Scientists have found organics from Earth's swamp trapped inside of glass created by a meteor impact almost a million years ago. The tiny pockets, only micrometers across, contain material such as cellulose and proteins. Though the impact glass was found on Earth, scientists say that similar samples could have been thrown into space by this or other blasts, allowing organics to be transported from one planet to another.
Approximately 800,000 years ago, a rock 100 to 160 feet (30 to 50 meters) across crashed down in Western Tasmania, Australia. As it slammed into the Earth, temperatures exceeded 1,700 degrees Celsius (3,100 degrees Fahrenheit), melting rock and creating glass sphericals, as well as a quarter-mile wide hole known as the Darwin Crater.
"The reason the glass is so abundant seems likely to relate to the presence of volatiles like water at the surface when the impact occurred," lead author Kieren Howard of the City University of New York told Astrobiology by email.
"A bit like when water from your spatula drips into a frying pan, having the right amount of water at the surface during impact may have increased the magnitude of the explosion, and the production and dispersal of the melt." (When Space Attacks: The 6 Craziest Meteor Impacts)
In Tasmania, the land was covered by swamps and rainforest, offering sufficient water to create the glass. According to the authors, glass from the Darwin Crater is the most abundant and widely dispersed impact glass on Earth, relative to the crater's size, with glass scattered across 150 square miles (400 square kilometers). In fact, the widespread glass led to the discovery of the crater, which is now filled with younger sediments, in 1972.
Varying types of glass form from impacts, depending on the rocks laying at the surface. Darwin contains quartz-rich rocks that create white colors, though other rock mixes in to create different shades.
"The greater the proportion of shale molten to make the glass, the darker in color it gets — from white through light green, dark green, to black," Howard said.