stratigraphy Archives

October 22, 2024October 22, 2024 by Evan Gough

This Early Impact Devastated Life then Gave it a Boost

This graphic depicts what happened when the S2 meteorite struck Earth about 3.26 billion years ago. Initially, it was devastating but eventually it lead to mass blooms. Image Credit: Drabon et al. 2024.

Most of us know about the impact that wiped out the dinosaurs about 66 million years ago. It’s a scientific fact that’s entered mainstream knowledge, maybe because so many of us shared a fascination with dinosaurs as children. However, it’s not the only catastrophic impact that shaped life on Earth.

There was an even more ancient one about 3.26 billion years ago, and its repercussions shaped early life in a unique way.

November 3, 2022November 3, 2022 by Evan Gough

Scientists Piece Together the Shoreline of an Ancient Ocean on Mars

Stitched together from 28 images, this view from NASA's Curiosity Mars rover was captured after the rover ascended the steep slope of a geologic feature called "Greenheugh Pediment." In the distance at the top of the image is the floor of Gale Crater, which is near a region called Aeolis Dorsa that researchers believe was once a massive ocean. The layered structure of the rocks indicated they were created by waterborne sediment. Credit: NASA/JPL-Caltech/MSSS.

Scientists have long suspected that Mars was once warm and wet in its ancient past. The Mars Ocean Hypothesis says that the planet was home to a large ocean around 4 billion years ago. The ocean filled the Vastitas Borealis basin in the planet’s northern hemisphere. The basin is 4–5 km (2.5–3 miles) below Mars’ mean elevation.

A new topographic map of Mars reinforces the hypothesis and adds more detail.