From the September 2013 issue

Watch a Comet 103P/Hartley flyby

In November 2010, the EPOXI spacecraft flew by the dusty snowball Hartley 2.
By | Published: September 23, 2013 | Last updated on May 18, 2023
Comet 103P/Hartley captured by the Epoxi mission.
In the November issue, planetary scientist Matthew Knight described what comets are, where they come from, and how researchers know this information, in “The science of comets.” He talked about the nine spacecraft that have visited the dusty snowballs, including the Extrasolar Planet Observation and Deep Impact Extended Investigation (EPOXI) probe. This craft flew 435 miles (700 kilometers) from Comet 103P/Hartley November 4, 2010, and captured images and other data of the cometary nucleus. Below is a video that NASA compiled from the photographs that EPOXI took. For reference, Hartley 2’s peanut-shaped nucleus is just 1.4 miles (2.2km) long.