Typically, even the full Moon is approximately 400,000 times less bright than the Sun is, making it appear about 12–14 visual magnitudes dimmer to human eyes. While, in visible light, the Sun always outshines the Moon (due to the latter reflecting the former’s light), there is one part of the spectrum where the Moon can even outshine the Sun after all. (ROBERT ATANASOVSKI/AFP/GETTY IMAGES)

This Is The One Way The Moon Outshines Our Sun

If you think that the Moon is only good for reflecting sunlight, you’ve got another think coming.

To human eyes, the Moon is the second brightest visible object, trailing only the Sun.

As seen in X-rays against the cosmic background, the Moon’s illuminated (bright) and non-illuminated portions (dark) are clearly visible in this early X-ray image taken by ROSAT. The X-rays, like almost all wavelengths of light, arise mostly from reflected emission from the Sun. (DARA, ESA, MPE, NASA, J.H.M.M. SCHMITT)

Moonlight is just reflected light generated from other sources; it’s not self-luminous.

The size, wavelength and temperature/energy scales that correspond to various parts of the electromagnetic spectrum. You have to go to higher energies, and shorter wavelengths, to probe the smallest scales. Although the Moon reflects sunlight, the most energetic photons from the Sun normally top out at X-ray energies. (NASA AND WIKIMEDIA COMMONS USER INDUCTIVELOAD)

Across the whole electromagnetic spectrum, the Sun always appears much brighter than the Moon.

This 1991 photo shows the Compton Gamma-Ray Observatory being deployed in space during April 7, 1991 from the Space Shuttle Atlantis. This observatory was humanity’s first space-based gamma-ray satellite, and was part of NASA’s original great observatories program which included Hubble, Compton, Chandra and Spitzer. (NASA/KEN CAMERON)

Until, that is, we launched the , capable of measuring the highest-energy radiation.

A diagram of the EGRET instrument, which was used for observing the highest-energy photons aboard the Compton Gamma-Ray Observatory. The EGRET instrument is the only one capable of measuring photons with energies between about 20 MeV up to around 30 GeV: higher energy photons than the Sun typically emits. (NASA CGRO SCIENCE SUPPORT CENTER, NRA, APPENDIX G)