Impact: Ground Zero is an interactive multimedia presentation about comet and asteroid impacts on the Earth.

Impact has a feel of one of those great PBS TV specials that all of us love to watch, except it is much better! It offers interactivity, which TV shows can only dream of, and a reference library of documents and photos that you can explore at your own pace.

The Dinosaur Impact

Did the massive impact 65 million years ago lead to the extinction of dinosaurs?

First of all, was there a massive impact 65 millions years ago? The most compelling evidence that this impact did indeed occur is a layer of iridium found in sediments around the world. Dr. Frank Asaro, a nuclear chemist at the University of California Lawrence Berkeley Laboratory suggests an extraterrestrial origin of this iridium in a video interview.

So how exactly did the dinosaurs become extinct? Were there other species that also disappeared for good? Which animals, if any, survived? You can learn the answers to all of these questions from an engaging video interview with Dr. Kevin Zahnle - an astrobiologist at the NASA/Ames Research Center, also included in the Impact.

Astronomical Events

Impact features an interactive timeline of important astronomical events. From 65 million years ago to April 1997, when a mile-wide asteroid 1997XF11 was discovered.

'Astronomer Brian Marsden at the Harvard-Smithsonian Center for Astrophysics announced that [this] asteroid headed for Earth, claiming that it should come as close as 30,000 miles in the year 2028. Barely one day later, new data and calculations determined XF11 posed no danger - it was concluded that the asteroid will miss the Earth by 600,000 miles. It will be closer to the Earth than any other asteroid of that size, but 600,000 miles is still considered a comfortable distance.'

Comets, asteroids, meteors ...

With Impact you can learn more about comets, asteroids and meteors. What are they made of? What are typical sizes and masses of these objects? Also, you can browse an extensive photo library of these objects. Impact contains some of the most breath-taking photos.

Interactive Quiz

You are put in charge when a massive asteroid is heading to the Earth. Here is an example of a quiz question:

1. The use of ground-based lasers to deflect the asteroid's orbit
2. The firing of multiple missiles with nuclear warheads to intercept and destroy the asteroid before it makes its near-earth approach
3. To send an unmanned space vehicle to land on the asteroid and set nuclear charges at predetermined locations to divert the asteroid's orbit
4. Evacuate the impact site and move nuclear armaments triggered to go off immediately prior to impact, to neutralize the incoming asteroid

Reference Library

An extensive reference library of over 225 pages (PDF format) documents and photos is included with the Impact software. A collection for your reference and education, something you can print and learn from.

Interviews

Impact includes a number of video and phone interviews with leading scientists:

David Morrison - Director of Space, NASA/Ames Research Center
Kevin Zahnle - Astrobiologist, NASA/Ames Research Center
Clark Chapman - Institute Scientist, Space Studies Dept., Southwest Research Institute
Gregory Canavan - Scientist, Department of Physics, Los Alamos National Laboratory
Buck Sharpton - Senior Scientist, Lunar Planetary Institute
Mark Lee - Space Shuttle Astronaut, NASA/Johnson Space Center
Frank Asaro - Nuclear Chemist, University of California Lawrence Berkeley Laboratory
Jan Smit - Micro Paleontologist, School of Sedimentary Geology (NSG) Amsterdam, Netherlands
Jim Scotti - Senior Research Specialist/University of Arizona's Lunar and Planetary Lab, & Space Watch

Final Word

We found the Impact: Ground Zero to be an exceptional science software. It is well designed and executed. It contains a wealth of well structured information. Using this highly interactive software is 'time well spent'! At the price of $12.99, each and every student and school should have one.

Review by: Anton Skorucak, Editor-in-Chief, PhysLink.com