1. A new study in Iceland found identical twins aren’t 100% identical. On average, they have around five very small differences in their DNA that can affect things like how tall they end up as adults.
2. This would be great news if more research can back it up: A new study out yesterday found most people who get the virus have immunity for at least eight months. And it could last years.
3. A professor at Harvard thinks a weird, cigar-shaped object that passed by us in 2017 wasn’t an asteroid and might have actually been an alien probe to spy on us. It’s the first known object that’s entered our solar system from interstellar space.
4. Researchers can now tell if you’re listening to happy or sad music just by scanning your brain.
5. Today is “Earth’s Rotation Day,” the day a French physicist first showed how the planet rotates back in 1851. And in case you missed it, atomic clock experts just said this week that the Earth now is rotating slightly faster than it used to.
Because of it, days aren’t quite 24 hours right now. For example, Sunday was about a tenth-of-a-millisecond short. And we might need to add a “negative leap second” at some point, so it doesn’t mess with satellites that rely on perfect timing.