I am sure that most people have heard NASA’s deep impact porject. It will be great if I can observe the event. Unfortunately, I will not be able to witness the event because I will be in LA at the moment the impact takes place.
Quote: 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.
On July 4, 2005, the Deep Impact spacecraft arrives at Comet Tempel 1 to impact it with a 370-kg (~820-lbs) mass. On impact, the crater produced is expected to range in size from that of a house to that of a football stadium, and two to fourteen stories deep. Scientists expect to see ice and dust debris ejected from the crater revealing fresh material beneath. A dramatic brightening caused by sunlight reflecting off the expelled material and the possible opening of a gas jet is anticipated. Images from cameras and a spectrometer are sent to Earth covering the approach, the impact and its aftermath. The effects of the collision with the comet will also be observable from certain locations on Earth and in some cases with smaller telescopes. The data is analyzed and combined with that from other missions, from telescopes around the world and in Earth orbit. These results will lead to a better understanding of both the solar system’s formation and implications of comets colliding with Earth.
To learn more, visit NASA’s Deep Impact Page or NASA’s flash introduction. Here is also a gallyery with videos & Animations that one may see how the process may look like.
Last, for those who have a [good enough] telescope and want to watch the event as it is happening, here is a "map" where the impact is going to take place at that night.
Image Source: PhysOrg.com