If you’ve looked west after sunset recently it’s quite possible you’ve seen an unbelievably bright ‘thing’ in the sky. That thing is Venus. Sometimes referred to as Earth’s twin, it is a rocky planet of a similar size to Earth, but with strikingly different features including surface temperatures in excess of 460ºC and clouds of sulphuric acid. Whilst Venus orbits the Sun in the same direction as all the other planets in the solar system, it has a retrograde rotation, meaning it spins on its axis in the opposite direction to the other planets.
Venus is the third brightest natural object in the sky after the Sun and the Moon and is easy to see with the unaided eye. Venus follows the path of the Sun, to find it look west after sunset. Turning binoculars or a telescope to Venus will reveal its phase. The phases of Venus were first observed by Galileo and offered decisive evidence for heliocentrism. Thick clouds on Venus leave amateur astronomers unable to see any surface details. However, astrophotographers using ultraviolet sensitive cameras can pickup detail in the cloud-tops and professional astronomers have mapped the surface of Venus using radar and with spacecraft such as the Venus Express.
Venus will reach its maximum brightness on February 17th. As it heads towards solar conjunction in late March (when it’s at its closest to the Sun). As it gets closer to the Sun in the sky it will become much more difficult to observe so make the most of it whilst it’s around. After solar conjunction, Venus will go back to being a dawn object, so those of you who are morning larks will get the enjoy this stunning planet for a while. Those of you who prefer the comfort of a warm cosy bed in the morning won’t see Venus again until early 2018.