North Korea's testing of its Hwasong-15 long-range ballistic missile on 29 November has renewed concerns regarding the threat the country poses for the US. While most experts have been focusing on what they believe is the dictatorship's most technologically advanced missile, some scholars were looking at the background instead — more specifically the sky on the night of the test launch.

On inspecting images of the launch released by North Korea, a space analyst observed that the photos showed inconsistencies in the positioning of constellations that make up the backdrop of the missile test. Dr Marco Langbroek, Space Situational Awareness consultant at Leiden University in the Netherlands, believes the regime tampered with the images, adding stars in the sky.

"The real fun started when... I started to look at the pictures of the actual launch moment. The fact that some of these show stars in itself is already something, as these images necessitate short exposures, so you do not expect stars. But the real fun came when I looked at the stars visible. There, things clearly were not right!" he added.

Langbroek pointed out that in two images, the exhaust plume and position of the number on the missile were almost identical, yet the star-field had been edited. "One shows Orion, which is south-southeastwest. The other shows Andromeda with the Andromeda galaxy which is northwest. So these two images from the same view point, show dramatically opposite sky areas," the scientist explained in his blog.

He also compared two other photos that seem to have been mirror images of the launch but the constellations were different. "So clearly, the starry sky background was added to the imagery and is not original," he said.

"They looked so crisp, that just didn't seem right to me," Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, wrote in response to Langbroek's posts on Twitter. "Stars just don't look that different a few miles apart, and we have no reason to disbelieve that this launch was from the Pyongsong region north of Pyongyang."

Then why did the North Korean government choose to alter the photos?

According to Langbroek and McDowell, it could have been simply to make the missile photos prettier. "The most likely reason is simply that they did it for aesthetics. An ICBM soaring into the stars makes for good propaganda images. They apparently just didn't care enough to do it correctly," Langbroek wrote.

The Kim Jong-un government has taken to photoshop often in the past – from editing their leader's ears, to using dramatic sunset backdrops and even adding sheep to a countryside.

"Maybe they wanted to play a prank on analysts as well: they know these images will be analysed by the west. Fooling around with clues as to the orientation of images makes it harder to glean information from them on three-dimensional missile shape, and launch site geo-location," the Dutch national added.

"Yeah, I think somewhat just wanted to make it pretty. I doubt there's anything deeper here," McDowell concurred.

North Korea's latest missile reportedly uses two engines and no supplementary thrusters REUTERS/KCNA