The Whirlpool Galaxy (M51) offers a chance to see a galaxy collision occurring in the sky. Here's how to view this ...

The Joint Service General Purpose Mask (JSGPM) is a lightweight, protective mask system incorporating state-of-the-art technology to protect U.S. Joint forces from actual or anticipated threats.

Each of these submarines is equipped with 16 missile silos capable of launching the M51 submarine-launched ballistic missile (SLBM). The M51 missile, with its multiple independently targetable ...