Who discovered Comet Hartley 2 and when?
Malcolm Hartley discovered Comet Hartley 2 in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, in Australia. The comet was later formally designated 103P/Hartley by the Minor Planet Center.
Questions about 103P/Hartley
Short answers, pulled from the story.
What spacecraft visited Comet Hartley 2 and how close did it get?
NASA's Deep Impact spacecraft, operating as part of the extended EPOXI mission, flew within 700 km of Hartley 2 on the 4th of November 2010 while moving at 44,300 km/h. This made Hartley 2 the fifth comet ever visited by a spacecraft and the smallest comet ever visited.
What is the size and shape of Comet Hartley 2?
Hartley 2 is estimated to be 1.2-1.6 km in diameter, with the EPOXI flyby confirming a length of 2.25 km. Its shape has been described as peanut-shaped, or more colorfully, as a cross between a bowling pin and a pickle.
What does Comet Hartley 2 heavy water ratio tell us about Earth's oceans?
The Herschel Space Observatory detected in 2011 that the ratio of heavy water to regular water in Hartley 2 matches the ratio found in Earth's oceans. Hartley 2 contains half as much heavy water as other comets previously analyzed, making it the first comet with an ocean-matching heavy water ratio.
What role does carbon dioxide play in Comet Hartley 2 activity?
Jets of frozen carbon dioxide, rather than direct water ice sublimation, drive material off Hartley 2's rough ends, dragging hundreds of tons of water ice and dust chunks into space. The 4th of November 2010 flyby marked the first time comet activity powered by carbon dioxide sublimation had been directly observed as a comet approached the Sun.
Will Comet Hartley 2 ever cause a meteor shower on Earth?
Hartley 2 is not yet a known source of meteor showers. However, dust trails from the comet's recent returns move in and out of Earth's orbit, and the 1979 dust trail is expected to intersect Earth's path in both 2062 and 2068.