David Grinspoon Quote
This comet was much smaller, less than half a mile across, and would miss Mars by about eighty thousand miles. This was still close enough to splatter the atmosphere with hydrogen and dust, producing atmospheric effects that were observable with telescopes and spacecraft. When the close approach occurred, it provided a great opportunity to learn more about the infrequent (on human timescales) but inevitable interactions of planets with comets. For me there was also an unsettling aspect. We hear more about the impact threat from stray near-Earth asteroids, but a comet like this one, plunging at a frightening pace from the dark periphery of the solar system, would be a more formidable threat. In contrast to the many years or even decades of warning we’d likely have for a menacing asteroid, a comet can appear with little notice. This Martian near miss occurred less than two years after McNaught’s discovery. If the wrong comet appeared, we might have only a similar warning interval between detection and Earth impact. The chances of this happening in any year are minuscule, but recent solar system history teaches us that, if we watch long enough, seemingly unlikely objects and events will eventually materialize.
This comet was much smaller, less than half a mile across, and would miss Mars by about eighty thousand miles. This was still close enough to splatter the atmosphere with hydrogen and dust, producing atmospheric effects that were observable with telescopes and spacecraft. When the close approach occurred, it provided a great opportunity to learn more about the infrequent (on human timescales) but inevitable interactions of planets with comets. For me there was also an unsettling aspect. We hear more about the impact threat from stray near-Earth asteroids, but a comet like this one, plunging at a frightening pace from the dark periphery of the solar system, would be a more formidable threat. In contrast to the many years or even decades of warning we’d likely have for a menacing asteroid, a comet can appear with little notice. This Martian near miss occurred less than two years after McNaught’s discovery. If the wrong comet appeared, we might have only a similar warning interval between detection and Earth impact. The chances of this happening in any year are minuscule, but recent solar system history teaches us that, if we watch long enough, seemingly unlikely objects and events will eventually materialize.