A spectacular Comet Ison?
This week could see one of the greatest celestial light-shows ever as Comet Ison passes close to the Sun.
Ison’s movement has been tracked over the past year as it moves towards the inner solar system - and on 28 November it is due to pass through the corona of the Sun itself.
Ison is ~4.6 billion years old, having formed at the origination of the solar system, and has been dormant in the outer reaches of the Sun’s gravitational field for most of that time. But, relatively recently, it was knocked out of the distant 'Oort' cloud and began a journey towards the Sun. That trip is very nearly at an end - and astronomers don’t know if it is one that it will survive.
Speaking on BBC, Dr Matthew Knight, who has studied Ison for a year, described 3 possible scenarios for what could happen on 28 November:
- it may be pulled apart by the gravitational force of the Sun, stretching it beyond breaking point and forcing it to explode as it leaves the corona.
- it may succumb to the heat of the Sun. It is made up of ice and other frozen gases, and could experience heat of up to 2,000ºC and simply fizzle out.
- as it flies through the corona, the gases could be heated up and ignited just enough to produce a tail - burning off in the wake of Ison’s flight, but not enough to destroy it entirely.
If option 3 happens, those in Earth’s northern hemisphere could witness an extraordinary display in the night sky - Ison could appear as a bright object near the horizon, with a tail extending all the way overhead.
If Ison does indeed survive its brush with the Sun, it will be visible from 3 December and throughout most of the month.
Further details from The Independent link below.