Randoms.

Since this will be my last blog post for this class, and I couldn't decide on what to write about, I am just going to write random stuff and hope it goes well. :) First of all, I really enjoyed this class. I found it extremely interesting, and hope I get the chance to take another course on astronomy sometime in the future. I've learnt SOOO much about Star, Galaxies, and the Universe, and had a blast doing it. My interest in astronomy has risen quite a bit, and is now more of a hobby. Here are some random things I found interesting on the internet:

This is a video that I thought was really cool. The pictures were taken by NASA, and the music is by Eric Idle.
http://dingo.care2.com/cards/flash/5409/galaxy.swf

the 10 craziest scientific theories.
http://listverse.com/2010/07/12/10-craziest-scientific-theories/

Amazing pictures taken by the Hubble telescope.
http://www.presidiacreative.com/40-mind-blowing-hubble-astrophotographs/

Cassini-Huygens.

The Cassini spacecraft was launched on October 15th, 1997 from Cape Canaveral, located in Florida. Cassini is considered one of the most complex interstellar spacecrafts ever built. There have only ever been 2 other spacecrafts that were heavier than Cassini, and they were sent to Mars by the former Soviet Union. It is 6.7 meters high and 4 meters wide, with a weight of 5,560 lb. This spacecraft is made up of 2 elements: The Huygens probe, and the Cassini orbiter. The structure of this spacecraft, and the powerful cameras it carries, helps send back to Earth accurate measurements, and detailed images.

Here is a list of Cassini's primary objectives. This information is from a website that will be posted at the bottom of this article.

1. Determine the three-dimensional structure and dynamic behavior of the rings of Saturn
2. Determine the composition of the satellite surfaces and the geological history of each object
3. Determine the nature and origin of the dark material on Iapetus's leading hemisphere
4. Measure the three-dimensional structure and dynamic behavior of the magnetosphere
5. Study the dynamic behavior of Saturn's atmosphere at cloud level
6. Study the time variability of Titan's clouds and hazes.
7. Characterize Titan's surface on a regional scale.

http://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

Mercury.

Mercury is the smallest planet in our solar system (Sorry Pluto), and the closest plant to the Sun. If you want an idea of just how small it is, think of its comparison to the Earth.  The Earth has a diameter of 12,742 km, while Mercury is only 4879 km, a little over 1/3 of the Earth's size. Mercury's volume is only around 0.05 of the Earth's, but still extremely dense (Approximately 5.4 grams per cubic centimeter), which consists of mostly Iron and rock. Earth is the only other plant with a density higher than Mercury, therefore, if Mercury were the same size as Earth, it would be much denser. 

Mercury orbits the Sun every 88 days. Mercury's appearance is similar to the Moon's, but unlike the moon, it has a large iron core that generates a magnetic field around 1% as strong as the Earth's. It was named after the Roman god "Mercury", the god of commerce, travel and thievery. This was probably because Mercury moves across the nighttime sky so fast. 

Hubble Space Telescope.

The Hubble Space Telescope (named after the famous astronomer, Edwin Hubble) is a telescope that orbits Earth at an orbital velocity of 7, 500 m/s with an orbit height of 559 km. It was carried into orbit on April 24th, 1990, by Space Shuttle Discovery. This telescope, which was built by NASA and the European Space Agency, is controlled by the Space Telescope Science Institute. Though Hubble cost $36 million, it has sent back thousands of images that have helped explain to us many mystery's of astronomy.

Hubble moves 5 miles per second when orbiting Earth, resulting in a 97 minute orbit period. It is a Cassegrain Reflector: A telescope that uses the light hitting its several mirrors to focus that light into a hole with science instruments on the other end. Telescopes collect more light than the human eye.
When Hubble slowly degrades and eventually stops working, it will continue orbiting Earth until it's fully decayed, at which point it will spiral towards Earth (and hopefully land in the ocean).

Space beer!

Have you ever asked yourself, "Can I consume beer in space?"
I'm sure you have. Well I have good news for you! YOU CAN!

You're probably thinking that any beer can be chugged in space, but this is INCORRECT! It would be expensive to launch it up there and it's a physical impracticality to consume a carbonated beverage in space. Why is this? Well, when you drink beer on Earth, it goes down your throat and sits in your stomach. Gravity is the reason the fluid stays in your stomach, allowing the carbon dioxide bubbles to expand and rise to the top of it. Normally, you'd releases these gases from your mouth.
In space, there is very little gravity to keep this liquid settled in your stomach, but the carbon dioxide expanding in your belly has to be released. You end up expelling everything in your stomach (Carbon dioxide, beer, etc.) through your mouth and nose. This is called a "wet burp."

An Australian company called " The 4-Pines Brewing Company" got together with Saber Astronautics Australia to create a beer that could be consumed in space, and tastes delicious. This beer, which is called "Vostok," is high in flavor and low in carbonation.

A shooting star.

GUESS WHAT!

A "shooting star" is not a shooting star! It's actually a broken fragment of a comet (Ice, dust, and rock,) that travels through space, orbiting the sun. When this piece of debris is in outer space it is called a meteoroid. Gravity will eventually pull the meteoroid into Earth's atmosphere, making it a meteor. As these fragments of rock fall into Earth's atmosphere, they will experience a buildup of frictional heat. The heat makes the particles of the meteor glow brightly as it continues to fall. Most meteors will burn up before they hit the Earth, but if they are large enough and make it to the ground, they are called a meteorite. When you are staring into the beautiful night sky and notice a streak of light pass by, you are looking at a "shooting star."

The largest meteorite was discovered in 1920 by a farmer in Namibia. It is nine feet long, nine feet wide, and three feet thick. "Hoba" weighs 66 tonnes, and is composed of 84% iron, 16% nickel. It currently resides in its original location of discovery.

The Sun.

98% of our total solar systems mass is taken up by the Sun, making it the largest object in the solar system. The Sun is around 70% Hydrogen, and 28% Helium. The last 2% is made up of "metals". This can slowly change over time as the Sun converts Hydrogen to Helium in its core (The inner 25% of its radius). The Sun produces power by Nuclear Fussion Reactions.

The Sun is approximately 4.5 billion years old, and has used up to half of the Hydrogen in its core. For the next 5 billions years it will continue to radiate, and it's luminosity will double in that time. Eventually, the Sun will run out of Hydrogen fuel and be forced into radical changes. This means that through commonplace by stellar standards, it will result in the total destruction of the Earth.