NASA’s Deep Impact space probe maneuvered within 435 miles of Comet Hartley 2 on Thursday (Nov. 4), completing a five-year, 3-billion-mile pursuit through the solar system.
The 1,140-pound spacecraft, flying an added NASA mission dubbed EPOXI (which stands for two combined extended missions, “Extrasolar Planet Observations and Characterization” and “Deep Impact Extended Investigation”), took a series of dramatic photos of Comet Hartley 2. Hartley 2 was barely visible in the night sky in late October.
Comet Hartley 2 as seen by the Deep Impact probe.
The encounter took place about 13 million miles from Earth. NASA said the probe was moving at a relative speed of 27,000 miles per hour during the fly-by. Comet Hartley 2 measures about 1 mile wide, and orbits the sun every 6.4 years. It consists of frozen water and carbon dioxide along with silicate dust. It was discovered in 1986.
“The images taken [of Hartley 2] and other science collected should help reveal new insights into the origins of our solar system as scientists pore over them in the months and years to come,” NASA Administrator Charles Bolden said in a statement.
The probe’s cameras focused on what researchers called the comet’s nucleus. "Early observations of the comet show that, for the first time, we may be able to connect activity to individual features on the nucleus," said EPOXI principal investigator Michael A'Hearn of the University of Maryland.
Nervous about possible budget cuts, NASA officials were quick to point out the scientific benefits of the EPOXI mission and a 2005 mission by the Deep Impact probe to the Tempel 1 comet.Click this link to see Deep Impact’s first photos of Comet Hartley.