Iapetus illusions

Yesterday’s Astronomy Picture of the Day was a detailed image of Saturn‘s Moon Iapetus named after the Titan Iapetus from Greek mythology.

Iapetus

I cannot wrap my brain around that image. The craters all look like they bulge out to me. This is because the sunlight originates from below the scene but my brain insists that sunlight always originates from above a scene. Below is the same image rotated 180 degrees.

Iapetus

Much better.

The image was taken by the space probe Cassini – part of the Cassini-Huygens spacecraft launched on 15th October 1997. The Cassini part of the name was in honour of astronomer Giovanni Domenico Cassini who was the first to observe four of Saturn’s moons. He also discovered the Cassini division which is the main gap in the ring system. The Huygens part of the name is in honour of astronomer Christiaan Huygens who studied Saturn’s rings. In 1656 Huygens discovered they consisted of rocks.

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One Response to Iapetus illusions

  1. John Kennell says:

    Thank you for upside downing that for me. I can see it now… 🙂

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