Planet Venus is similar to Earth in many ways and is often referred to as Earth’s ‘twin planet’. Yet, it is also very different. This has been an area which has fascinated space scientists for some time now. Since 1962, Venus has been investigated by many spacecraft – from fly-bys, orbiters, descending probes and even two balloons. Yet, the planet, shrouded in a thick global cloud cover made of dilute sulfuric acid droplets, has not given up its mysteries, said Dr. Sanjay S. Limaye, Senior Scientist, Space Science and Engineering Center, University of Wisconsin, USA, who recently delivered a lecture on ‘Venus – So near, Earth like and yet so very different’, at Mumbai’s Nehru Planetarium.
Even though Venus is a small planet, its proximity to Earth makes it the second brightest object in our night sky. Its atmosphere also makes it the hottest plant, even though Mercury is closest to the Sun. Dr. Limaye mentioned that though formed at about the same time as Earth and similar in size and mass, Venus today is much warmer, so even though the planet harboured liquid water on its surface in its ancient past, its evolutionary path has been very different from Earth and that of Mars.
According to him, there are many more questions about Venus compared to Mars that puzzle us. Why does Venus rotate backwards slower than any planet in our solar system? When did its surface start getting warmer? Are there active volcanoes on Venus today? Did life evolve on Venus? What substance or substances cause the contrasts in the cloud cover? Why does the atmosphere super rotate? Akatsuki hopes to reveal the answer to the last one at least.
He ended his talk by affirming that Akatsuki will certainly raise more questions about Venus and also shed some light on the existing questions. Without the ability to make measurements from within the atmosphere, we will need to wait for future missions from the international agencies to answer them.