Curtin University planetary scientists have been selected by the Japanese Space Agency (JAXA) to undertake geochemical analysis of two of the largest and most precious grains that it recovered from the asteroid Itokawa.
The scientists hope to uncover the formation of the asteroid’s age and ultimately contribute new knowledge about the history of the solar system.
The grains have been recovered from the Hayabusa spacecraft, the first ever space mission to bring back samples from an asteroid, and will undergo argon analysis, a once-only destructive technique.
Dr Fred Jourdan and colleagues at Curtin’s Department of Applied Geology and John de Laeter Centre for Isotope Research, along with colleagues at the Western Australia Museum were recently awarded the grains by JAXA.
“This is a major achievement, in particular due to the fact that the argon technique can only be used on the biggest grains and is a destructive technique which means that these large grains will be vaporised using a laser beam and will not be available for further study,” Dr Jourdan said.
“However, argon analysis of grains from the surface of Itokawa will allow us to constrain the formation age of the asteroid and no other technique is more suited for this task.”
The technique involves the decay of potassium in argon and is used to measure the age of geological events such as volcanic eruptions or the formation of impact craters formation.
The grain samples were recovered in 2005 when JAXA, in collaboration with NASA, sent an unmanned spacecraft to study and sample the asteroid Itokawa. The Hayabusa space mission, the first mission to bring back samples from an asteroid, returned to Earth in June 2010 with about 1,500 tiny grains.
Dr Jourdan was awarded the grains because of the international standing of his laboratory in the study of meteorites and asteroid impacts, as well as the reputation of the John de Later Centre for Isotope Research, which is dedicated to research using mass spectrometer instruments.
Itokawa was believed to have formed recently following a major impact on an unknown parent asteroid. Dr Jourdan and his team will not only aim to date this major impact, but they will also measure the age of the surface of Itokawa by measuring how long the grains have been exposed to cosmic rays.
“We will also measure the argon composition of the solar wind implanted at the surface of the grains,” he said.
This is the first time argon chronology will be attempted on samples from a known asteroid. Usually, it is not known which asteroid a meteorite has come from.
Dr Fred Jourdan, Senior Research Fellow, John De Laeter Centre for Isotope Research, Curtin University
Mob: 0424 174 984; Email: F.Jourdan@curtin.edu.au.
Megan Meates, Public Relations, Curtin University
Tel: 08 9266 4241, Mobile: 0401 103 755, Email: firstname.lastname@example.org