85P/Boethin

Boethin ( official name 85P/Boethin ) is a short- period comet, which was targeted by the expanded mission of NASA's Deep Impact spacecraft in conversation.

Discovery

The comet was discovered on January 4, 1975 by the priest and amateur astronomer Leo Boethin in the Philippines at an apparent magnitude of about 12mag. Soon after, showed the orbit determination that there is a short-period comets.

Orbit

The comet moves in an elliptical orbit around the sun, the sun closest point of its orbit ( perihelion ) just outside the orbit of the earth, and the sonnenfernste point ( aphelion ) is located just inside the orbit of Saturn. The eccentricity of the orbit is 0.778, the orbital plane is inclined 5 ° to the ecliptic. The orbital period of the comet is 11.23 years.

After 1975, the comet was observed even at his return in 1986, where he even reached a brightness of up to 8mag. His next recurrence was predicted for the spring of 1997, but here are no observations of the comet before.

Mission goal for Deep Impact

The comet was designated as a target for as EPOXI, expanded mission of NASA's Deep Impact spacecraft in conversation. The probe should reach the comet in late 2008. After it until December 2007 but failed to locate the comet again, the probe headed instead to the comet 103P/Hartley 2. Maybe comet Boethin is broken since its last observation into smaller fragments that could no longer be detected from Earth.