Grades: 5 to 12

Comets are mysterious, distant travelers originating from the depths of our solar system and orbiting the sun in highly elliptical path. Star gazers see comets as specters with luminous tails arching across the night sky for a month or two, and then disappearing from sight. Our ancestors considered comets to be portents of evil. Some comets never come back, with orbital periods of tens of thousands of years. Others return more often, with periodic orbits of less than 200 years long. For this reason, seeing comets like Halley’s Comet, with its seventy-six year orbit, is often a once in a lifetime experience. Comets are scientifically valuable because they may be remnants of the material out of which the planets and moons formed. Comets may even contain clues about early life on Earth.

Sometimes called “dirty snowballs” comets are small, irregularly shaped lumps of rock, dust, and ice. They originate in either the Kuiper Belt, located outside Neptune’s and Pluto’s orbit, or in the Oort Cloud, hundreds of times farther away from Pluto extending halfway to the nearest star. Gravitational disturbances can cause a comet to go hurling toward the Sun. As a comet enters the inner solar system, heat from the Sun vaporizes the ice, forming an enormous cloud of gas and dust around the tiny comet. The closer the comet gets to the Sun, the more gas and dust blow away forming a tail that stretches out millions of kilometers. As the comet travels away from the Sun to the outer reaches of the solar system, the tail shortens and the gas cloud disappears.

Team members working as scientists and mission controllers will complete the mission with this objective in mind. The mission takes place in the "no-to-distant future", the crew on board the newly completed Challenger Space Station is performing the first mission ever to originate from Earth orbit. The goal is to complete the assembly of a probe and launch it to rendezvous with Comet Encke and travel on for a flyby of the asteroid Ceres before returning to Earth.

Thanks to the particle capturing technology developed by NASA's STARDUST project, you will not only be flying by a comet and asteroid, but use an Aerogel collector grid to capture cometary material and interstellar to return to Earth for scientists worldwide to study. However, something mysterious appears on the Navigation screen and must be identified before the mission can proceed. What could it be?