Two European teams are participating in an all-star project
consisting of labs from all over the globe investigating the
origins of the solar system. The labs are studying space particles
collected by the spacecraft Stardust. Stardust was sent to
the edges of the solar system to collect material left behind
by the Wild 2 comet, which is presumed to have formed around
the same time as our system. Experts hope the dust contains
material from that time untouched by solar radiation. To help
analyse the ancient grains, samples have been sent across
the globe, including to the European Synchrotron Radiation
Facility (ESRF). Project findings were recently reported in
a special series in Science
Cometary and Interstellar Dust Analyser used to
collect ESRF samples.
Researchers have been carefully sifting through the contents
returned by the Stardust spacecraft over the past year looking
for vital information on the origins of the solar system. They
have been treating the samples with X-rays at ESRF and other
labs to produce imagines scientists use to determine the elements
embedded in the cometary material.
Scientists posit that planets and other interstellar bodies, such as comets, formed from a dense disc of gas rotating around a newly formed star. Since Wild 2 is believed to have originated in the Kuiper belt beyond Neptune, scientists believe it may have been spared solar radiation that can alter its characteristics. If they are correct, Wild 2 may contain material intact from the earliest stages of the solar system.
Stardust travelled 2.88 billion miles (4.63 billion km) during
its seven-year voyage to bring back the significant catch of
about one microgram of cometary dust. The samples have been
contrasted with meteorites found on Earth believed to be around
the same age, and have been found to contain similar minerals
and organic materials. Despite the similarities, the Stardust
samples possess properties not found in known samples, which
scientists expect will give them a glimpse into the development
of a nascent solar system.
For example, researchers have found compounds called Calcium
Aluminum-rich Inclusions that are believed to have been formed
inside the solar nebula. The finding suggests the material was
transported to the edge of the solar system where Wild 2 was
formed, challenging the widely-held belief that comets only
form beyond Jupiter's orbit.
Two hundred samples from the mission have been distributed around
the world to the 175 members of the Preliminary Examination
Team. Remaining samples will be preserved for future researchers
to be studied with novel tools as technology progresses.
Two European teams, one from the Institut d'Astrophysique
Spatiale in Orsay and The Ecole Normale Supérieur in
Lyon (France), and the other from the Universities of Frankfurt
(Germany), Antwerp and Ghent (Belgium), travelled to the ESRF
to carry out experiments on a total of 7 samples.