Unless otherwise noted, all images are courtesy of NASA.

Image courtesy of Prof. Kelin Whipple. Used with permission.

Image courtesy of Prof. Kelin Whipple. Used with permission.

Image courtesy of Prof. Kelin Whipple. Used with permission.

Image courtesy of Prof. Kelin Whipple. Used with permission.

Image courtesy of Prof. Kelin Whipple. Used with permission.

Image courtesy of Prof. Kelin Whipple. Used with permission.