At least seven spherule beds have been found that formed between 3.23 and 3.47 Gyr ago, four between 2.49 and 2.63 Gyr ago, and one between 1.7 and 2.1 Gyr ago5,6,7,8,9. Here we ...

Spherule layers preserved in the geologic record accordingly provide information about an impact even when the source crater cannot be found1.

The millimeter-scale gray circles are all formerly molten droplets ejected into space when an asteroid struck the Earth about 2.56 billion years ago. These droplets, known as impact spherules ...

Spherule layers — such as the one shown in this 5-centimeter, 2.6-billion-year-old sample from Australia — are markers of ancient collisions. Advanced Search Home ...

The team are now working to link the spherule-rich texture observed at St. Pauls Bay to the wider stratigraphy at Witch Hazel Hill, and initial observations have provided tantalizing indications ...

The total length of viral filaments within the spherules was measured, revealing an approximate length of 18,600 ± 2900 Å and 21,400 ± 1600 Å per spherule (Figure 2B), which is equivalent to ...

Sir David, 95, recalled the “electric moment” when tests showed the chemical profile of a “spherule” matched that of the asteroid. “It was a moment of justification for the whole thing ...

A fragment of the rock may also have been found, preserved within a tiny "spherule" of clay, at the Tanis fossil site in North Dakota that the TV show is centred around.