Photo: NASA/JPL/UArizona
Although a reliable source of inexhaustible interesting and revelatory images, the HiRISE camera that is orbiting Mars rarely sends back images of places that may become historically important for a potential human colony there.
The main photo of this piece marks one of those times when HiRISE does do that. It’s a centered image of the so-called Airy-0 crater, located inside a larger crater called simply Airy. Both are named after 1800s British Astronomer Sir George Biddell Airy.
You see, Airy-0 once defined the position of the neighboring planet’s prime meridian, that imaginary and arbitrary line of longitude that helps define coordinates on a planet. That would be the equivalent of Earth’s Greenwich.
In fact, the name for this Martian crater was chosen because Sir George Biddell Airy is the one responsible for building a transit circle telescope at Greenwich, and someone must have seen this as a nice analogy between the prime meridians of the two planets.
We said it “once defined” because, as mentioned, these things are arbitrary, and at one point an organization called the Working Group on Cartographic Coordinates and Rotational Elements (WGCCRE), created by the International Astronomical Union (IAU), decided to move that prime meridian to the place where the Viking 1 lander touched down in 1976.
Until September last year, the Airy-0 had never been photographed from orbit by the HiRISE, but somehow NASA and the University of Arizona seem to have found the determination to do that, and here we are, staring right into the place that will probably earn a footnote in a future book of Martian history.
The image was snapped by the camera from an altitude of 267 km (166 miles), and in its enhanced color state shows an area that is just 1 km (less than a mile) across.
You see, Airy-0 once defined the position of the neighboring planet’s prime meridian, that imaginary and arbitrary line of longitude that helps define coordinates on a planet. That would be the equivalent of Earth’s Greenwich.
In fact, the name for this Martian crater was chosen because Sir George Biddell Airy is the one responsible for building a transit circle telescope at Greenwich, and someone must have seen this as a nice analogy between the prime meridians of the two planets.
We said it “once defined” because, as mentioned, these things are arbitrary, and at one point an organization called the Working Group on Cartographic Coordinates and Rotational Elements (WGCCRE), created by the International Astronomical Union (IAU), decided to move that prime meridian to the place where the Viking 1 lander touched down in 1976.
Until September last year, the Airy-0 had never been photographed from orbit by the HiRISE, but somehow NASA and the University of Arizona seem to have found the determination to do that, and here we are, staring right into the place that will probably earn a footnote in a future book of Martian history.
The image was snapped by the camera from an altitude of 267 km (166 miles), and in its enhanced color state shows an area that is just 1 km (less than a mile) across.
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