{"id":8018,"date":"2025-04-09T23:25:16","date_gmt":"2025-04-10T04:25:16","guid":{"rendered":"https:\/\/spaceengine.org\/?p=8018"},"modified":"2025-08-21T10:01:46","modified_gmt":"2025-08-21T15:01:46","slug":"opposition-surge-mini-post","status":"publish","type":"post","link":"https:\/\/spaceengine.org\/articles\/opposition-effect","title":{"rendered":"Opposition Surge (mini post)"},"content":{"rendered":"

In SpaceEngine, you may notice a bright reflection on some objects in the opposite direction of the sun (or other light source). This is neither a bug nor an unrealistic feature, but a real phenomenon called the opposition effect<\/strong> or opposition surge<\/strong>. The header image above shows opposition surge on Saturn's rings and a procedural planet in SpaceEngine (contrast increased for clarity).<\/p>\n

Opposition surge refers to the significant increase in brightness observed on many objects as their phase angle approaches zero (i.e. at opposition), when the observer is located directly between the object and the sun. Opposition surge can be observed on essentially all solid bodies in the Solar system, but is most prominent on rocky airless bodies and Saturn's rings. The effect is caused by a combination of shadow-hiding (particles on an object's surface blocking the view of their own shadows at zero phase), retroreflection (objects preferentially reflecting light back to the source due to their material properties and geometry) and coherent backscattering (constructive interference of reflected light waves back towards the light source). Shadow-hiding seems to be the main contributor in most cases.<\/p>\n

Scroll down for real-life images of opposition surge.<\/strong><\/p>\n

Moon<\/h4>\n

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\nOpposition surge on the lunar surface, centered on the shadow of Buzz Aldrin<\/em>
\nPhoto credit: NASA<\/em>
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