The Moon is actually brighter than the Sun
Cosmic rays are the high-energy radiation that comes from outside our solar system produced by things like supernovae and active galactic nuclei (AGN). They are nothing but protons accelerating through the universe, like blasts of waves of exploding stars. When these electrically-charged particles strike matter, say, the lunar surface, they turn into gamma rays.
Daily Current Affairs Quiz 2019
Gamma rays are created when electrically charged cosmic rays — protons accelerated by supernovae or jets produced by matter sucked into black holes — interact with matter, such as the surface of the moon.
They’re the most deadly type of EM radiation for living organisms. Luckily, they’re largely absorbed by Earth’s atmosphere.
However, on the moon, most of the gamma-ray radiation produced is absorbed by Earth’s natural satellite. Meanwhile, the sun only produces a fraction of its electromagnetic radiation in gamma rays — much less than the moon — because it has a very powerful magnetic field.
You can’t see gamma rays with the naked eye, but that’s where the Fermi Telescope comes in.
In a recent study, astronomers have calculated that the moon’s gamma rays can exceed 31 million electron volts, or 10 million times more powerful than visible light.
This brightness isn’t constant, though. Fermi LAT data show that the Moon’s brightness varies by about 20% over the Sun’s 11-year activity cycle.
Although the moon is much brighter in gamma rays than the sun, occasionally cosmic rays will strike the dense part of the sun’s atmosphere, resulting in gamma rays above one billion electron volts. In this range, the sun is actually brighter.
The findings suggest that astronauts visiting the moon or living there over extended periods in a lunar outpost would be a great risk. Gamma rays and cosmic rays have a great penetrating power, which means shielding using elements such as lead is paramount.
NASA plans on sending humans back to the moon in 2024 as part of its Artemis program. Before that happens, we will have to be prepared for the threat of radiation exposure.
What is Gamma ray ? A gamma ray, or gamma radiation, is a penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves and so imparts the highest photon energy.