From billions of kilometres away, comet ISON recently embarked on a dangerous journey near the sun, but it ventured too close. NASA are currently investigating what is left of the comet, which forms part of the so-called ‘sungrazing’ group of comets.

The comet was discovered more than a year ago by Vitali Nevski and Artyom Novichonok using a telescope as part of the International Scientific Optical Network (ISON). Made up of solidified gases, ice and rocks, the comet reached perihelion, its closest approach to the sun, on November 28 at around 8pm. It passed less than two million kilometres from the solar surface, but unfortunately this seemed to be enough to break it up.

The two images above show comet ISON before and after its close encounter, as photo­graphed by the LASCO cameras on board the SOHO spacecraft in space. The bright comet is seen on the right image as it quickly approaches the sun, but something much fainter exits near the top of the left-hand image.

Initially it was thought that the comet was lost, but ISON surprised observers as parts of it became visible after the perihelion passage. Astronomers think that what remains is basically a cloud of dust as the rest of the comet has vapourised off due to the extreme heat and gravitational forces of the sun.

The Hubble space telescope will have a look at it in the coming days as it moves far away from the sun to safely point its delicate cameras at it.

An animated video of the comet’s trek around the sun may be viewed online at http://vimeo.com/80568171 .

www.facebook.com/groups/maltastro

Alexei Pace is president of the Astronomical Society of Malta.

Astronomical events this month

Date Event
   
Tomorrow First quarter moon at 5.12pm.
Tuesday Venus at greatest brightness (evening sky).
Friday/Saturday Geminid meteor shower maximum (40-50 per hour).
December 17 Full moon at 11.28pm.
December 21 Winter solstice in the northern hemisphere – winter starts.
December 25 Last quarter moon at 3.48pm.
December 26 Comet ISON at closest approach to the earth (64 million kilometres). Mars close to the moon.
December 29 Saturn close to the moon (morning sky at 5am).

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.