Hundreds of people took to Twitter over the weekend to post pictures of what looked like a UFO over California. Unfortunately for alien enthusiasts, the object in question was just one of SpaceX's Falcon 9 rockets.

Mary Beth Griggs, Associate Editor at Popular Science, explains what caused the spectacle in the sky. The reason this launch looked different from previous ones was a combination of humidity and cold air in the atmosphere.

Griggs also discusses what to do if your dog gets hold of your holiday chocolate over the next few weeks. Christmastime is when veterinarians see the biggest spike in chocolate incidents with dogs. Theobromine in chocolate is toxic to man's best friend and could be potentially lethal depending on how big the dog is, what kind of chocolate he ate, and how much.

If your dog gets his paws on holiday goodies, the first thing you should do is find out what chocolate they ate and how much. Get a hold of your vet, and they will be able to help you through the process from there. If you can't reach your vet, you can use an online chocolate dose calculator.