They can exist for billions of years before dying and expelling their key ingredients into space.
They used scanning electron microscopy, secondary ion mass spectrometry and noble gas mass spectrometry, looking for the effects of exposure to cosmic radiation, which can penetrate solid material such as meteorites and leave its mark on the silicon carbide grains.
Co-author Jennika Greer, a graduate student at the Field Museum and the University of Chicago, said: "Once all the pieces are segregated, it's a kind of paste, and it has a pungent characteristic - it smells like rotten peanut butter". That's because plate tectonics, volcanism and other planetary processes heated and transformed all the presolar dust that may have collected during Earth's formation, said lead study author Philipp Heck, the Robert A. Pritzker Associate Curator of Meteoritics and Polar Studies at the Field Museum of Natural History in Chicago.
The discovery could give us an insight into how stars form, scientists believe, based on tiny grains dating from before the Sun formed.
Meteorites, if they don't collide with too much, can act as time capsules of trapped materials, like star dust.
Each individual grain of stardust has a chemical composition unique to the parent star it came from. Fragments of the meteorite totaling 100 kg (220 lb) were found across an area of over 13 sq km (5 sq mi).
But the Field Museum has most of the Murchison meteorite, a treasure trove of pre-solar grains that fell in Victoria, Australia, in 1969.
This "meteorite-rotten peanut butter paste" was then dissolved with acid, until only the presolar grains remained.
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"It's like burning the haystack to find the needle", says Heck. By figuring out the number of new cosmic-ray produced elements, researchers were able to measure the duration of exposure and date the presolar grains.
"Some of these cosmic rays interact with matter and form new elements", said Heck. I compare that to putting a bucket in a rainstorm. "Assuming the rainfall is constant, the amount of water that accumulates in the bucket tells you how long it was exposed", he adds.
Measuring how numerous new elements are present tells scientists how long the grain was exposed to cosmic rays.
This ancient interstellar dust, made of presolar grains (dust grains that predate our sun), was belched into the universe by dying stars during the final stages of their lives.
When the first stars died after two billion years of life they left behind the stardust, which formed into the block which fell to earth as the meteorite in Australia.
Stardust got on the chondrite, not our Solar system was formed.
While some astronomical models assume stars form at a constant rate, Dr Heck and his colleagues' work shows that isn't the case. "But thanks to these grains, we now have direct evidence for a period of enhanced star formation in our galaxy seven billion years ago with samples from meteorites".
The findings through the study being posted within the clinical diary Proceedings for the National Academy of Sciences (PNAS).