Nasa photographer John Grant has captured a strange sight above the Marshall Islands in the Pacific.
The odd blue clouds look like a unique aurora hanging in the sky - and at first glance it's easy to think it could be evidence of a UFO, or some other strange phenomenon.
Fortunately for our sense of reality, it's neither of those things.
In fact the picture was taken shortly after the launch of two sounding rockets launched from Roi Namur on 7 May.
The rockets are part of an attempt to study how winds and electrical activity works in the upper atmosphere.
The white-blue cloud was made by the release of trimethyl aluminium, while the red cloud above it was made by lithium vapour.
These chemicals were released intentionally to help study how the winds in the ionosphere - known as neutral winds - work.
Universe Today has more details on the experiment - but some of the other best clouds captured by Nasa's cameras are copied below.
In this photo posted on Twitter by Canadian astronaut Chris Hadfield on Jan. 6, 2013, a Noctilucent Cloud, a rare super high altitude cloud barely visible from Earth, is seen at dawn in the mesosphere from International Space Station. Hadfield is on a five-month visit to the space station and will become the first Canadian to take command of the giant orbiting laboratory in March. (AP Photo/The Canadian Press via NASA,Chris Hadfield)
In this image provided by NASA polar mesospheric clouds in the Northern Hemisphere are featured in this image photographed by an Expedition 31 crew member on the International Space Station June 13, 2012. In both the Northern and Southern Hemisphere, during their respective late spring and early summer seasons, polar mesospheric clouds are at the peak of their visibility. Visible from the ground during twilight, aircraft in flight, and the International Space Station, they typically appear as delicate shining threads against the darkness of spacehence their other name of noctilucent or "night-shining" clouds. Polar mesospheric clouds form between 76-85 kilometers above the Earth's surface, when there is sufficient water vapor at these high altitudes to freeze into ice crystals. The clouds are illuminated by the setting sun while the ground surface below is in darkness, lending them their night-shining properties. In addition to the illuminated tracery of polar mesospheric clouds trending across the center of the image, lower layers of the atmosphere are also illuminated; the lowest layer of the atmosphere, the stratosphere, is indicated by dim orange and red tones. While the exact cause of formation of polar mesospheric clouds is still debateddust from meteors, global warming, and rocket exhaust have all been suggested as contributing factorsrecent research suggests that changes in atmospheric gas composition or temperature has caused the clouds to become brighter over time. (AP Photo/NASA)
This image provided by NASA photographed by an Expedition 28 crew member onboard the International Space Station, provided this image Aug. 30, 2011 shows the moon at center, with the limb of Earth near the bottom transitioning into the orange-colored troposphere, the lowest and most dense portion of the Earth's atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue- colored atmosphere. The silvery-blue noctilucent clouds extend far above the Earth's troposphere. (AP Photo/NASA)
This natural-color satellite image provided by NASA was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite on Saturday June 11, 2011 of the Puyehue-Cordon Caulle eruption in Chile. In the image, the ash plume from the volcano is visible center. Some airline flights to and from New Zealand were canceled Sunday as the ash cloud from the erupting volcano in southern Chile spread. (AP Photo/NASA)
Space Shuttle Discovery Continues On Its Last Mission
IN SPACE - FEBRUARY 26: In this handout image provided by NASA, backdropped by a cloud-covered part of Earth, space shuttle Discovery approaches the International Space Station during STS-133 rendezvous and docking operations February 26, 2011 in Space. Docking occurred at 2:14 p.m. (EST) Discovery, on its 39th and final flight, is carrying the Italian-built Permanent Multipurpose Module (PMM), Express Logistics Carrier 4 (ELC4) and Robonaut 2, the first humanoid robot in space to the International Space Station. (Photo by NASA via Getty Images)
Hurricane Rita Charges Towards Texas Coast
IN SPACE - SEPTEMBER 23: This satellite image from NASA taken on September 23, 2005 shows Hurricane Rita as it started making landfall. Rita was a Category Three Hurricane when it hit the coastline of Texas and Louisiana. (Illustration by NASA via Getty Images)
Hurricane Rita Charges Towards Texas Coast
IN SPACE - UNDATED: In this undated satellite composite from NASA, Hurricane Rita is shown in the Gulf of Mexico west of Florida heading towards the Texas coast. Rita was downgraded to a Category Four Hurricane. (Illustration by NASA via Getty Images)
Saturn's southern polar region exhibits
SPACE, SPACE: Saturn's southern polar region exhibits concentric rings of clouds which encircle a dark spot at the pole as seen in this NASA Cassini spacecraft image released 04 August, 2004. To the north and toward the right, wavy patterns are evident, resulting from the atmosphere moving with different speeds at different latitudes.The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. AFP PHOTO/NASA (Photo credit should read HO/AFP/Getty Images)
IN SPACE - JUNE 5: An image of the tip of the Cone Nebula, which is about half a light-year long as taken by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard NASA's Hubble Space Telescope as it penetrated layers of dust in a star-forming cloud to uncover a dense, craggy edifice of dust and gas, released June 5, 2002. The entire nebula is 7 light-years long. The Cone resides in a turbulent star-forming region, located 2,500 light-years away in the constellation Monoceros. (Photo by NASA/Getty Images)
Hubble''s Panoramic Portrait of a Vast Star-Forming Region
392439 05: An image from NASA''s Hubble Space Telescope of a vast, sculpted landscape of gas and dust where thousands of stars are being born, July 26, 2001. The star-forming region, called the 30 Doradus Nebula, has the largest cluster of massive stars within the closest 25 galaxies. (Photo Courtesy of NASA/Getty Images)