C 2013

At one point, there were concerns the comet might actually collide with the Red Planet. While it ultimately missed by about 140,000 kilometers, it passed close enough that NASA and ESA had to shield their orbiting spacecraft from high-speed comet dust. The event allowed the Curiosity and Opportunity rovers to look up from the Martian surface and capture images of a comet from another world—a first in human history. 3. C/2013 R1 (Lovejoy): The Reliable Performer

Watching ISON's death provided unprecedented data on how solar radiation affects ancient ice. Conclusion c 2013

While results are promising, limitations include [issue]. Future work should explore [deep learning was just emerging; many 2013 papers still used handcrafted features]. At one point, there were concerns the comet