An international team of scientists has examined dust grains gathered by the NASA Stardust spacecraft and brought back to Earth – and has discovered that they originated in the interstellar dust stream.
With the help of citizen scientists, the research team has identified seven dust particles and residues – less than 1 millionth of a metre across – that are consistent with interstellar dust, which they have documented in an academic paper entitled “Evidence for interstellar origin of seven dust particles collected by the Stardust spacecraft” and published in the journalScience.
Analysis of these particles is significant for increasing our understanding of what interstellar grains are made of, in order to better understand the complexities of the solar system’s formation. As interstellar matter is the substance that generates new stars and planetary systems, particles such as those discovered could serve as building blocks for future planets.
The study, which was led by Dr Andrew Westphal from Space Sciences Laboratory at University of California, Berkeley, was co-authored by Dr John Bridges from the University of Leicester’s Department of Physics and Astronomy and an international team of scientists.
The Stardust spacecraft used giant tiles made out of aerogel and aluminium foil to collect the dust samples. Aerogel is an extremely low density lightweight synthetic material, often described as ‘solid smoke’.
Dr Bridges explained: “Analysing the foils and aerogel from Stardust has taken a lot of time and effort involving researchers and Citizen Science, and we are now seeing the results of that work. We know from astronomical observations that there is a stream of particles that reaches our Solar System from interstellar space. Our results show us what this stardust – from which our Solar System formed – actually is.
“Some of these grains formed in suns predating ours, so we are looking beyond our own Solar System when we study them. We have also learnt a lot about how to collect and analyse these tiny grains, which are less than 1 millionth of a metre in size, which will be important in future missions.”
The preliminary findings of the study are based on an analysis of microscopic particles collected by NASA’s Stardust mission launched in 1999 to collect dust samples from the comet Wild 2 and return them to Earth for study. As part of the mission, Stardust’s ‘Interstellar Dust Collector’ was exposed to an interstellar dust stream coming from the direction of the constellation Ophiuchus, the Serpent Bearer.
Dr John Bridges’s research was supported by the Science and Technology Facilities Council (STFC).
ENDS
Notes to editors:
For more information contact Dr John Bridges on j.bridges@le.ac.uk
About the Science and Technology Facilities Council:
The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar.
STFC operates or hosts world class experimental facilities including in the UK the ISIS pulsed neutron source, the Central Laser Facility, and LOFAR, and is also the majority shareholder in Diamond Light Source Ltd.
It enables UK researchers to access leading international science facilities by funding membership of international bodies including European Laboratory for Particle Physics (CERN), the Institut Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF) and the European Southern Observatory (ESO).
STFC is one of seven publicly-funded research councils. It is an independent, non-departmental public body of the Department for Business, Innovation and Skills (BIS).
