The Hubble Space Telescope has captured the closest image taken so far of a recent visitor to our part of the solar system, comet NEOWISE. The image, captured on August 8, shows the comet as it zipped past our planet at 37 miles per second, or over 133,000 mph.
Comet NEOWISE was visible in the skies last month, even with the naked eye. It was notable for being the brightest comet in over 20 years, since the Hale-Bopp comet passed by in 1997.
It was named for the NASA mission which first spotted it, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), and became a popular target among amateur astronomers across the world. But if you missed seeing it while it was passing by this time, too bad — astronomers estimate it won’t be back in our region of the solar system for another 7,000 years.
Bright comets like NEOWISE are difficult to photograph as they tend to fall apart due to the immense heat generated as they approach the sun. NEOWISE, however, maintained its solid core of ice so Hubble was able to capture it. The core itself is too small to be photographed, at less than 3 miles across, but the telescope could see the cloud of dust and gas around this core which is more than 11,000 miles across.
The photograph isn’t just for fun, though. It may also teach us more about how comets react to their environments. “The Hubble photos may also help reveal the color of the comet’s dust and how that color changes as the comet moves away from the sun,” the Hubble scientists wrote in a statement. “This, in turn, may explain how solar heat affects the contents and structure of that dust and the comet’s coma. The ultimate goal here would be to determine the original properties of the dust. Researchers who used Hubble to observe the comet are currently delving further into the data to see what they’re able to find.”