Astronomers using NASA’s Solar Terrestrial Relations Observatory (STEREO) spacecraft have captured a series of images of the comet ISON.
This image taken by STEREO-A spacecraft shows comet ISON, Earth, Mercury and comet 2P/Encke. Image credit: Karl Battams / NASA / STEREO / CIOC.
The sungrazing comet ISON, also known as C/2012 S1, was first spotted 585 million miles away in September 2012.
This is ISON’s very first trip into the inner Solar System. That means it is still made of pristine matter from the earliest days of the Solar System’s formation, its top layers never having been lost by a trip near the Sun.
ISON will reach its closest approach to the Sun on Thanksgiving Day, November 28, 2013.
It will be well placed for astronomers in the northern hemisphere during December 2013.
The latest series of images from the STEREO spacecraft shows ISON moving in from the left side over a two-day period from November 20 to 22, 2013.
The spacecraft is currently located on the other side of the Sun, so it sees a totally different geometry to what we see from Earth.
In addition to Earth and Mercury, comet Encke can also be seen moving through the middle of the view.
The Sun sits outside the field of view of STEREO’s camera, located to the right, off-screen, hinted at by the steady stream of particles, called the solar wind, moving in from the right.
