Gamma Rays - NASA Science (2024)

FAQs

How does NASA use gamma rays? ›

Gamma rays sent out by objects embedded inside galaxies greatly affect the space around these objects and how these galaxies evolve. By studying gamma rays, NASA can better understand how the laws of physics work in the extreme environments found in the distant universe.

Gamma rays originate from the settling process of an excited nucleus of a radionuclide after it undergoes radioactive decay whereas X-rays are produced when electrons strike a target or when electrons rearrange within an atom.

In October 2022, an international team of researchers, including Northwestern University astrophysicists, observed the brightest gamma-ray burst (GRB) ever recorded, GRB 221009A. Now, a Northwestern-led team has confirmed that the phenomenon responsible for the historic burst — dubbed the B.O.A.T.

These are produced by spectacular events in the Universe such as stars exploding, matter falling into black holes and celestial objects colliding. By collecting gamma rays, astronomers are able to see these violent events and can judge exactly how they shape the Universe.

Gamma rays are ionizing electromagnetic radiation, obtained by the decay of an atomic nucleus. Gamma rays are more penetrating, in matter, and can damage living cells to a great extent. Gamma rays are used in medicine (radiotherapy), industry (sterilization and disinfection) and the nuclear industry.

But gamma rays are useful to humans in many other ways! They are used in the medical industry. They are used in manufacturing. They are sometimes even used in the food processing industry.

Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them. Gamma rays can pass completely through the human body; as they pass through, they can cause ionizations that damage tissue and DNA.

The gamma radiation from a burst within a few kiloparsecs would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar UVB radiation reaching the surface. This radiation is harmful to life, damaging DNA and causing sunburn.

Shielding: Barriers of lead, concrete, or water provide protection from penetrating gamma rays. Gamma rays can pass completely through the human body; as they pass through, they can cause damage to tissue and DNA. and x-rays. X-rays are capable of passing completely through the human body.

Fortunately, astronomers think that the chances of a gamma ray burst happening in our celestial backyard is slim: Since there are no stars within 200 light years of Earth that are fated to erupt in a gamma-ray burst, it's unlikely that we'll ever be in close enough range to suffer the consequences.

Could humanity survive a gamma-ray burst? ›

This ultraviolet radiation could potentially reach dangerous levels depending on the exact nature and distance of the burst, but it seems unlikely to be able to cause a global catastrophe for life on Earth. The long-term effects from a nearby burst are more dangerous.

The most powerful events in the known universe – gamma-ray bursts (GRBs) – are short-lived outbursts of the highest-energy light. They can erupt with a quintillion (a 10 followed by 18 zeros) times the luminosity of our Sun. Now thought to announce the births of new black holes, they were discovered by accident.

If you could see gamma-rays, the night sky would look strange and unfamiliar. The familiar sights of constantly shining stars and galaxies would be replaced by something ever-changing. Your gamma-ray vision would peer into the hearts of solar flares, supernovae, neutron stars, black holes, and active galaxies.

Gamma rays are the most harmful external hazard. Beta particles can partially penetrate skin, causing “beta burns”. Alpha particles cannot penetrate intact skin. Gamma and x-rays can pass through a person damaging cells in their path.

Aboard the space station, the use of hydrogen-rich shielding such as polyethylene in the most frequently occupied locations, such as the sleeping quarters and the galley, has reduced the crew's exposure to space radiation.

Examples of gamma rays are found in radioactive decay of naturally-occuring radionuclide, lightning (terrestrial gamma-ray flashes), and nuclear explosions. Gamma rays are also found in black holes, supernova remnants, and gamma-ray bursts.

Occasionally, giant explosions, called solar flares, occur on the surface of the Sun and release massive amounts of energy out into space in the form of x-rays, gamma rays, and streams of protons and electrons. This is called a solar particle event (SPE).