Barbara Cutler, assistant professor of computer science at Rensselaer

Lunar eclipses are well-documented throughout human history. The rare and breathtaking phenomena occur when the moon passes into the Earth’s shadow and seemingly changes shape, color, or disappears from the night sky completely.

Researchers at Rensselaer Polytechnic Institute have developed a new method for using computer graphics to simulate and render an accurate visualization of a lunar eclipse. The model uses celestial geometry of the sun, Earth, and moon, along with data for the Earth’s atmosphere and the moon’s peculiar optical properties to create picture-perfect images of lunar eclipses.

Looking Back and Looking Forward

The computer-generated images, which are virtually indistinguishable from actual photos of eclipses, offer a chance to look back into history at famous eclipses, or peek at future eclipses scheduled to occur in the coming years and decades. The model can also be configured to show how the eclipse would appear from any geographical perspective on Earth — the same eclipse would look different depending if the viewer was in New York, Seattle, or Rome. 

“Other researchers have rendered the night sky, the moon, and sunsets, but this is the first time anyone has rendered lunar eclipses,” said Barbara Cutler, assistant professor of computer science at Rensselaer, who supervised the study. “Our models may help with investigations into historical atmospheric phenomena, and they could also be of interest to artists looking to add this special effect to their toolbox.”