Six minutes before the comet's closest approach, CONTOUR's Remote Imaging Spectrograph, called CRISP, will start taking pictures through ten different filters. These filters sift through the light of the coma and will allow the imager to see right into the comet's nucleus.

The picture-taking pace will quicken as the craft and its comet barrel toward each other at a frenetic speed.

Fifty seconds before the closest encounter, the images will be sent through a spectrograph, a device that sorts the images into 256 different wavelengths.

The wavelengths emitted from the surface of the comet correlate to different chemicals, therefore CRISP will give scientists a detailed map of the chemical and physical landscape of the nucleus in 4-meter sections. This map will be ten times more precise than Deep Space 1's map of comet Borrelly.

The scientists will be looking for carbon-based molecules -- the basis of all known life on Earth. Joe Veverka, the principal science investigator for the mission, explained that carbon rich molecules in the comet's nucleus probably form a tar-like goo on the surface of the nucleus. As the comet sails through the sky, bits of this goo fly off. The dust analyzer will be there to catch and analyze what kind of molecules they are, and scientists will be able to see if comets carry the molecules that are necessary for life.

Much like the dust analyzer, CONTOUR's Neutral Gas Ion Mass Spectrometer will sort and analyze atoms, but atoms from the coma, not the nucleus. This will help scientists better understand the chemical processes that occur as particles are heated up in the nucleus, vaporized, then thrown out to the coma. But more importantly perhaps, the spectrometer will find out what kind of water the comets carry.

It turns out there are several kinds of water. Of course water is made up of hydrogen and oxygen, but hydrogen can be based on one of two different ions, and there are three different oxygen ions. Ions are variations of an element with different electrical charges. The spectrometer will attempt to determine what kind of water the comets carry.

"We know what flavor of water we have in the oceans," said Joe Veverka, CONTOUR's principal science investigator. "If we have the same chemical signature in a comet, then that will help decide if comets are as important to life on Earth as thought."

The data-gathering will last only a few hours. After the data are sent back to Earth, the craft will once again be put into hibernation until three months before the comet Schwassman-Wachmann 3 encounter in June 2006. If the craft fairs well through the comet's storms, and NASA decides to fund a third fly-by, CONTOUR will visit comet d'Arrest in August 2008.

Gathering data from inside the head of more than one comet will be invaluable in understanding the solar system, scientists say.

"The key thing is that we're collecting hundreds of pictures and full data sets of the gas and dust," said Veverka. "That's the big thing, there will be lots of data to do comparisons with."

Comets are thought to form in different parts of the solar system, explained Veverka. So if they are similar in composition, it would indicate the solar system started out as a homogenous mix of ices, gas and dust. But if they are different, then it could mean the solar system started out in a more diverse fashion.

Other missions will help round out the picture of comets in coming years.

"We need to know about the close environment of comets," said Weaver, the Johns Hopkins astronomer. "We have so little information of cometary nuclei that Deep Space 1 and CONTOUR will help prepare for Deep Impact."