night sky and the solar system. I have a strong background in those areas, plus the history of NASA and spaceflight, and meteorology.
Experience Experience in the area. I have been an amateur astronomer for 47 years, and have been teachng space science in planetariums for 34 years. For 15 years I was a radio and television meteorologist, and for the past 20 years I have been a space science writer for two newspapers in New York State. I am a member of the Middle Atlantic Planetarium Society and the International Planetarium Society. I have had a number of articles published in several astronomy journals, including "The Constellation" and the "Planetarian". Education/Credentials. I hold a B. S. from Wagner College and an M. S. from State University of New York at Oswego. Awards and Honors. I have been awarded the "Fellows" award from the International Planetarium Society for more than 20 years of continuous service in the planetarium field.
Question How do we KNOW? We have the EM spectrum, we have telescopes, but I want to know exactly how to answer this question? Do we compare our star to others? Do we directly observe? Do we make educated guesses?
Thank you!
Answer Kim.
By using the spectral analysis of stars, we know, for example, how much Hydrogen and Helium is in a star. We also know from the "ratio" of H to He how long the star has been "burning" and at what temperature. So we put all that "data" together to get a very educated guess. When we say the sun is 4.5 billion years old, well, give or take a few hundred million years :)
