Musings from a Middle School Science Teacher
Teaching astronomy to 14 year olds can have its challenges, one of the biggest is keeping their interest. My astronomy unit was always taught in the spring and the students were beginning to lose their interest in anything academic. One of the the ways I would catch their interest was to ask them if they have ever thought of time traveling? Every time you look up into the night sky, you are time traveling and looking into the past.
When you step out at night and look at a star, ask yourself how far is that star from Earth? If that star is 10,000 light years away from our planet, that means the light from that star left it 10,000 years ago. What was happening on our planet 10,000 years ago? Each of the stars we look at in the night sky are different distances from our planet, which means the light left those stars at different times in our planet’s history.
The light you are seeing may have left that star when megafauna roamed the Earth’s surface, or when the first ships sails our seas.
Using telescopes, we can peer into the far reaches of the cosmos, and see light that left stars before our own Sun ignited and our solar system had even formed!
When we look up into the night sky, we tend to take the stars we see for granted. Each night their light shines down on us, every night we look up, they are there. We see the light that left that star, yet that star may no longer exist, it could have already used up its fuel and ended its existence long ago, but its light is still traveling through the galaxy until it reaches us.
The next time you look up at the night sky and see the stars that are so familiar to you, do a little time traveling and ask yourself when that light left its star, and what was our planet like at the time?
From the Editor:
The farthest individual star visible to the naked eye is often cited as V762 Cassiopeiae, located about 16,000 light-years away in the constellation Cassiopeia. However, the most distant object visible to the naked eye is the Andromeda Galaxy (M31) – 2.5 million light-years away. M31 appears as a fuzzy patch rather than individual stars, and requires very dark skies to see.
Top 10 Brightest Stars
| Rank | Star Name | Constellation | Distance (Light-Years) |
| 1 | Sirius (The Dog Star) | Canis Major | 8.6 |
| 2 | Canopus | Carina | 310 |
| 3 | Rigil Kentaurus (Alpha Centauri) | Centaurus | 4.4 |
| 4 | Arcturus | Boötes | 37 |
| 5 | Vega | Lyra | 25 |
| 6 | Capella | Auriga | 42 |
| 7 | Rigel | Orion | 860 |
| 8 | Procyon | Canis Minor | 11.4 |
| 9 | Achernar | Eridanus | 144 |
| 10 | Betelgeuse | Orion | 640 |
About the Author
Constance Martin-Trembley is a retired middle-school science teacher, and a volunteer NASA/JPL Solar System Ambassador.
She was a Girl Scout leader in the 1990’s where she had two troops ranging in numbers from 36-42 girls. She chose to teach the girls about science and focused on the badges that promoted those topics with the goal of proving to the girls that they were capable of accomplishing them..
She also taught her own children to look up at the night sky, which was easy to do as she has a husband who shares her passion.
