Washington, June 17 : A new finding by NASA''s EPOXI mission is a comet named Hartley 2 that is in a hyperactive state.

An international team of scientists that includes Lucy McFadden of NASA''s Goddard Space Flight Center in Greenbelt, Md, discovered the comet on November 4, 2010 through the EPOXI mission spacecraft.

"From all the imaging we took during approach, we knew the comet was a little skittish even before flyby," EPOXI Project Manager Tim Larson of NASA''s Jet Propulsion Laboratory in Pasadena, Calif., said.

"It was moving around the sky like a knuckleball and gave my navigators fits, and these new results show this little comet is downright hyperactive," he said.

The EPOXI mission found that the strong activity in water release and carbon dioxide-powered jets did not occur equally in the different regions of the comet.

During the spacecraft''s flyby of the comet, with closest approach of 431 miles (694 kilometres), carbon dioxide-driven jets were seen at the ends of the comet, with most occurring at the small end.

In the middle region or waist of the comet, water was released as vapour with very little carbon dioxide or ice.

The latter findings indicate that material in the waist is likely material that came off the ends of the comet and was redeposited.

"Hartley 2 is a hyperactive little comet, spewing out more water than most other comets its size," Mike A''Hearn, principal investigator of EPOXI from the University of Maryland, College Park, said.

"When warmed by the Sun, dry ice -- frozen carbon dioxide -- deep in the comet''s body turns to gas jetting off the comet and dragging water ice with it," he explained.

Another mission discovery is that on the knobby ends of Hartley 2, particularly the smaller end, the surface terrain is dotted with block-like, shiny objects, some as big as one block long and 16 stories tall. These objects appear to be two to three times more reflective than the surface average.

An added surprise was a pronounced increase in the amount of CN gas in the comet''s coma. For nine days in September, about 10 million times more CN gas was given off than usual.

The findings have been published in this week''s issue of the journal Science. (ANI)