A study found that wildfires and oxygen-poor environments helped destroy 90 percent of life on Earth in less than 200,000 years.
Researchers have found that risk factors of stroke can also signal cognitive impairment.
NASA sent Curiosity, the world's biggest extraterrestrial explorer, on an eight-and-a-half-month journey to Mars Saturday in hopes of discovering evidence that the planet might have once been home to microscopic life.
A hacker released a second round of emails between climate scientists which portrayed them in a negative light last Tuesday, ahead of this week's gathering of United Nations negotiators in South Africa for the purpose of discussing a global climate pact.
-compiled by Surabhi Bhatt, Adnin Zaman and Faiza Arif