Venus is unique among the Sun ’s planets in having a day longer than its year – that is it turn so easy it takes longer to spread out on its axis of rotation than it does to revolve the Sun . This foreign behaviour is probably a outcome of its deep atmosphere , a case of the buttocks wag the global dog . strange as this is within the Solar System , it may be quite common elsewhere .
Many of the Solar System ’s Moon , including our own , have a rotation period that pair their orbit , make them to always keep the same face to their planet . The same forces that stimulate this so - call “ tidal locking ” use to planets in close - in orbits . It was once thought Mercury would be tidally locked to the Sun , with one burning blistering side , and another cooled by face up forever outwards towards the genius .
Yet according toProfessor Stephen Kaneof the University of California , Riverside it is Venus that nearly ended up with two such differing side , and only its thick atm prevented such an outcome . Kane present his case inNature Astronomy , along with its implication for new discovered planets .
The Venusian twelvemonth is 225 Earth daytime long , but it take up the planet 243 days to rotate .
Yet not everything move so slowly there . The steer on Venus are so tight much of the atmosphere take less than four days to nail a circuit of the satellite , driven by heat imbalances between daytime and nighttime . They trail at the planet ’s rough surface and slow its already ponderous gyration further , and Kane considers them the reason the two periods do n’t match .
" We recall of the atmosphere as a lean , almost separate level on top of a planet that has minimal interaction with the unanimous planet , " Kane said in astatement . " Venus ' knock-down atmosphere teaches us that it ’s a much more integrated part of the planet that affects absolutely everything , even how tight the planet rotates . "
Venus ’s thick-skulled atmosphere of almost thoroughgoing carbon paper dioxide is more illustrious for absorbing the Sun ’s heat very in effect , making the planet hotter even than Mercury and confuse science fiction writers who imagined a humid but inhabitable climate .
The question Kane affectedness is whether these two effects are related : has the duration of Venus ’s daytime contributed to its utmost middling heat and moveaway from habitableness ? The resolution could have important implications for what we can expect to find on rocky major planet that orbit near the inner bound of stars ’ supposed habitable zone .
With so many planet now being found close to their stars , choices have to be made about which are priorities to study with limited telescope time . Decisions will calculate on mannequin of probable conditions . " Venus is our chance to get these models correct , so we can properly understand the aerofoil surround of planets around other sensation , " Kane said . " We are n’t doing a honest job of look at this right now . We ’re mostly using solid ground - type models to interpret the properties of exoplanets . Venus is waving both arms around saying , ' await over here ! ”
If even this seems rather remote from challenges on Earth , Kane points out understanding Venus ’s ambience better could learn us about our own . This has happened once already ; one of the thing that alerted scientist to the dangers of a runaway nursery impression was seeing just how hot – 500ºC ( 900ºF ) – Venus had become despite much less sun than Mercury .
