Sharks have an uncanny ability to sense tiny electrical fields. It helps them home in on prey. A new electronic sensor now mimics that ability — and works in saltwater.

This young pulsar — or spinning, ultradense star (large white dot in center right) — is not far outside our Milky Way. Some details of such celestial bodies are not visible. They come only from radio transmissions, which can be masked by Wi-Fi signals on Earth.

This illustration shows a robotic device, created by researchers in Israel, crawling through the intestine. The robot, which is about 2.5 centimeters (one inch) long, has a smooth surface so it can move through the stomach and intestines harmlessly.