Visit the stingray tank at feeding time and get a closer look at these creatures made up completely of cartilage.

You've probably seen what a stingray looks like from above, but have you ever seen the underside where their mouth and nostrils are?

It's breakfast time at the South Carolina aquarium's stingray tank.

Visit the stingray tank at feeding time and get a closer look at these creatures made up completely of cartilage.

You've probably seen what a stingray looks like from above, but have you ever seen the underside where their mouth and nostrils are?

A quarantine exam is part of the San Diego Zoo's routine preventative health program. See what goes on behind the scenes.

See what's involved as penguins go through a quarantine exam before they're cleared to join their friends in a new exhibit.

It's important for handlers to be aware of any underlying health issues before animals begin their residency at the zoo.

Veterinary residents at the San Diego Zoo perform a routine quarantine exam.

It's breakfast time at the South Carolina aquarium's stingray tank.

How

The routine quarantine exam will make sure these endangered African penguins are healthy as they transfer to a new exhibit.

You've probably seen what a stingray looks like from above, but have you ever seen the underside where their mouth and nostrils are?

Visit the stingray tank at feeding time and get a closer look at these creatures made up completely of cartilage.

An unusual x-ray signal from the Helix Nebula, first detected in 19180, could stem from a star destroying a nearby planet. Credit: NASA/CXC/A. Hobart

On April 27, 1961, NASA launched Explorer 11, a satellite that contained the first gamma ray telescope to go to space. This marked the birth of space-based gamma ray astronomy. Gamma rays are a form of electromagnetic radiation and have...

Check out an amazing view of star cluster NGC 602. It "lies on the outskirts of the Small Magellanic Cloud," according to the Chandra X-ray Telescope team. Credit: NASA/CXC/A. Hobart

Scientists have discovered a mysterious pulsating light—and they don’t know what it could be. It pulses at a rate of about once every 21 minutes, and has been doing so since at least 1988. It doesn’t nicely fit the description of any of...

Veterinary residents at the San Diego Zoo perform a routine quarantine exam.

It's breakfast time at the South Carolina aquarium's stingray tank.

It's breakfast time at the South Carolina aquarium's stingray tank.

Veterinary residents at the San Diego Zoo perform a routine quarantine exam.

Visit the stingray tank at feeding time and get a closer look at these creatures made up completely of cartilage.

The Chandra X-ray Observatory was launched on July 23, 1999 aboard Space Shuttle Columbia. See 25 'never-before-seen' images from the observatory to mark the anniversary. <b<br/>r/>

Credit: NASA/CXC/A. Hobart