The Rosetta spacecraft captured this image of Comet 67P on September 20, 2016 when the Rosetta was 8.5 miles from the center of the comet. The European Space Agency craft is scheduled to crash-land into the comet on September 30, ending its 10-year, four-billion-mile journey. Scientists decided to crash-land the probe on the comet because its solar panels won't be able to collect enough energy to power Rosetta as it hurtles away from the Sun along 67P's elliptical orbit. (Photo by ESA/Rosetta/MPS for OSIRIS Team MPS)





Expedition 48 Commander Jeff Williams and Flight Engineer Kate Rubins (pictured) of NASA conducted a six-hour and 48-minute spacewalk on September 1, 2016. The pair successfully retracted a thermal radiator, installed two enhanced high definition cameras on the station's truss and tightened bolts on a joint that enables one of the station's solar arrays to rotate. The spacewalk was the second for Williams and Rubins in just 13 days, the fifth of Williams' career and the second for Rubins. (Photo by NASA)





Two satellites are launched from the International Space Station on September 14, 2016. “Like skydivers soaring towards the earth|, wrote astronaut Kate Rubins when she tweeted the photo. (Photo by Kate Rubins/NASA)





The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)





A handout picture provided by the Indian Space Research Organization (ISRO) shows the fully integrated PSLV-C35 taking off from the launch pad at Sriharikota's Satish Dhawan Space Centre in Andhra Pradesh, India, 26 September 2016. ISRO successfully put into orbit its own weather satellite SCATSAT-1 and seven others, including five foreign ones, according to media reports. (Photo by EPA/Stringer)





The southern tip of Italy is visible in this image taken by the Expedition 49 crew aboard the International Space Station on September 17, 2016. The brightly lit city of Naples can be seen in the bottom section of the image. A Russian Soyuz spacecraft docked at the station is at right. (Photo by NASA)





The International Space Station passes in front of the moon in this multiple exposure from September 23, 2016, captured in Russia's Primorye Territory. (Photo by Yuri Smityuk/TASS via ZUMA Press)





The Soyuz TMA-20M spacecraft is seen as it lands with Expedition 48 crew members, NASA astronaut Jeff Williams, Russian cosmonauts Alexey Ovchinin, and Oleg Skripochka of Roscosmos near the town of Zhezkazgan, Kazakhstan on Wednesday, September 7, 2016. Williams, Ovchinin, and Skripochka are returning after 172 days in space where they served as members of the Expedition 47 and 48 crews onboard the International Space Station. (Photo by Bill Ingalls/AFP Photo/NASA)





The International Space Station (ISS) crew members (L to R) Jeff Williams of the U.S., Alexey Ovchinin and Oleg Skripochka of Russia, are seen inside the Soyuz TMA-20M spacecraft capsule after landing near the town of Zhezkazgan (Dzhezkazgan), Kazakhstan, September 7, 2016. (Photo by Bill Ingalls/AFP Photo/NASA)





Four lasers reach into the night sky at the European Southern Observatory's Very Large Telescope on September 2, 2016 in Paranal, Chile. The lasers are a part of the adaptive optics system on the VLT which allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy. (Photo by F. Kamphues/ESO)





Using Chandra and other X-ray observatories, astronomers have found evidence for what is likely one of the most extreme pulsars, or rotating neutron stars, ever detected. This composite image, released on September 8, 2016 shows RCW 103 and its central source 161348-5055 in three bands of X-rays detected by Chandra with low, medium, and high-energy X-rays colored red, green, and blue respectively. (The X-ray data have been combined with an optical image). The central source RCW 103 has properties of a magnetar, a highly magnetized neutron star, yet spins at the relatively slow rate of once about every six and a half hours. This would make it the slowest spinning neutron star ever detected. (Photo by Chandra X-Ray Observatory Center/NASA)





The International Space Station flies approximately 250 miles over thunderstorms visible during a nighttime pass on September 18, 2016. Lightning can be seen flashing brightly inside the clouds below. (Photo by NASA)





Pluto's largest moon, Charon, appears in a high-resolution, enhanced color view captured by NASA's New Horizons spacecraft in 2015 and released on September 15, 2016. Scientists have learned that reddish material in the north (top) polar region is chemically processed methane that escaped from Pluto's atmosphere onto Charon. (Photo by Reuters/NASA/JHUAPL/SwRI)





This shot from the NASA/ESA Hubble Space Telescope captured on September 5, 2016 shows a maelstrom of glowing gas and dark dust within one of the Milky Way's satellite galaxies, the Large Magellanic Cloud (LMC). This stormy scene shows a stellar nursery known as N159, an HII region over 150 light-years across. N159 contains many hot young stars. These stars are emitting intense ultraviolet light, which causes nearby hydrogen gas to glow, and torrential stellar winds, which are carving out ridges, arcs, and filaments from the surrounding material. At the heart of this cosmic cloud lies the Papillon Nebula, a butterfly-shaped region of nebulosity. This small, dense object is classified as a High-Excitation Blob, and is thought to be tightly linked to the early stages of massive star formation. N159 is located over 160,000 light-years away. (Photo by ESA/Hubble & NASA)





Multi-hued clouds float over the Earth as the the International Space Station orbits some 250 miles overhead on September 18, 2016. (Photo by NASA)





A handout picture dated 08 September 2016, issued by NASA/JPL-Caltech/MSSS on 09 September 2016 showing the rim of Gale Crater visible in the distance, through the dusty haze, in this view of a sloping hillside on Mount Sharp as pictured by NASA's Curiosity Mars rover. NASA says the Martian buttes and mesas rising above the surface are eroded remnants of ancient sandstone that originated when winds deposited sand after lower Mount Sharp had formed. (Photo by EPA/NASA/JPL-Caltech/MSSS)