Wednesday, 6 June 2012

beauty mark or parallax view

Our bit of the morning sun has unfortunately been hidden behind steely grey and rainy skies, so we weren’t able to try to see the shadow of Venus crossing the sun ourselves. The intense interest the event has garnered in hobby astronomers everywhere, however, does make me happy and I think expresses continued regard for the sciences and exploration. People flock and cluster around more common lunar eclipses (Sonnenfinsternisse) and meteor showers and though with more heuristic merit than a school science fair project reduplicated without discovery or method, and studying this rare transit will give planet hunters a better understanding of how to spot alien worlds around distant stars, who might disclose their existence by casting a similar tiny shadow and what the roughness of that shadow says about a planet’s atmosphere, size and composition. Historically too Venus has brought together astronomers from different countries and dispatched them to far-flung places, from Tahiti to the Desolation Islands (the French Kerguelen archipelago) by the Antarctic. For really the first time in modern times, scientists cooperated and collaborated on an international level to observe this phenomenon in the 18th century, needing to do so from several different vantage points, irrespective of national or religious convictions: comparing the incidence, size and angle of Venus from different points on the Earth at the same time let scientists extrapolate (from the known distances along the Earth) the distance between the sun and the Earth. That was a pretty nifty trick.