NASA has unveiled a new stunning image of a volcanic crater on the surface of Mars that holds a "secret meaning." The American space agency shared the image of a peculiar crater on the red planet through its official Instagram account on Monday, April 11. NASA officials wrote in the caption below the image: "Mars Crater Marks the Spot." They continued: "You are looking at 0 degrees longitude on the surface of Mars, equivalent to the Greenwich Observatory on the red planet."
The Greenwich Observatory on Earth is located on a steep hill in London, marking where the Prime Meridian of our planet passes; this imaginary line divides the globe between the northern and southern hemispheres and determines where east meets west. Furthermore, it is used as a "zero reference line for astronomical observations," according to NASA.
In the image of Mars, there is a large volcanic crater located within a second rocky basin, called the "Airy Crater." Originally, "Airy Crater" defined Mars' zero longitude, but as scientists began capturing more detailed images of the planet's surface, they needed a more precise marker. Consequently, NASA designated a smaller crater, named Airy-0, as the main meridian to avoid altering existing maps.
The American space agency captured the image using the High-Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter. Since the image was released, it has garnered nearly 400,000 likes.
