103P/Hartley

Discovery

Comet 103P/Hartley 2, also recognized as Hartley 2, was discovered on March 15, 1986, by Malcolm Hartley, an Australian astronomer. It acquired its name as per the standard comet naming convention, honoring its discoverer.

Orbit

Hartley 2 follows an elliptical orbit around the Sun, completing its journey roughly every 6.46 years. During its orbital path, the comet travels from a position beyond Jupiter's orbit to an inner point within Earth's orbit when closest to the Sun, known as perihelion.

Physical Characteristics

The nucleus of Comet Hartley 2 is relatively small compared to some other comets, estimated to be around 2.2 kilometers (1.4 miles) in diameter. Cometary nuclei typically consist of a blend of ice, dust, rocky materials, and organic compounds. As Hartley 2 approaches the Sun, the heat causes the ice within it to sublimate, releasing gas and dust that form the comet's distinctive coma (the cloud surrounding the nucleus) and tails.

Satellite

One of the most significant events involving Comet Hartley 2 was its encounter with NASA's Deep Impact spacecraft. On November 4, 2010, the spacecraft executed a flyby, passing at about 700 kilometers (435 miles) from the comet's nucleus. This close encounter facilitated detailed observations, enabling the collection of scientific data, including high-resolution images and compositional analysis.

Surface

The observations from the Deep Impact mission yielded critical insights into the comet's nucleus and activity. Notably, scientists observed jets of gas and dust emanating from distinct areas on Hartley 2's surface, providing valuable information about the processes occurring on the comet's surface.

Observations

Following the Deep Impact mission, ongoing observations of Comet Hartley 2 were conducted from Earth during its subsequent returns to the inner solar system. These observations aimed to monitor any changes in its activity and characteristics over time, contributing further to our understanding of cometary behavior and evolution.