Comet that could reveal Earth’s beginnings shoots past us before disappearing for 200 years

Comet 67P/Churyumov-Gerasimenko took a decade to reach until the Rosetta spacecraft met it in 2014

A ‘rubber duck’ comet made its closest approach to Earth over the weekend and will now not return to our planet for another 200 years.

Comet 67P/Churyumov-Gerasimenko came 62.8 million kilometres close to our planet – closer than Mars – before leaving our proximity until 2214.

The comet first gained notoriety in 2014, when the Rosetta spacecraft approached over the course of a 10-year chase. At the time, scientists involved called it “the sexiest, most fantastic mission ever”.

The ball of ice received its fowl-related description from the fact that the comet appears as two fused pieces of rock that look like the bath toy – albeit one that is approximately 2.6 miles wide.

Rosetta orbited the comets for nearly three years, taking measurements about the comet’s surface and its immediate surroundings.

It landed a smaller craft, called Philae, on the comet to gather information about its chemical composition but not all went well; Philae bounced twice, finally resting in a less-than-optimal area for scientists due to the failure of two harpoons attached to the lander that would secure it to the comet, Space recalls.

“This ice that’s 4.5 billion years old is as soft as the foam that’s on top of your cappuccino, it’s as soft as sea foam on the beach, it’s softer than the softest snow after a snowstorm,” study author Laurence O’Rourke said.

“You cannot just hit it with an object and expect it to move or disintegrate – it would be like punching a cloud.”

The new location of Philae was under a cliff where solar panels could not gain energy for the sun, depleting its reserves after two days – until it briefly awoke in June 2015 when the comet’s angle towards the sun changed.

However, the amount of data collected from the missions make Comet 67P the best-studied of all comets. It helped scientists discover that these celestial objects have their own aurorae, as well as understanding more about the Earth’s own history.

It is possible that Earth was a ‘dry’ planet with water and organic matter seeded here by passing comets, which would make the composition of water on comets the same as that on Earth.