Scientists find evidence of another asteroid impact that may have killed dinosaurs

Scientists now think that a second asteroid may have hit Earth when the dinosaurs died out.

About 66 million years ago, an asteroid slammed into what is now the Gulf of Mexico, wiping off dinosaurs from the face of Earth. Now, scientists think that Earth was hit by another asteroid on the same day.

Scientists have found the "Nadir Crater" about 400 kilometres off the coast of Guinea, west Africa. The crater sits about 300 metres below the seabed and has a diameter of 8.5 kilometres.

It appears that the asteroid that may created the impact was under half a kilometre across. Identified by Dr Uisdean Nicholson from Heriot-Watt University, Edinburgh, UK, the crater was discovered by analysing survey data.

Nicholson was looking at seismic survey data to better understand how climate changed on Earth in the past. In conversation with BBC News, Nicholson described these surveys as "an ultrasound of Earth."

The primary asteroid that killed dinosaurs is said to be about 12 kilometres across. With a 200 kilometre wide-depression, this asteroid caused insane tremors, tsunamis, and firestorms around the globe.

The new asteroid, scientists think would have generated a kilometre-high tsunami along with an earthquake of magnitude 6.5 or higher.

Even with the similarities of age, the team is still wary of relating both the asteroids. Until samples are taken from the crater to prove that it is actually from an asteroid impact, we wouldn't know the full story.