That well-worn science-fiction horror story of an asteroid ploughing into Earth may not be so catastrophic after all, according to researchers in Perth.
Scientists at Curtin University have discovered that an asteroid impact might actually preserve ancient ecosystems, rather than wipe out civilisation as we know it.
And the proof has been discovered in Tasmania, with new findings in the journal Nature Geoscience documenting amazing glass fragments produced by the massive impact at the island’s famous Darwin Crater.
The researchers believe that when large meteorites strike Earth – at speeds up to 18 kilometres a second – the energy released causes solid rocks to melt and blast into the air.
Droplets of molten rock then rain down over large areas, solidify in flight, and form glass fragments known as “impact glasses”.
A study of the material captured inside the glass suggests minute pieces of rainforest and swamp survived the extreme pressures and temperatures during the impact, and were preserved forever.
Professor Phil Bland, co-author and planetary scientist from Curtin’s Department of Applied Geology, compared the pieces of glass to tiny time capsules.
“Inside these glasses, the research team found tiny spheres of carbon bearing organic matter sourced from the ancient rainforest and swamp present at the time of impact,” Professor Bland said.
“Seeing well-preserved biomarkers in these very tough glasses is really exciting.”
Dr Kieren Howard, lead researcher and a mineralogist based in New York, said it had been assumed organic molecules would not survive a meteorite impact.
“The evidence we have now supports an old hypothesis that impacts might have delivered the building blocks of life to early Earth,” Dr Howard said.
While the discovery is significant on Earth, the researchers believe it could prove even more so elsewhere in the universe.
“On planets like Mars, impact glasses may survive billions of years, possibly providing evidence for long-extinct Martian organisms,” Professor Bland said.
“Impact glasses from Mars might be a great place to look for evidence of past life.”