Tucson Space Scientists Part of New National Geographic Special

Melosh, Pierazzo will talk on asteroid impacts, the most explosive events on Earth.
Feb. 12, 2009
Extra Info: 

"Known Universe"


6 p.m. - "Fastest"

7 p.m. - "Largest, Smallest"

8 p.m. - "Most Explosive"


Premier of "Known Universe" special
Feb. 15
National Geographic Channel
When an asteroid comes into the Earth's atmosphere, the first hint of impact is a blinding flash and then an enormous, deafening blast.
When an asteroid comes into the Earth's atmosphere, the first hint of impact is a blinding flash and then an enormous, deafening blast.

University of Arizona Regents' Professor of planetary sciences H. Jay Melosh and Elisabetta Pierazzo, a senior scientist at the Tucson-based Planetary Science Institute, are among several scientists featured in the National Geographic Channel’s new, three-part special, “Known Universe.”

The three-hour series focuses on the biggest, smallest, fastest and most explosive things in the universe. It is scheduled to air on the National Geographic Channel from 6-9 p.m. Tucson time on Sunday and slated to repeat at the same times on Thursday, Feb. 19.

Melosh and Pierazzo will appear in the a segment on the most explosive events in the universe.

Energy unleashed by the world's most powerful atomic weapons pales in comparison with the energy unleashed by earthquakes, volcanoes and hurricanes. But even these devastating natural events would be tiny compared with what would happen if a 6-mile-diameter asteroid slammed into Earth.

While pursuing their individual research programs, Melosh and Pierazzo have collaborated on modeling impact events on the Earth and other planetary surfaces. Both study the effects of impacts on the evolution of the environment and climate, and on the origin and evolution of life.

Melosh is considered one of the world's foremost experts on impact cratering and the importance of extraterrestrial impacts in shaping life on Earth.

Melosh discussed asteroid deflection, one of the strategies scientists have devised to harness the sun's power to divert a potentially dangerous asteroid on a collision course with Earth. Mirrors could be used to concentrate sunlight on an Earth-approaching asteroid and essentially turn the asteroid into a "solar rocket" headed away from Earth, Melosh said.

National Geographic interviewed Pierazzo, who also is an adjunct research scientist at the UA's Lunar and Planetary Laboratory, at Arizona’s Meteor Crater, the most well-preserved impact crater on the planet. The 3,000-foot-diameter, 570-foot-deep crater was formed when a boxcar-sized object crashed in northern Arizona’s desert about 50,000 years ago.

The Known Universe program on explosions is scheduled to begin at 8 p.m. The Known Universe program on the fastest things begins at 6 p.m. and the one on the largest and smallest things begins at 7 p.m.

The special combines the most current scientific information, cutting-edge computer graphics and everyday examples to shed light on some of the most mind-boggling aspects of our universe. Producers included computer-generated sequences, time-lapse sequences and slow-motion footage in the programs.