science
can
there be life on Venus? Venus, milliards of years ago, probably had similar conditions like Earth and there was water. However, over time, the water evaporated into the atmosphere and the greenhouse effect intensified, and the planet became wildly hot and acidic.
I
t revolves around sun a bit closer than Earth, and it has dense atmosphere which consists mainly of carbon dioxide with powerful winds; at an altitude of about 60km, the wind speed is about 400 per hour. The planet doesn’t basically have any magnetic field what makes the solar wind to collide straight to the planet’s thick atmosphere. Venus is overall different from the other planets; the planet itself revolves very slowly. It takes 250 Earth days for Venus to revolve around its axis. Therefore, the day is almost one Earth year long. On top of all that, Venus rotates in the opposite direction from the other planets and its axis is tilted about 177 degrees – the Sun rises there from the west and sets to east. The temperature can go up to 500°C, lead melts on the surface and the clouds rain acid. But there is a cloud layer, about 50 kilometers altitude, where the temperature is around 30°C. Even there the conditions are very acidic; there could be acid-resistant microorganisms, adapted to such conditions, which is not a surprise. Even Earth’s atmosphere and clouds have microorganisms. But how there could be life? For sure we know, that there couldn’t been any kind of water based life, similar to what we have on Earth. Life, at its simplest, is an object made up of one or more cells capable of growing, multiplying, and evolving. It has a metabolism and is born and dies. The clouds covering Venus contain a compound – phosphine - and scientists say that its existence can only be explained by a simple life. Phosphine is either naturally from
16 - VOICES
acidic microbes in low-oxygen conditions, or artificially produced. Scientists are still doubting the reason for phosphine’s appearance, and the only way to find out for sure, is to go on the spot and try to find microbes. Gladly, after the moon Venus is the easiest to reach. The beautiful dance of orbits brings Earth and Venus closer together every 19 months. For comparison, there is a moment occurring in a bit more than every two years when Mars and Earth are close to each other. The trip to Venus, when it’s most close to us, would be 38 million kilometers which makes the travel time to be approximately 7 months. After the scientists published the founding of phosphine, many different parties expressed interest of sending new space probes to Venus. There are already several plans, but the only one in the implementation phase is Russia’s Venera-D. Its estimated sending time was 2026. Many are hoping for this to happen faster after the news of phosphine in Venus. This discovery is the most convincing evidence of life beyond Earth by far. Based on this, we can have more serious considerations about possibilities of life for example in Jupiter’s and Saturn’s cloud layers. Selina Niemi sources: Yle.fi | picture: Wikimedia
