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In just over a month, Rosetta engineers will hope to make space history by landing a small robot on the surface of an icy comet for the first time.

The craft has now beamed back a number of measurements to help make that landing a success - and they're so accurate, they can be used by anyone to 3D print their own duck-shaped comet.

Mission scientists had previously only been able to say that the comet was about 2.4 miles (4km) wide, but the latest data provides a more definite shape for 67P. 

Rosetta has beamed back a number of measurements to help make that the landing a success – and they can also be used by anyone to 3D print their own duck-shaped comet. Pictured is the latest shape model of 67P/C-G

And now scientists have revealed that the head, or smaller lobe of the comet, is 1.5 miles by 1.5 miles by 1.2km (2.5km by 2.5km by 2km).

The 'body' has been measured as being 2.5 miles (4.1km) by 1.9 miles (3.2km) by 0.8miles (1.3km) and the rate it rotates is now known to be once every 12.4043 hours.

The images are available as .wrl and .obj files from Esa's website, which means anyone with the appropriate software and a 3D printer will be able to create a physical model of the comet.

As Rosetta edges closer to the comet, it is sending back increasingly clearer images of its target. It plans to send the Philae lander on the comet's surface on November 12.

Scientists have revealed that the head, or smaller lobe of the comet, is 1.5 miles by 1.5 miles (2.5km by 2.5km by 2km). The 'body' has been measured as being 2.5 miles (4.1km) by 1.9 miles (3.2km) by 0.8miles (1.3km)

Last week, Rosetta engineers spotted mysterious jets of water vapour spurting from the surface of comet 67P/Churyumov-Gerasimenko.

It's known that as the comet approaches the sun its surface will melt, expelling vapour into space, but why the vapour is appearing as jets from only certain points on the surface is unclear.

In a blog post, Esa Space Science Editor Dr Emily Baldwin explained that the four images are a montage taken on 26 September from a distance of 16.3 miles (26.3km) from the comet's centre.

'What we're seeing is the product of ices sublimating and gases escaping from inside the comet, carrying streams of dust out into space,' she wrote.

'Zooming in close to the surface and to the source of this activity, and it is apparent that it is originating from several discrete locations.'

In the image, the jets can be seen travelling into space from the comet.

This amazing new image reveals more jets of water vapour on Comet 67P (shown). The latest mosaic of the jets was created by stitching together images from Rosetta. Emily Lakdawalla of The Planetary Society first spotted the jets last month but their origin and formation remains a mystery

They are centered on one location, the middle of the comet, with no other part of the comet seeming to have such jets.

This may suggest that, as the comet has orbited the sun many times before, much of its ice may have already melted.

This would mean that only small pockets of ice melt and produce vapour in this way as it approaches - which could explain the formation of specific jets.

As the comet approaches the sun it will become more active, and scientists will be hoping for more opportunities to view features like these.

Dr Baldwin continued: 'As the comet gets progressively closer to the sun along its orbit, the surface will become warmer, and the level of activity will increase, producing a vast coma around the nucleus, along with a tail.

'It's perhaps hard to believe looking at images like this at less than 30km [18.6 miles] distance from the surface, but recent gound-based images have revealed that 67P/C-G's coma already extends at least 19,000km [11,800 miles] from the nucleus!'

In other Rosetta news, digital imaging professor Mattias Malmer created a 3D model of the comet's surface, reports Dr Emily Lakdawalla from The Planetary Society.

His montage, using data from Rosetta's Navcam, shows the comet as seen on 24 September 2014.

He explained that the views were made by projecting images of the comet over a digital model.

This 3D model of the comet's surface was created by digital imaging professor Mattias Malmer. Using data from Rosetta's Navcam, it shows the comet as seen on 24 September

As soon as Rosetta entered orbit around comet 67P/Churyumov-Gerasimenko in August, engineers rushed to find a landing site for its Philae lander - which they have now done.

This is because, as the comet nears the sun, it will become more active, with more potentially hazardous vapour and debris released.

And that activity was first revealed in images last month showing how the comet is indeed giving off water vapour as jets.

As the comet (seen in this 'selfie' with Rosetta) approaches the sun it will become more active. Ice remaining on the surface will melt, surrounding the comet in gas. For this reason, engineers want to perform the planned landing of the Philae lander on the comet as soon as possible before too much vapour is present

In November the Rosetta probe will launch its Philae robot from a distance of about 6.2 miles (10km) to 67P. If all goes to plan, Philae will then make a gentle landing on the comet at walking pace. The lander will drill and collect samples from beneath the surface, delivering them to an onboard laboratory for analysis

Earlier this week scientists picked landing site 'J', shown, as the location where the Philae lander will touch down. Site J offers the minimum risk to the lander in comparison to the other candidate sites, and is also scientifically interesting, with signs of activity nearby

Zoom in on the image below to find out where Rosetta is at the moment