Week of February 28, 2021

Twinkle, Twinkle


Stars twinkle when viewed from Earth, but not when viewed from space. The twinkle is caused by our atmosphere’s effects on starlight, which comes from very far away. Planets, viewed from earth, don’t twinkle, because they are much, much closer. For this reason, closer stars twinkle a little less.


“Shooting stars” or “falling stars” are not stars at all, but meteors and meteorites which burn bright as they enter the earth’s atmosphere and experience friction with the air. These typically consist of mostly space rock and dust, and meteorites make it to the surface while meteors burn up entirely in the atmosphere.


Our sun is big, bright, and warm in the summer sky, but is still about 93 million miles away. This means that even at the mind-boggling speed of light, if takes sunlight 8 minutes and 20 seconds to reach Earth.


What’s the closest star to Earth? The sun, or course, but the next is Proxima Centauri, which is really a three-star system. Even so, “close” is relative. Voyager I, already traveling at a brain-bending 38,000 mph, would take over 73,000 years to get there.


Stars are popular. They appear on the flags of 59 different countries, featuring stars with anywhere from 4 points (Aruba) to 24 points (Marshall Islands).


Stars aren’t even remotely similar in size or temperature. Among observed stars, the largest are up to 60,000,000 times larger that the smallest, and surface temperature can range by over 65,000 degrees Fahrenheit.


You know that Moby song “We Are All Made of Stars”? It’s true. The carbon, oxygen, nitrogen, and all other elements in your body came from the end-of-life explosions of stars long ago, which ejected these heavier elements into space for the raw material of younger stars, planets, people, and about everything else we see.