Comets, Asteroids, Meteors, Oh My!

We use these terms somewhat interchangeably but, like most words, they each have a particular and somewhat different meaning. This may be worth learning about since we often have encounters with these objects as they travel through and around our solar system.Some of these encounters would not be so fun... just ask the dinosaurs.

On the other hand, some are very welcome and have an important place in culture. For instance, the famous Halley comet travels past us every 76 years and its passing has been a celebrated event by the people of Earth since the year 240 BCE.

Asteroids may not be as pretty, but are certainly worth looking out for. In fact, asteroid DA14 is due to pass by Earth on February 15th 2013 so close to the planet that it will actually be closer than our orbiting satellites.

Meteors may be the most important term for us to be familiar with. Here is an example of the effect a meteor can have on us. This is the Barringer Meteor Crater in Arizona which is about a mile in diameter and was formed by a meteor only about 150 ft wide.

See what you can find out about asteroids, comets, meteors, etc. Post a comment that describes their differences, warns of a future NEO (Near Earth Object) that we should worry about, details interesting information, or asks a question for which you can't find an answer.

Tyson, The Universe, and Black Holes

Neil deGrasse Tyson is the director of the Hayden Planetarium and an astrophysicist. He is also funny, eloquent, and entertaining. Here is a list of 10 things we should all know about the universe that Tyson likes to talk about. Below are two videos. In the first Tyson answers a question from a 2nd grader: "What would happen if two black holes collided?" Below that is another video describing falling into a black hole. Tyson is brilliant and funny, watch the clips on youtube so that you can check out some of his related talks. Lastly, there is another Symphony of Science video called "Onward to the Edge" which is my favorite. If you can't take Tyson talking then listen to him sing with autotune!

We Are Stardust

We are all star dust, literally. You are a star! So am I, so is everyone else and everything you see. We all came from stars. They were the furnaces that produced the ingredients of life and everything else on Earth. Here is how:

Now to put a perspective on how big these furnaces are:
 
And lastly, for some light entertainment!

What have you found out about stars that is interesting? Where do they come from? How long to they last? What happens when they die? What is going to happen to our sun?

By the way, if you want to see some incredible pictures of our universe/space/etc check out NASA's Astronomy Picture of the Day.

Eratosthenes

So about 2,300 years ago Eratosthenes figured out the circumference of the Earth. He thought it was 25,000 miles but was WAAAAAAAAY off. The actual circumference of the Earth is really 24,901.55 miles. Incredibly, even then he was only off by about 0.3%.