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Nirgal Valles stereopairs

These stereopairs show Martian canyons in the Nirgal Valles region, based on Mars Global Surveyor photos (MOC narrow-angle image M19-00386 Nirgal Vallis traverse, and MOC narrow-angle image E23-00175). Mars Unearthed has already produced a high-quality anaglyph of Nirgal Valles bedforms, but this page is for those who don't have red-blue glasses.

The aim is to demonstrate that the type of terrain misinterpreted as positive relief - the 'glass worms' of Richard Hoagland - actually has negative relief. Choose which stereo format you're more comfortable with. When properly focused (you can check by the craters being hollow rather than mounds) you'll see that the ribbed features are deep canyons with duned, slightly concave floors - not worms. Both images are about 110K.

Relaxed eye stereopair       Crossed eye stereopair

For further debunking of this and other Hoagland claims, visit Phil Tait's excellent Bad Astronomy site.

Image source: NASA/JPL/Malin Space Science Systems.

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