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原文:
If you could only see gamma-rays, photons with up to a billion or more times the energy of visible light, the Moon would be brighter than the Sun! That startling notion underlies this novel image of the Moon, based on data collected by the Fermi Gamma-ray Space Telescope’s Large Area Telescope (LAT) instrument during its first seven years of operation (2008-2015). Fermi’s gamma-ray vision doesn’t distinguish details on the lunar surface, but a gamma-ray glow consistent with the Moon’s size and position is clearly found at the center of the false color map. The brightest pixels correspond to the most significant detections of lunar gamma-rays. Why is the gamma-ray Moon so bright? High-energy charged particles streaming through the Solar System known as cosmic rays constantly bombard the lunar surface, unprotected by a magnetic field, generating the gamma-ray glow. Because the cosmic rays come from all sides, the gamma-ray Moon is always full and does not go through phases. The first gamma-ray image of the Moon was captured by the EGRET instrument onboard the Compton Gamma-ray Observatory, launched 25 years ago.
中文翻譯:
如果你只能看到 gamma 射線，即能量超過可見光上十億倍的光子，那麼月亮將會比太陽還要明亮！這一驚人概念是這幅圖像的基礎，這幅圖像基於在 Fermi Gamma-ray Space Telescope 的 Large Area Telescope (LAT) 儀器於 2008 至 2015 年間的數據。Fermi 的 gamma 射線觀測不會辨別月球表面的細節，但在假色圖中，與月球的大小和位置一致的 gamma 射線光芒顯然位於中心位置。最亮的像素對應於最顯著的月球 gamma 射線探測。為什麼 gamma 射線的月球如此明亮呢？高能帶電粒子不斷轟擊月球表面，這些粒子稱為宇宙射線，而月球沒有磁場的保護，因此產生了 gamma 射線的光芒。因為宇宙射線來自各個方向，因此 gamma 射線的月球始終是圓滿的，並且不會經歷相位變化。首幅 gamma 射線的月球影像是由 25 年前發射的 Compton Gamma-ray Observatory 上的 EGRET 儀器捕捉而來。
#GammaRayMoon #FermiTelescope #CosmicRays #SpaceScience #Astronomy #LunarGammaRays #ExploreTheUniverse #SpaceResearch #ScienceFacts #GammaRays
來源:NASA每日圖片
