What happens if a gamma-ray burst hits Earth?
With the gamma-rays beamed directly at Earth, the radiation would destroy a significant portion of our atmosphere, specifically the ozone layer. The photons streaming from the burst would cause chemical reactions leading to photochemical smog. This would further deplete our protection from cosmic rays.
How long does a gamma-ray burst last?
Long-duration bursts last anywhere from 2 seconds to a few hundreds of seconds (several minutes), with an average time of about 30 seconds. They are associated with the deaths of massive stars in supernovas; though not every supernova produces a gamma-ray burst.
How do gamma rays affect the environment?
Gamma rays from space are absorbed by Earth’s atmosphere. They can destroy living cells, produce mutations, and cause cancer.
How long does a burst last?
Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived “afterglow” is usually emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).
What causes a long gamma-ray burst?
Most gamma-ray bursts are thought to be the result of huge stellar explosions – supernovae – in distant galaxies. They typically flash into being, shine for milliseconds or last several minutes, and then leave behind what astronomers refer to as an afterglow.
What would happen if a gamma-ray burst hit the Earth?
A nearby gamma-ray burst, beamed directly at Earth, is pretty unlikely. However, if one did occur, the amount of damage would depend on how close the burst is. Assuming one occurs in the Milky Way galaxy, but very far away from our solar system, things might not be too bad.
How rare are gamma ray bursts in the Milky Way galaxy?
Gamma-ray bursts in our Milky Way galaxy are indeed rare, but the scientists estimate that at least one nearby likely hit the Earth in the past billion years. Life on Earth is thought to have appeared at least 3.5 billion years ago.
How dangerous are gamma rays to humans?
These are among the most deadly radiation known. If a person happened to be near a gamma-ray producing object, they’d be fried in an instant. Certainly, a gamma-ray burst could affect life’s DNA, causing genetic damage long after the burst is over.
Did a gamma-ray burst cause the Ordovician extinction 450 million years ago?
Scientists say that a gamma-ray burst might have caused the Ordovician extinction 450 million years ago, some 200 million years before dinosaurs. Image Credit: NASA Click here for a 20 meg print-resolution version of this image