After a long journey from the outer reaches of the solar system, the Comet Pan-STARRS is expected to whiz by about 100 million miles from Earth, skimming the orbit of Mercury, early next month.
But if it survives, Comet Pan-STARRS might send an amazing stream of gas and dust into the night sky, according to scientists with NASA and other observatories.
"However, it could still be difficult to see," Knight added. "From our point of view on Earth, the comet will be very close to the sun.
The comet comes from the Oort Cloud, a shell of icy bodies thought to surround the outer solar system. Comets from the Oort Cloud are like pristine time capsules from the solar system's early life, packed with virgin icy material that has been untouched by the warmth and light of the sun.
Comet Pan-STARRS was discovered in June 2011 by the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS telescope, in Hawaii, which scans the sky for potentially dangerous asteroids and comets that could pose an impact threat to Earth. The cosmic snowball will make its nearest approach to Earth on March 5, when it will come be about 100 million miles (160 million kilometers) away. On March 10, the comet makes its closest approach to the sun.
But astronomers say the best time to look for it might be at sunset March 12 and 13, when the comet will appear not far from the crescent moon.
"My guess is that the primary feature visible to the naked eye will be the gaseous coma around the head of the comet," Knight said. "The comet's tail will probably require binoculars or a small telescope."