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Venus, seen as the small black speck near the sun's bottom edge, makes its way across the star. Natasha Ivanova captured this image with her telescope in Moscow, Russia.
How is Venus different from Earth? For starters, Venus has no oceans and is hot enough to melt lead.
For several hours Tuesday morning, two of the sky's most brilliant objects appeared to meet as Venus, as viewed from Earth, passed in front of the sun. In the so-called "transit of Venus," the black silhouette of the planet was seen moving from left to right across the lower portion of the sun. Venus last passed between the Earth and sun in 1882.
Observers in Europe, Asia and the Middle East were able to witness the entire six-hour journey, which ended around 8 a.m. EDT. In the United States, only those east of the Rockies could catch the transit, with the longest viewing, about two hours, on the East Coast.
The transit of Venus is a rare astronomical event — and one of historic importance. Astronomers first figured out how to measure the distance of the Earth from the sun by timing Venus as it crossed the face of the sun. And the push to make measurements of the transit all over the world led to the European settlement of distant lands, including Australia.