Deadly Blasts

The death of a star can produce some spectacular fireworks. The star blasts all or most of itself into space, shining as brightly as millions or billions of normal stars. And it can produce “jets” of energy that are the brightest outbursts in the universe.

Those fireworks would mean instant doom for any planet in orbit around the exploding star. But even planets that are many light-years away could suffer ill effects.

Such an explosion is known as a supernova. It can happen in one of two ways. One is when a massive star can no longer produce nuclear reactions in its core. The core collapses, and its outer layers blast into space. The other is when the dead core of a Sun-like star takes too much gas from a companion star. That triggers a nuclear blast that rips the star to bits.

Radiation from a supernova could endanger life on any planet within a few dozen light-years. It would strip away the planet’s protective ozone layer. That would allow more radiation to reach the surface -- perhaps enough to cause a mass extinction.

Some exploding stars produce jets of gamma rays, the most powerful form of energy. They blast from the poles of the exploding star as narrow beams. The beams could cause the same kind of damage as a supernova’s other forms of radiation, but at a range of thousands of light-years.

Fortunately, no likely future supernovae are anywhere close to Earth. So for now, we’re safe from these cosmic fireworks.

More tomorrow.

Script by Damond Benningfield