so there are good reasons why there is discussion now that we might be in a sixth mass extinction." Getty Images When space objects hit the Earth they can release the carbon held in rock very ...

Scientists have analysed ancient rocks and have found traces ... Sun and leading to rising levels of carbon dioxide. This would have triggered a major mass extinction: animals including vast ...

Carbon (C): Carbon, a nonmetallic element ... second most abundant element in the earth's crust and can be found in rocks, sand and clay. It acts as a deoxidizer in steel production.