SCIENCE IN THE NEWS DAILY
Transit of Venus: Measuring the Heavens in the 18th Century
from the Guardian (UK)
The 1761 transit of Venus was a watershed moment in the history of astronomy. It was the first time astronomers would have the opportunity to measure accurately the size of the solar system. The distance between the Earth and the Sun had been estimated, with variable degrees of success, since the Greeks, but this was different.
Thanks to a rare celestial alignment, Venus was to pass in front of the Sun, taking about six hours to cross the fiery disc. By recording the times of the start and end of the event from widely separated locations around the globe, trigonometry could be used to calculate the distance to Venus and the Sun. With that, Kepler's laws of planetary motion could be used to calculate the orbits of all the planets out to Saturn, the outermost known planet.
For societies that were still struggling with inadequate maps of their own countries, it was an unimaginable leap forward.
Connect With Us:
VIDEO: How Hair Ice Grows
In 2013, American Scientist featured an article on odd ice formations on plant stems, including these curling ribbons of ice. One of the types of ice discussed in the article was hair ice—long, thin strands of ice that grow under quite specific conditions. The only problem is that a new study shows the theory put forth at the time—that gas pressure pushes the water out—isn’t correct... (click the link above to read more).
To view all multimedia content, click "Latest Multimedia."
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.