Do we have any astronomy people here that can confirm this 3D model is wrong? And maybe explain how NASA of all organisations keeps showing it on their site? Or is there really a gigantic canyon running as a band over mercury, like someone tried to separate two halves, which somehow shows up in no other pictures I can find? #Astronomy #Mercury #NASA
This NASA site botched texture mapping Mercury pretty badly, and I was so so confused for a very brief amount of time. "Surely," I thought for a second or two, "someone would have noticed and written about this several hundred mile wide saggital canyon that completely encircles the planet. But what if.... aliens?"
@cjrando It's not wrong, but it IS misleading. If you check the model on the website, and zoom in, you'll notice that the edges of the "canyon" are not smooth, but stepped.
This is because the image is a composite taken from multiple photographs taken at different times of the local day by an orbiting spacecraft passing overhead. In some of the images, due to the different times of day when different regions were imaged, there are no shadows and so craters and other features look flat and smooth. In others, the shadows are long and pronounced, making the features look much taller, and more sharply defined.
In other words, there is no canyon. It's an imaging artifact. NASA would have kept it as is in order to be as true to the actual captured image data as possible. They often commission artists to paint objects when they want to give an impression of what something looks like, but that was probably not the goal here.
Full disclosure though: I wasn't involved with creating that image and didn't speak to anybody who was. My answer was an educated guess. I'm pretty confident about it being a mosaic (the stepped edges are a dead giveaway), which is why I spoke to definitively, but I might be wrong on the details of WHY the individual squares look different.
Allen Very Serious Versfeld
in reply to Gidi Kroon • • •@cjrando It's not wrong, but it IS misleading. If you check the model on the website, and zoom in, you'll notice that the edges of the "canyon" are not smooth, but stepped.
This is because the image is a composite taken from multiple photographs taken at different times of the local day by an orbiting spacecraft passing overhead. In some of the images, due to the different times of day when different regions were imaged, there are no shadows and so craters and other features look flat and smooth. In others, the shadows are long and pronounced, making the features look much taller, and more sharply defined.
In other words, there is no canyon. It's an imaging artifact. NASA would have kept it as is in order to be as true to the actual captured image data as possible. They often commission artists to paint objects when they want to give an impression of what something looks like, but that was probably not the goal here.
Gidi Kroon likes this.
Gidi Kroon
in reply to Allen Very Serious Versfeld • •Allen Very Serious Versfeld
in reply to Gidi Kroon • • •You're welcome!
Full disclosure though: I wasn't involved with creating that image and didn't speak to anybody who was. My answer was an educated guess. I'm pretty confident about it being a mosaic (the stepped edges are a dead giveaway), which is why I spoke to definitively, but I might be wrong on the details of WHY the individual squares look different.
Gidi Kroon likes this.