Today, Comet ISON is approximately 2.75 AU from the sun. There are 125 days until Comet ISON reaches perihelion.
Over the past 5 days, between July 21st and July 26th, Comet ISON traveled a distance of approximately 0.073 AU.
That’s an average speed of roughly 1.36 million miles per day, or 2.18 million kilometers per day.
On July 20th, the time projected (tp) value calculated by NASA for perihelion (closest to the sun) was 2013-Nov-28.77831993.
That’s the same as November 28, 2013 at 18:40:46 UTC.
Here are some news snippets from the past week.
“Images captured June 13 with Spitzer’s Infrared Array Camera indicate carbon dioxide is slowly and steadily “fizzing” away from the so-called “soda-pop comet,” along with dust, in a tail about 186,400 miles (300,000 kilometers) long.
“We estimate ISON is emitting about 2.2 million pounds (1 million kilograms) of what is most likely carbon dioxide gas and about 120 million pounds (54.4 million kilograms) of dust every day,” said Carey Lisse, leader of NASA’s Comet ISON Observation Campaign and a senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Previous observations made by NASA’s Hubble Space Telescope and the Swift Gamma-Ray Burst Mission and Deep Impact spacecraft gave us only upper limits for any gas emission from ISON. Thanks to Spitzer, we now know for sure the comet’s distant activity has been powered by gas.”
— NASA 07/23/2013
“Newly released images from NASA’s Spitzer Space Telescope show tons of what appears to be carbon dioxide spritzing away from Comet ISON, the dirty snowball that skywatchers hope will become the comet of the century.
Spitzer’s infrared imagery indicates that 2.2 million pounds (1 million kilograms) of CO2 gas is fizzing away from the “soda-pop comet” every day, along with 120 million pounds (54.4 million kilograms) of dust, said Carey Lisse, a scientist from Johns Hopkins University’s Applied Physics Laboratory who heads up NASA’s Comet ISON Observation Campaign.”
— NBC News 07/23/2013