Here's why:

* Supernovas occur in massive stars. Our sun is a medium-sized star, about 1/10th the mass of stars that go supernova.

* Sun's fate: Our sun will eventually become a red giant, then a white dwarf. This process will take billions of years.

While the sun won't explode in a dramatic supernova, it will still eventually expand and engulf Earth. This will happen in about 5 billion years.