A day on Earth was a half-hour shorter just 70 million years ago

A day on Earth was just 23.5 hours long, 70 million years ago. Researchers discovered this by studying the growth rings of ancient mollusk fossils. The findings could tell us more about or planet and its relationship with the Moon. Visit BGR's homepage for more stories. A full day on Earth hasn't always been 24 hours long. A new study reveals that a day on our planet once lasted approximately 23.5 hours, and it wasn't that long ago that days were significantly shorter. The finding was made possi...