The distance between the Earth and the Sun, known as the Astronomical Unit (AU), has a fundamental role to Astronomy: it provides a scale distance inside our solar system and supports the measure from the Sun to near stars. Then, in this work we present one of the methods to obtain the AU using the Venus transits in front of the Sun. This is an adaptation to the Halley's method and was applied with the help of the free software of Astronomy Stellarium. We found (1, 4 ± 0, 3) ⋅ 108km, which gives 93, 6% of accordance with the literature. The revision of the method of obtaining the AU using the planet's transit meets either pedagogical and scientific reasons: the work proposed here may be easily reproduced in classrooms from high-school to the college, in courses related to Astronomy. Besides, the Venus transit itself from June 2012 was used to measure the solar radius with an uncertainty of only 15km, which justifies its study. Finally, this work checks the consistence of Stellarium for we have determined via geometrical means the AU inserted into the program.
Keywords:
Astronomical Unity; Astronomy; Venus transit
