Lecture Recap

"Cosmic Collisions"
Thomas G. Bullen, CFC Memorial Lecture Series in Science and Technology 
Thursday, March 4
The Christopher J. Murphy Auditorium, Murphy Center
Dr. Heidi B. Hammel Senior Research Scientist and Co-Director of Research at the Space Science Institute (Boulder, Colorado).

"Cosmic Collisions"
On Thursday, March 4 Heidi B. Hammel, PhD, gave a presentation to the students of Iona College on "Cosmic Collisions"in the The Christopher J.Murphy auditorium, Murphy Center. Dr. Hammel is a Senior Research Scientist and Co-Director of Research at the Space Science Institute in Boulder, Colorado.

The presentation began with Hammel discussing that a comet is a ball of ice with dust mixed inside of it. She spoke about a comet that was discovered in March of 1993 on Jupiter. This comet became known as Comet-Shoemaker-Levy 9 and was the ninth one to be found. Hammel stated that a small comet appears every 500 years while larger ones appear every 6, 000 years. The last one to be seen was as recent as this past summer on July 19.

Hammel showed an illustration of impact sites on earth. There were no creators found in the ocean or on the Himalayan Mountains, but many craters are found in Australia due its desert-like climate. She stated that there were two types of Low Altitude Airbursts that can occur. One is an explosion that generates a fireball and descends rapidly, but doesn't reach the ground. Most of the damage at ground level is mechanical due to blast wave occurs for explosions. The second is a much larger fireball that would descend all the way to the surface. One example she gave was the Tunguska meteor. This was estimated to be as large as 3-20 megatons. They were able to figure out more about this comet by the treefall pattern and distribution, creating barograph and seismic data to learn more about it.

Hammel proceeded to discuss what researchers have done to prevent disasters from impacting earth. She explained that PHA stands for potentially hazardous asteroids and NEO's are near earth objects. Hammel explained that NASA's Space Guard goal is to find 90% of NEA's. In 2006 they recorded 4,500 asteroids that were NEA's. Researchers can find these asteroids by using a large synoptic survey telescope. This telescope has the ability to map out more objects in space.

Hammel made this learning experience very enjoyable for all the students that attended. She shared such interesting knowledge through her enthusiastic attitude about the subject, which was very appreciated by the students. Junior Jackie Tomcza, Psychology major, said "Although I am only taking one science course this semester, I felt that this event was a good learning opportunity for me."

Junior Lauren Casey, Advertising major, also commented with "I am not a science major and I still found the presentation extremely interesting. Dr. Hammel was incredibly informative and had me eager to hear more. I would have never guessed I would be so intrigued with this subject."

- Reported by Johanna Younghans, a student in Writing for Public Relations (Natalie Redcross, PhD).