Visiting Venus

FEATURE NEWS

United States Soviet Union Europe Japan Successful Failed HISTORICAL MISSIONS 1989–94 Magellan 2005–14 Venus Express 2010 Akatsuki (active mission) 1962 Mariner 2 1973 Mariner 10 1978 Pioneer Venus 1,2 Used radar to produce the Orbiter detected evidence for geologically Failed to reach orbit initially, but First successful y-by. Con rmed very First close-up Two missions explored atmosphere, highest-resolution maps of the surface, young lava ows, suggesting eruptions in past was successfully inserted into high surface temperature and pressures. images of Venus. surface and space environment and achieving near-global coverage. Revealed few millions years or less. Measured changes orbit ve years later and collected sent down ve atmospheric probes. that volcanic eruptions resurfaced much of in speed of rapidly moving atmosphere, which meteorological data about the the planet in the past 500 million years. circles planet in about four Earth days. planet’s atmosphere.

1961 Sputnik 7 1965 Venera 3 1967 Venera 4 1970 Venera 7 1975 Venera 9 1984 Vega 1,2 1989 Galileo 1997 Cassini 2004 Messenger First failed probe First spacecraft First craft to First lander to send Lander sent back Twin spacecraft dropped Swung past Venus Passed Venus twice Flew past Venus twice attempt. to crash on successfully drop data back from the rst pictures from balloons that spent more on its trip to Jupiter. to gain speed for its on its way to Mercury. surface. probes that explored surface. Survived Venus’s surface. than 46 hours travelling trip to Saturn. atmosphere. for 23 minutes. more than 11,000 km.

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

THE DECADE OF VENUS PLANETARY FACELIFT Nations are planning a number of missions One major question about Venus is whether it to Venus to answer crucial questions about has plate tectonics — the process that the planet’s atmosphere and surface. describes how a planet’s outer shell is broken VISITING into big pieces that shift around and regularly reshape the surface. On Earth, plate tectonics helps to regulate the planet’s temperature.

Trench VENUS Continental Oceanic plate RESEARCHERS ARE EAGER TO plate ENVISION FIND OUT WHY EARTH’S SISTER EUROPE PLANET TURNED INTO SUCH A The European Space Agency is weighing a proposal for a mission that would y as soon as 2032 and HELLISH PLACE. would map certain locations of the Subduction ORBITER VENERA-D planet’s surface down to 1 metre. Subduction happens when one plate rides up INDIA RUSSIA over another, forcing the lower plate to dive The Indian Space Research Russia’s space agency, Roscosmos, into the interior. Researchers suggest that a BY RICHARD MONASTERSKY Organisation is planning to send its is considering a mission that could curved feature on Venus known as Artemis AND SHANNON HALL rst probe to Venus in 2023 to include an orbiter, a lander and even corona resembles the Aleutian trench, which is DESIGN BY JASIEK KRZYSZTOFIAK study conditions on the planet and a balloon to look for conditions that a site of active subduction on Earth. how it evolved. The agency has might support life high above the solicited proposals from planet’s sizzling surface. Aleutian trench, Earth Artemis corona, Venus From a distance, Venus looks a lot like Earth. international researchers for It’s about the same size and density, and is instruments to y on the orbiter. our closest planetary neighbour. But when people rst started exploring Venus using robotic probes, they found that it was hostile — endishly hot with an oppressively heavy, acidic atmosphere. Not the sort of place to bring the family. Yet the dierences are what LLISSE UNITED STATES intrigue scientists. They want to nd out what VERITAS, DAVINCI UNITED STATES NASA researchers are developing a If plate tectonics is happening on Venus, we made the greenhouse eect on Venus go into Long-Lived In-Situ Solar System Two teams of researchers have might not be able to spot the signs in the best overdrive and turn the planet toxic. Explorer (LLISSE) that could proposed relatively low-cost Venus available images of the planet. The San survive on the surface for weeks or missions to NASA. VERITAS would Andreas fault, for example, would not be visible months to collect data about use high-resolution radar to map in topographic radar data that have been conditions and how they change. the planet’s topography, whereas degraded to the same resolution as the images DAVINCI would drop a probe captured by the Magellan spacecraft. But the through the atmosphere to study fault does appear clearly on topographic radar its composition and snap pictures images taken at a resolution that could be of the ground. If one is selected, it achieved in a future Venus mission. could y in the mid-2020s.

15 km per pixel WATER MYSTERY Heavy ATMOSPHERE VOLCANISM cratering Venus’s atmosphere Evidence suggests that there has Earth, Mars and Venus all had liquid water on swirls around the planet been volcanic activity on Venus in their surfaces after a period of intense Earth at hundreds of the past few million years, and bombardment by meteorites in the early Solar kilometres per hour. researchers are eager to determine System. Whereas Mars lost its water early, Venus Venus Researchers can study whether any continues today. probably kept its supply for a long stretch of its the surface using special San Andreas history before the water boiled away. Researchers Mars frequencies of light that fault want to decipher when that happened and why. 240 m 4 billion 3 2 1 Today make it through the per pixel

Volcanic activity Liquid water years thick atmosphere. DYAR; DARBY MYSTERY: TIMELINE: NASA; WATER SOURCES: NASA/JPL VENUS SURFACE: (ALEUTIAN TRENCH); NCEI/NOAA FACELIFT: PLANETARY SOURCES: NASA/JPL (ARTEMIS CORONA); (SAN ANDREAS FAULT).

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