What could shape up to be a fabulous comet is scheduled to swing within Mercury’s orbit in early March. At its brightest, Comet Pan-STARRS, named after the telescope through which it was discovered in June 2011, may shine as brightly as the stars in what we know today as the Big Dipper.
Like all comets, Pan-STARRS carries so-called virgin ices from the far reaches of the solar system, where it normally resides in a formation known as the Oort Cloud, NASA said. The ice could either vaporize completely as the comet approaches the sun—in which case Pan-STARRS would fizzle—or erupt in spectacular sparkling fashion.
“Fresh veins of frozen material could open up to spew garish jets of gas and dust into the night sky,” the agency said in a statement.
“Almost anything could happen,” said Karl Battams of the Naval Research Lab. “Prepare to be surprised. A new comet from the Oort Cloud is always an unknown quantity equally capable of spectacular displays or dismal failures.”
The Oort Cloud, named for the Dutch astronomer Jan Oort, is a hypothesized cloud of ice and rock fragments that is believed to be a major source of longperiod comets. These fragments offer a glimpse back in time, composed as they are of “frozen gases and primitive, dusty material drawn from the original solar nebula 4.5 billion years ago,” NASA said.
Pan-STARRS will make its closest approach to Earth on March 5, when it will be about 100 million miles away—only 7 million miles or so farther away from Earth than the sun. On March 10 it will make its closest approach to the sun, which could impart the solar-heating boost needed to light it up so that it can be seen with the unaided eye, though it would be too far away to discern the colorful detail without a telescope.
The best views could be on March 12 and 13, NASA said, in the western sky near the crescent moon. Since the comet will be so close to the sun, it will only be visible just after sunset.
“My guess is that the primary feature visible to the naked eye will be the gaseous coma around the head of the comet,” said Matthew Knight of the Lowell Observatory in the NASA statement. “The comet’s tail will probably require binoculars or a small telescope.”
Throughout history, comets have often been regarded as harbingers of seminal change. Such was the case with the Great Comet of 1811, which the famed Shawnee Chief Tecumseh used as leverage, along with an earthquake, to get the Muscogee (Creek) to join his resistance against the U.S government.
Tecumseh, the story goes, convinced the Muscogee that the comet, which shone for 260 days and whose tail stretched from near the sun out to the orbit of Mars, signaled his coming. Since his name meant “shooting star,” it was hard to ignore his prediction or the earthquake that followed it soon after he left the southeastern United States, where the Creek then lived. The comet and the New Madrid Earthquake in December 1811 got the Muscogee and other tribes to join Tecumseh’s attempt to reestablish Indian sovereignty.
Until recently it was thought that a huge comet had wiped out the Clovis culture, believed by some scholars to have been the precursors to American Indians. But a study released last month has largely discredited that theory.
As spectacular as comet Pan-STARRS could be, it may not hold a celestial candle to another comet coming our way later this year. When it passes by the sun this November, comet ISON might shine as brightly as the full moon.
Below, NASA paints a picture of Pan-STARRS.