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Historical The escaping atmosphere Mars missions Mars once had a thick atmosphere and a significant amount of liquid water on Soviet Union/Russia the surface, but much of the United States atmosphere has leaked away over TIANWEN 1 Orbiter Europe billions of years. Hope will assess how China’s pioneering mission to Mars will Other oxygen and hydrogen atoms and ions carry an orbiter, rover and lander — it are escaping into space. MARS would be the first nation to achieve all Mission failure three. Both the rover and orbiter have Flyby Lander radar instruments for spotting water Solar and ice on the surface and Orbiter Rover wind Ions and underground. They will also study the atoms planet’s geology and weather. Rover escape 1960 HOPE Ultraviolet INVASION The UAE mission will travel around radiation Mars Mars in an elliptical orbit ranging from Mariner 4 about 22,000 to 44,000 kilometres. It First flyby Three spacecraft carries two spectrometers and a high-resolution imager to capture Lander Mars 3 information about how the atmosphere First lander to heading to the red changes over the day and throughout send back data the seasons.

planet this year will send 1970 back an unprecedented Mariner 9 stream of information First orbiter Helicopter The robot geologist Search for life about the alien world. Mastcam-Z Perseverance carries 43 tubes to hold rock samples Perseverance has several Viking 1, Viking 2 and SuperCam collected and stored by a series of 3 robots. When instruments that will hunt for imagers the samples are eventually returned to Earth, they evidence of life. One of those is could provide the first definitive evidence of whether SHERLOC, which illuminates rocks By Richard Monastersky life once existed on Mars. with an ultraviolet laser and 1980 Design by Jasiek Krzysztofiak records spectra of the 1 The luminescence and reflectance. It 2.1-metre-long Robotic arm can identify the signal of organic robot arm drills with drill molecules and minerals that Never before will such a diverse array of MEDA a thin sample formed in watery environments. scienti c gear have arrived at a foreign weather of rock. station planet at the same time, and with such SHERLOC broad ambitions. Missions from China, the RIMFAX United States and the United Arab Emirates Carousel Coring bit subsurface 1990 radar (UAE) will include two orbiters, two rovers, Ultraviolet a stationary surface laboratory and even a 2 The arm delivers the laser helicopter. They aim to study everything sample to a carousel, which moves the sample Pathfinder from Mars’s buried water deposits to the to the rover’s underside. Scattering Fluorescence MOXIE Carousel top of its atmosphere, with a particular produces focus on the search for life. oxygen from carbon Sojourner dioxide Rover First rover body 2000 Robotic arm

Spectral 3 A second robotic arm map carries the sample to Mars Express Landing sites diœerent instruments for Sealing, volume European A US rover called Perseverance will land in Jezero Crater, initial measurements, then and vision stations Space Agency’s near a delta formed by an ancient river — a prime location seals the tube. first orbiter for finding signs of past life if it existed. China is considering several landing sites for its Tianwen-1 mission. 2010 Tianwen-1 potential landing sites Previous missions PERSEVERANCE Analysis of Curiosity organic material rover The US rover is a car-sized vehicle and minerals packed with seven instruments. Its main India’s Mars Orbiter Mission Phoenix task is to collect rock samples destined Sample Viking 2 to be carried back to Earth in a future Sample handling mission. It will also study the planet’s Perseverance storage arm Viking 1 weather and geology, hunt for water, produce oxygen from carbon dioxide, Pathfinder record sounds for the first time and test Spirit InSight Opportunity a solar-powered helicopter. PIXL SHERLOC SOURCES: LANDING SITES, COMPILED BY X-ray Ultraviolet E. LAKDAWALLA‘PLANETARY SOCIETY; 2020 spectrometer spectrometer ATMOSPHERE GRAPHIC, ADAPTED FROM ESA‘ 4 A future mission will aim to HTTPS:‘‘GO.NATURE.COM‘2ZDWJKA; HISTORICAL Curiosity retrieve the cached samples MISSIONS, NASA; NASA ROVER, Planned NASA‘JPL˜CALTECH; MARS BASE MAP, US and send them back to Earth. GEOLOGICAL SURVEY. missions

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