Experts are scrambling to find out exactly what kind of bomb went off in North Korea on Wednesday. The detective work could take days or weeks as seismic waves are more closely analyzed and US and Japanese sniffer planes try to test atomic plume particles.
Most people agree that the Paris climate agreement is a good start toward curbing the worst impacts of climate change. But others worry too much self-congratulating will jeopardize the path toward stricter carbon cuts.
The Pinta tortoises of the Galapagos Islands have been extinct since the last one, Lonesome George, died in 2012. Now, scientists are trying to revive the species using hybrid descendants recently discovered.