Last June, astronomers urged sky watchers to observe the transit of Venus. It was a once in a lifetime opportunity, they said. The black disk of the second planet wouldn't crawl across the face of the sun again for more than 100 years. In fact, it's happening again this week--not on Earth, but Saturn. Read more
Title: Venus transit, aureole and solar diameter Authors: Wenbin Xie, Costantino Sigismondi, Xiaofan Wang, Paolo Tanga
The possibility to measure the solar diameter using the transits of Mercury has been exploited to investigate the past three centuries of its evolution and to calibrate these measurements made with satellites. This measurement basically consists to compare the ephemerides of the internal contact timings with the observed timings. The transits of Venus of 2004 and 2012 gave the possibility to apply this method, involving a planet with atmosphere, with the refraction of solar light through it creating a luminous arc all around the disk of the planet. The observations of the 2012 transit made to measure the solar diameter participate to the project Venus Twilight Experiment to study the aureole appearing around it near the ingress/egress phases.
Title: The Hetu'u Global Network: Measuring the Distance to the Sun Using the June 5th/6th Transit of Venus Authors: Jacqueline K. Faherty, David R. Rodriguez, Scott T. Miller
In the spirit of historic astronomical endeavours, we invited school groups across the globe to collaborate in a solar distance measurement using the rare June 5/6th transit of Venus. In total, we recruited 19 school groups spread over 6 continents and 10 countries to participate in our Hetu'u Global Network. Applying the methods of French astronomer Joseph-Nicolas Delisle, we used individual second and third Venus-Sun contact times to calculate the distance to the Sun. Ten of the sites in our network had amiable weather; 8 of which measured second contact and 5 of which measured third contact leading to consistent solar distance measurements of 152±30 million km and 163±30 million km respectively. The distance to the Sun at the time of the transit was 152.25 million km; therefore, our measurements are also consistent within 1sigma of the known value. The goal of our international school group network was to inspire the next generation of scientists using the excitement and accessibility of a rare astronomical event. In the process, we connected hundreds of participating students representing a diverse, multi-cultural group with differing political, economic, and racial backgrounds.
While astronomers around the world looked to the skies last week to witness Venus move across the face of the Sun, ESAs Venus Express took measurements of the transiting planet from its unique viewpoint. Venus Express is currently the only spacecraft orbiting Venus, but of course could not tell that the 56 June transit was occurring from its location. Read more
Whilst clouds may have obscured the transit of Venus for many in the UK they did help Andrew Steele get this stunning photo from Oxford's Port Meadow. Read more