Hundreds of people headed out to RIT's observatory to witness a global celebration. The last transit of Venus of our lifetime took place this evening.

The transit of Venus ended once the sun set. The whole thing lasted for about six hours. RIT'S observatory opened up its doors during the event, and hundreds lined up to take a peek at something they'll never see again.

"This is a twice in a lifetime event, so the last chance anyone in the lifetime will have is now because the next transit of Venus won't occur for about another 110 years,” said Michael Richmond, RIT Observatory director.

It’s why long lines were formed to watch the spectacle at each telescope on the lawn of RIT's observatory.

"We were talking to our mom about it and even our kids, like if we have kids they won't see it in their lifetime. It's something that you should see it now,” said Sanjana Luther of Fairport.

The transit is the moment when Venus passes between the earth and the sun. It can be seen through these telescopes as a small dot gliding across the surface of the sun.

Richmond says the last time this happened was 2004.

"I tried to see the one that occurred in 2004, which was the only other chance in my entire lifetime and I went to an observatory and got out the telescopes and it was cloudy. This time I may actually be able to see it,” Richmond said.

It's such a rare opportunity, Debra Bellare of Rochester wanted to make sure she and her son witnessed.

"Interested in everything the planets, the sun the stars.” Bellare said. “It just fascinates him so I really wanted him to see it."

It was also a fascination for Gretchen Weis of Brighton.

"I went to the New Zealand in the mid-80s to see Halley's Comet and I do enjoy doing these kinds of events,” she said.

Weis says watching history align is a passion of hers, and as Venus slowly trekked across the sun Tuesday evening, for her, the sighting symbolized much more.

"It's a wonderful opportunity to remind us that we are part of a much, much bigger universe,” she said. “Sometimes, it's a very humbling experience to remind us how small we are in the scheme of a much larger world."

The latter part of the transit can be seen tomorrow morning on the other side of the world. The next time one is estimated to take place is December 2117.