What's deep inside a comet
Comets are time capsules that hold clues about the formation and evolution of the solar system. They are composed of ice, gas and dust, primitive debris from the solar system's distant and coldest regions that formed 4.5 billion years ago. Deep Impact, a NASA Discovery Mission, is the first space mission to probe beneath the surface of a comet and reveal the secrets of its interior.
Here is a video of its approach to the comet.
Comet Tempel 1
Comet Tempel 1 was discovered in 1867 by Ernst Tempel. The comet has made many passages through the inner solar system orbiting the Sun every 5.5 years. This makes Tempel 1 a good target to study evolutionary change in the mantle, or upper crust. Comets are visible for two reasons. First, dust driven from a comet's nucleus reflects sunlight as it travels through space. Second, certain gases in the comet's coma, stimulated by the Sun, give off light like a fluorescent bulb. Over time, a comet may become less active or even dormant. Scientists are eager to learn whether comets exhaust their supply of gas and dust to space or seal it into their interiors. They would also like to learn about the structure of a comet's interior and how it is different from its surface. The controlled cratering experiment of this mission provides answers to these questions.
For more on the Deep Impact mission - http://www.nasa.gov/mission_pages/deepimpact/main/index.html
For more on Dawn: http://www.nasa.gov/mission_pages/dawn/main/index.html
I couldn't decide which to go with for D, so I chose both. Exploring the universe fills me with wonder. I'm so curious to know what's out there. What fills you with wonder?
Hosted by Arlee Bird of Tossing it Out http://tossingitout.blogspot.com/
