Educational Product
Teachers Grades 9-12
National Aeronautics and
Space Administration
Educational Brief
Subject: Iturralde Structure
Topic: Meteorite Craters


http://www.cs.purdue.edu/homes/krsul/pictures/Bolivia/mapa_grande.gif
 
The Iturralde Structure in Bolivia was discovered in 1985 but has yet to be analyzed on site. This structure, thought to be a meteorite impact crater, would represent the most recent meteor impact discovered to date.

The Iturralde Structure dates from 30,000 to 10,000 B.P. and, if from the younger end of the range, may be the youngest known complex impact structure on Earth. An expedition planned for October 1998 will attempt to determine the validity of the structure as an impact crater. The expedition team consists of meteoriticists, a communications specialist from Goddard Space Flight Center in Greenbelt, MD, and several biologists from Bolivia. The plan is to insert the team by helicopter for the approximately two week time period required for data accumulation.

The Iturralde Structure is located in an area with no roads and is approximately 250 km from the closest center with commercial air service. Terrestrial access has been possible only by river and on foot. An attempt to reach the structure in 1987 failed because of prolonged flooding in the pampas. Weather will be an important factor in determining the success of the 1998 mission.

Shane Keating, the GSFC communication specialist, will set up a link from the expedition that will allow audio and video interaction using the World Wide Web (WWW). The communication will be established through a laptop computer hooked through a satellite telephone. The satellite phone will relay the signal through Tracking and Data Relay Satellite System (TDRSS) to White Sands and then on to GSFC where it will enter the WWW. Schools will be able to be involved with the mission through the WWW. Questions from schools and feedback from the expedition will occur on the web site. In addition, schools selected by NASA will

receive soil samples from Iturralde for analysis using a specified protocol.

Dr. Peter Wasilewski, Goddard meteoriticist, emphasizes the importance of understanding impact processes and of meteor and meteorite research. As more knowledge of the planets and solar system is gained, it has become clear that impact processes have been a major player in the formation of planets and their moons. Earth’s moon is saturated with craters and Earth is thought to have experienced a similar impact rate.

The leading working hypothesis for formation of the moon involves a Mars-sized object colliding with Earth. Extinction of the dinosaurs and a massive die off of species is thought to be due to a major impact 65 million years ago. Amino acids have been found in some meteors and a Martian meteorite discovered in Antarctica is hypothesized to contain evidence of fossil bacteria.

Public interest in meteors and impacts has increased as evidenced by greater media coverage of impact structures as well as television specials and films centered around impact events. Unfortunately, the science depicted is often misleading or inaccurate.

GSFC NASA continues to engage in research of these events with implications for the following:

• formation and structure of the solar system and
Earth
• origin of life
• sustainability of life
•geologic events such as extinctions
•exploration of other planets
Authors: Ken Baxter and Bruce Taliaferro
Goddard Scientist: Dr. Peter Wasilewski <u1pjw@lepvax.gsfc.nasa.gov>