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Asteroids  :  Big  Rocks  That  Really  Rock!

Asteroids - Big Rocks That Really Rock!

Contributed By : Bill Kochman

Please click on any link below to display a larger image.

Boulders - Atacama Desert, Chile

Boulders - Atacama Desert



Granite Boulders, Namibia

Granite Boulders

The Devils Marbles, Australia

The Devils Marbles
Australia 01

The Devils Marbles
Australia 02

Devils Tower, Wyoming, USA

Devils Tower
Wyoming, USA

Uluru / Ayers-Rock, Australia

Uluru / Ayers Rock

El Capitan, Yosemite

El Capitan
Yosemite National Park

Asteroid Vesta

Asteroid Vesta

Asteroid Ceres

Asteroid Ceres

Asteroid 243 Ida

Asteroid 243 Ida
I have a confession to make. I like rocks. More specifically, I like big rocks. In fact, I like very big rocks. No, I don't have rocks in my head; or at least I don't think so.

Whether it is a large rock which has had its surfaces rounded and smoothed after tumbling down a stream for more years than I have probably been alive, or a group of large boulders which have become precariously balanced over a long period of time through the natural forces of the Earth -- primarily wind and water -- or a majestic granite monolith like El Capitan rising from the forested floor of Yosemite National Park, or an awesome igneous intrusion such as Devils Tower in Wyoming, or the oddity of a huge red rock structure that sticks out like a sore thumb in Australia that is known as Uluru or Ayers Rock, big rocks simply impress me with their majesty and beauty. They seem to beg for admiration.

I don't know why, but I just seem to like big things: a huge boulder that weighs tons, a towering mountain with its sheer granite walls, a huge snake, a giant manta ray swimming gracefully in the Pacific Ocean, a great Blue Whale making its yearly migration. The bigger something tends to be, the more I am impressed.

But my attraction to big things is not just limited to the Earth. Oh no; I have my favorites in Outer Space as well, such as asteroids, for example.

Exactly what are asteroids? Derived from the Greek words "astēr" meaning "star", and "asteroeidēs" meaning "starlike", asteroids -- which are also sometimes referred to as planetoids -- are a large group of Solar System objects which for the most part inhabit a region of Space between the planets Mars and Jupiter -- and are thus referred to as main-belt asteroids -- although some possess an orbit that is closer to our planet, while still others are located deeper in Space. Composed of ice, rock and metal, or a variation of the same, they are believed to number in the millions.

Insofar as asteroids are concerned, currently, the star of the show for NASA is a giant asteroid by the name of Vesta. With an average diameter of 530 kilometers -- or about 330 miles -- Vesta is the second largest asteroid in our Solar System. That makes it larger than my home state. If you really want to be impressed, consider visiting the links to the NASA website below. Both links will take you to a video animation and narration concerning Vesta:

Vesta Video 01

Vesta Video 02

If you like this big rock as much as I do, then I also invite you to download a 1280p QuickTime version of the video narration. It is just over 26 MB in size, and is quite impressive. To download the video to your computer, please use the following URL. If you are on a Macintosh computer, after entering the URL in your web browser's location field, press and hold down the option key BEFORE hitting your return key. This will initiate the download.

1280p Narrated Video of Asteroid Vesta

Please note that in October 2011, the Dawn Mission spacecraft made an even closer approach to Vesta, which promises to provide us with images with a resolution that is eight times greater -- meaning more detail -- than the currently available videos of Vesta. You may want to keep abreast of news on NASA's Dawn Mission website in order to determine when the new videos will be available. No doubt, they will be spectacular. To access the Dawn Mission website, please use the following link:

Size-wise, Vesta is exceeded only by Ceres. With a diamter of 950 kilometers -- or 590 miles -- Ceres is currently the smallest known dwarf planet in our Solar System. Not only that, but it is also the only dwarf planet which inhabits the Asteroid Belt. To help you to understand exactly how big Ceres is, consider that one third of the total mass of the Asteroid Belt is taken up by Ceres alone. Now that the Dawn spacecraft has completed its mission at Vesta, it is heading to Ceres for humanity's second look at this asteroid. It is due to arrive around the beginning of December according the Dawn Mission website.

Another very interesting main-belt asteroid is 243 Ida, but it has nothing to do with its size. In fact, this asteroid is considerably smaller than both Vesta and Ceres, and has an average diameter of 31.4 kilometers, or 19.5 miles. However, 243 Ida holds the distinction of being the first asteroid to be found to have its own satellite, which you can see in the image to the lower left.

Naturally, in light of such Hollywood movies as "Deep Impact" and "Armageddon", many people wonder if the Earth is truly threatened by Space objects such as rogue asteroids. To further educate yourself concerning this matter, I invite you to visit the following pages on the NASA website:

Near Earth Object Groups

Target Earth

For the record, at this current time, there are 1,265 known PHA's, or Potentially Hazardous Asteroids. However, none of them currently pose any threat to the Earth. Potentially hazardous simply means that there may possibly be a threat at some point in the future. However, NASA officials assure us that even if there is a threat, we will probably have an advance notice of a few years, in order to take the necessary action to deflect the threat in some way.

For more information regarding asteroids, consider visiting the NASA website at the following URL:

NASA Asteroids Page

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