There are thousands of dark and dim asteroids that lurk in the vast dark spaces between the planets in our solar system. Some of these malicious cosmic goblins may even pose a threat to our planet. NASA will soon begin a hunt for these goblins by launching an infrared telescope called WISE in December.

The Wide-field Infrared Survey Explorer, or WISE, will scan the entire sky at infrared wavelengths, creating the most comprehensive catalog yet of dark and dim objects in the cosmos: vast dust clouds, brown dwarf stars, asteroids -- even large nearby asteroids that could someday be on a collision course with Earth.

The heat we feel from sunlight, a hot kettle on a stove or a warm sidewalk is infrared radiation. Stars emit visible light in part because they're so hot. But cooler objects such as asteroids emit light, too, just at longer, infrared wavelengths that are invisible to the unaided eye. In fact, any object that has a temperature above absolute zero (minus 459.67 Fahrenheit) radiates in the infrared. Even cold objects such as an ice cube emit radiation in the infrared. When an object is not quite hot enough to radiate visible light, it will emit most of its energy in the infrared.

Recent surveys of nearby asteroids based on visible-light telescopes could be slanted toward asteroids with more-reflective surfaces. "If there's a significant population of asteroids nearby that are very dark, they will have been missed by these previous surveys," says Edward Wright, WISE mission scientist.

The full-sky infrared map produced by WISE will reveal even these darker asteroids, mapping the locations and sizes of roughly 200,000 asteroids and giving scientists a clearer idea of how many large and potentially dangerous asteroids are nearby.

WISE will also help answer questions about the formation of stars and the evolution and structure of galaxies, including our own Milky Way galaxy.

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