The images at the NASA Jet Propulsion Laboratory in California reveal a peanut-shaped comet. It is the fifth time that a comet's core has been viewed up close.
The latest mission is not the first for Deep Impact. In 2005, it dazzled the world when it fired a copper probe into another comet, Tempel 1, giving scientists their first look at the interior.
Scientists are interested in comets because they are icy leftovers from the formation of the solar system. Studying them could provide clues to how Earth and the planets were formed 4.5 billion years ago, reports the Daily Mail.
"The mission team and scientists have worked hard for this day," said Tim Larson, EPOXI project manager at NASA's Jet Propulsion Laboratory in California. "It's good to see Hartley 2 up close," he added.
Hartley 2 passed within 11 million miles (17.7 million km) of Earth Oct 20, the closest it has been to our planet since its discovery in 1986.
British-born astronomer Malcolm Hartley, who discovered the comet, said he never imagined a spacecraft would get so close to his namesake find.
"When I saw the comet, it was millions and millions of kilometers away. I'm extremely excited and feel very privileged. After all, I only discovered it," he said.
After the $333 million comet-buster, NASA recycled Deep Impact for a new mission to visit another comet. It was supposed to target comet Boethin in 2008, but it was nowhere to be found. Scientists theorised it may have broken up into small pieces.
Deep Impact was then redirected to Hartley 2. Roughly three-quarters of a mile or 1.20 km wide, Hartley 2 is the smallest comet to be photographed up close.