Siding Spring: How to watch comet's close encounter with Mars live

Comet is due to fly past the Red Planet on Sunday

Siding Spring captured on Nasa's Hubble Space Telescope (Nasa)

Nasa is preparing its Mars orbiters for a ‘duck and cover’ manoeuvre hours before comet Siding Spring is due to hurtle by Mars, in a once-in-a-million years event.

Siding Spring comes from the Oort Cloud - material left over from the formation of the solar system. Astronomers say the comet has travelled many billions of miles to reach Mars.

Siding Spring's nucleus will miss Mars by about 87,000 miles on Sunday, flying by at a speed of about 126,000 miles per hour.

Nasa is now taking steps to protect its Mars Reconnaissance Orbiter, Mars Odyssey and MAVEN orbiters from any comet dust produced by the close fly-by, as well as preserving any opportunities to gather valuable data from the event.

The organisation says Comet Ison in October 2013 gave teams on Mars observatories a good chance to practice looking at an object hurtling past the planet.

Nasa's Mars orbiters lining up behind the Red Planet for their "duck and cover" maneuver (NASA/JPL-Caltech)

The best viewing on Earth, with binoculars or a telescope, will be from the Southern Hemisphere.

For anyone who doesn’t own a pair of binoculars or live in the Southern Hemisphere, the Slooh Community Observatory will broadcast the comet passing Mars here.

The Virtual Telescope Project is also hosting a webcast at 17.45 BST, which you can watch here.

David Humm, of the Johns Hopkins University Applied Physics Laboratory described the event as "unique, unexpected, and lucky for us".