More than one week on from comet ISON‘s close approach to the sun, astronomers are still working hard to determine what exactly happened to the object.
The comet approached the sun on November 28 after traveling for millions of years from outside our solar system. NASA and ESA researchers used a wide array of instruments to capture the comet’s approach, including NASA’s Solar Dynamics Observatory. For several hours during the comet’s approach astronomers were not able to observe the object due to the sun’s brightness, and many had assumed that the comet had disintegrated due to its proximity to the sun. However, NASA and ESA instruments were able to catch a glimpse of what was left of the comet on its way out of its approach.
Following its approach, astronomers observed a glint that was far less bright than the comet had been in the days previous to the approach. In the days since the object has faded away to almost nothing. Researchers are now trying to work out whether the remainder seen after approach was the ice core of the comet that survived or whether it was simply reduced to debris by that time.
NASA today stated that researchers are continuing to research exactly what happened while the comet was out of view. What can be confirmed already is that the comet shrank “considerably” during its approach and that at this time it is likely only dust.
Astronomers are hoping that the vast amount of data collected on ISON will provide new discoveries for years to come. A video of the comet’s approach and the aftermath was released this week by NASA. The footage comes from the NASA/ESA Solar and Heliospheric Observatory (SOHO):