|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
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. Earths
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
- origin of life
sustainability of life
geologic events such as extinctions
exploration of other planets