Astronomers study planets, stars, galaxies, and other celestial bodies. What is an example of a astronomers? Galileo Galilei is an example of an early observational astronomer who used a telescope and recorded his findings. Tools that modern observational astronomers use to study space include radio waves, cameras, infrared technologies, ultravioletRead More →
Q: Why is a parsec 3.26 light-years and not some other number? A: A parsec, or “parallax second,” is defined as 3.26 light-years because of how it is measured. Earth circles the Sun, making one complete orbit per year. What measurement do astronomers use? To measure the distance of aRead More →
There are only a few thousand professional astronomers in the U.S. Many are professors at colleges and universities. They teach astronomy courses and usually do research. Others work at NASA or, like me, with companies that work with NASA, or at the National Observatories. Nearly all professional astronomers have aRead More →
The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy. … Every element — and combination of elements — has a unique fingerprint that astronomers can look for in the spectrum of a given object. Which one of the following can astronomersRead More →