Landslides don't just happen on Earth but in deep, dark outer space too.

The Rosetta spacecraft photographed the results of the collapse of about 2,000 tonnes of rubble in July 2015 on Comet 67P/Churyumov-Gerasimenko.

Almost all of the rubble settled at the foot of the cliff.

The rest was ejected in a burst of dust, according to the European Space Agency.

It is the first evidence of landslides on comets and scientists have reported the event in the latest edition of Nature Astronomy.


Image: The fracture can be seen on the Aswan cliff plateau. Pic: ESA

In September 2014, photos were taken of the comet which showed a 70 metre-long, one metre-wide fracture on the cliff edge which was later named Aswan.

Over the following year, the comet drew closer to the Sun and, every now and then, there would be high-speed releases of dust and gas, such as the one captured by Rosetta's camera on 10 July, 2015.

Image: The Aswan cliff on Comet 67P after the landslide in 2015. Pic: ESA

After the landslide, there was an edge where the fracture had been and it was six times brighter than the comet's usual surface, leading scientists to conclude the new surface was the icy interior of the comet.

The effect faded over the following months, however.

Study leader Maurizio Pajola said: "The last time we saw the fracture intact was on 4 July, and in the absence of any other outburst events recorded in the following 10-day period, this is the most compelling evidence that we have that the observed outburst was directly linked to the collapse of the cliff."

Image: An artist's impression of the Rosetta spacecraft approaching comet 67P

The European Space Agency's Rosetta spacecraft was launched in 2004 and travelled more than 3.5 billion miles to reach Comet 67P, which sits around 250 million miles from Earth.

In November 2014, Rosetta released a little robot named Philae onto the comet's surface to explore it.

The billions of comets travelling around the Sun are interesting to scientists because they are believed to be leftover from the birth of the planetary system some 4.6 billion years ago.

September: What have we learned from Rosetta?

The mission found organic molecules on 67P, supporting the theory that comets delivered organic materials when they slammed into Earth.

But comets like 67P were unlikely to have been water sources, the mission found.