Comet ISON is considered dead, but in the latest update a forecaster says that meteor activity from when it was still alive could reach the Earth on January 15.
While the comet was traveling toward the sun, where it likely ultimately met its demise, the comet passed around two million miles from the Earth’s orbit. The Earth arrives at this point on January 15, according to Robert Lundsford of the American Meteor Society.
“Comet ISON was producing a large amount of dust prior to its disintegration,” he wrote in a blog post. “Some feel that despite the distance that some of this dust may still reach the Earth.”
This activity could be in the form of meteors or just clouds.
“The individual dust particles are calculated to be only a few microns in size, too small to produce meteors bright enough to be visible to the naked eye,” he said. “Yet meteor observers are encouraged to view any possible display of meteor activity despite the full moon.”
He added: “While the probability of meteor activity is remote, it is not 100 percent out of the question.”
The area the meteor activity would appear in the sky would lie in the constellation of Leo the lion, which rises during the early evening hours.
Veteran meteor researcher Paul Wiegert of the University of Western Ontario, using computer models of the trajectory of the dust ejected from the comet, said that a meteor shower could come for several days around January 12.
“For several days around January 12, 2014, Earth will pass through a stream of fine-grained debris from Comet ISON,” Wiegert told Dr. Tony Phillips of NASA last year. “The resulting shower could have some interesting properties.”
The debris stream will be hitting at a speed of 56 kilometers per second, or 125,000 miles per hour, but Wiegert projects that they'll be so small that Earth’s upper atmosphere will slow them to a stop.
“Instead of burning up in a flash of light, they will drift gently down to the Earth below,” he said.
The dust could take years to settle out of the high atmosphere, and during that process produce noctilucent clouds, which are icy clouds that glow electric-blue as they float above Earth’s poles.
“This is still speculative, but Comet ISON could provide the seeds for a noctilucent display,” wrote Phillips. “Electric-blue ripples over Earth’s polar regions might be the only visible sign that a shower is underway.”
The dust particles are projected to not be a problem for the International Space Station, though astronauts on board are being told to be careful and keep an eye out for possible anomalies.
“Sky watchers should probably be alert, too,” wrote Phillips. “The odds of seeing anything are low, but Comet ISON could prove full of surprises.”
