China to Mars, India to Venus

November 15, 2019 By Lt. General P.C. Katoch (Retd) Photo(s): By ESA
The Author is Former Director General of Information Systems and A Special Forces Veteran, Indian Army


Venus, Earth and Mars

China’s state-run media recently created a buzz in space exploration by announcing plans for a manned mission to Mars (the Red Planet), with a manned mission to the moon as the first step. In a statement published by China Daily, the China Aerospace and Technology Corporation said: “The next steps in (China’s) manned space programmes will be manned exploration of the moon, stating, “We will set up bases on the moon to conduct scientific operations, expand a habitable place for mankind and gain experience and expertise for deep-space expeditions beyond the moon. The long-term goal is to send humans to Mars. The mission would give Chinese scientists opportunities to look for traces of life on Mars and understand the evolution of life on Earth.”

China wants to beat NASA to Mars and send astronauts to look for alien life. NASA’s ‘Curiosity recently found remnants of a mysterious ‘oasis’ on the surface of Mars, raising hopes that evidence of life may also one day be found on the Red Planet. Roger Wiens, principal investigator of the ChemCam instrument at Los Alamos National Laboratory says, “We’ve learned over the years of Curiosity’s traverse across Gale Crater that Mars’ climate was habitable once, long ago… the climate on Mars was not as stable as we thought it was. There were very wet periods and very dry periods. Currently, Mars is a ‘freezing desert’, but it was once wetter and therefore more hospitable.” China had successfully landed a rover on the moon in January 2019, and announced the mission only after it was completed. China has not announced when it will establish a station on the moon.

Concurrently, ISRO scientist Nigar Shaji recently told a group of scientists during a meeting in Colorado on November 8, that ISRO has sent plans to the government for sending an orbiter to Venus and are hoping they'll get approval to go ahead with the mission. The spacecraft could launch in just a few years and would carry more than a dozen instruments, the major objective being to map the Venusian surface and subsurface. Venus is the second planet from the sun. It has a very hellish environment, which makes Venus a very difficult planet to observe from up close, because spacecraft do not survive long on its surface. Venus and Earth are often called twins because they are similar in size, mass, density, composition and gravity. But Venus is the hottest planet in the solar system. Its dense atmosphere traps heat in a runaway version of the greenhouse effect that warms Earth. Venus temperatures rise to 465 degrees Celsius (870 degrees Fahrenheit) because of which probes landing there have survived only few hours before getting destroyed.

The atmosphere is heavier than that of any other planet, leading to a surface pressure 90 times that of Earth. There is no liquid water on its surface. Roughly two-thirds of the Venusian surface is covered by flat, smooth plains that are marred by thousands of volcanoes, some which are active, ranging from about 0.8 to 240 km, with lava flows carving long, winding canals up to more than 5,000 km long. Six mountainous regions make up about one-third of the Venusian surface. Maxwell mountain range is about 870 km long and about 11.3 km high. Venus takes 243 Earth-days to rotate on its axis, by far the slowest of any of the major planets, and because of this sluggish spin, its metal core cannot generate a magnetic field similar to Earth's. The Venusian year equals about 225 Earth-days. According to NASA average distance of Venus from the sun is 108,208,930 km, which is 0.723 times that of Earth. Magnetic field of Venus is 0.000015 times that of Earth's field. The top layer of Venus' clouds zip around the planet every four Earth-days, propelled by hurricane-force winds traveling at about 360 km/h.

This super-rotation of the planet's atmosphere, some 60 times faster than Venus itself rotates, is one of Venus' biggest mysteries. The winds at the planet's surface are much slower, estimated at just few km/h. The European Space Agency spacecraft ‘Venus Express’ (2005-2014) found evidence of lightning on the planet not associated with water clouds but clouds of sulfuric acid. These electrical discharges can break molecules into fragments that can combine with other fragments in unexpected ways. The US, Soviet Union, European Space Agency and Japanese Aerospace Exploration Agency have combined deployed more than 20 spacecraft to Venus. NASA's Mariner 2 came within 34,760 km of Venus in 1962. Soviet Union's Venera 7 was the first spacecraft to photograph the Venusian surface. The first Venusian orbiter, NASA's Magellan, generated maps of 98 per cent of the planet's surface using radar, showing details of features as small as 100m across. Japan's ‘Akatsuki’ was launched to Venus in 2010, but its main engine died during a pivotal orbit-insertion burn, sending the craft hurling into space. However, Japanese were able to correct the spacecraft's course and in 2015, it went into Venus’s orbit. In 2017, having successfully achieved a modified science orbit around Venus, Akatsuki spotted another huge gravity wave in Venus’s orbit. News in March 2017 was that NASA and the Russian Academy of Sciences' Space Research Institute held discussions for collaborating on the ‘Venera-D’ mission, which would include an orbiter, a lander and perhaps a solar-powered airship. The mission was to be launched sometime in the 2020s. For decades, scientists have suspected that bolts of electricity pulse through the thick atmosphere of Venus, perhaps glinting off the world's acidic clouds but proof has eluded efforts till now. Even a careful experiment conducted by NASA's Cassini mission before its long journey to Saturn resulted in more confusion. Scientist can’t understand how lightning on Venus is generated. Lightning could be related to the origins of life. 10 per cent of US economy could evaporate by 2100 according to a federal report released on November 23, 2019 but Venus has an even hotter climate problem than ours, and scientists say we could learn some valuable lessons from it. ISRO was the first to discover water on the moon. It will be a magnificent achievement if ISRO unravels the mysteries of Venus.