Last night Melburnians were treated to the “Melbhenge” phenomenon. It happens twice a year when the sun sets at a specific position within the Hoddle Grid; it dips below the horizon right in the middle of the CBD office towers on Lonsdale, Bourke and Collins Streets.

Viewers see a “mile-long corridor of concrete silhouetting the setting sun – it frames it perfectly”, says Dr Alan Duffy, an astronomer at Swinburne University.

Melbhenge gets its name from Stonehenge, the prehistoric monument in England that experiences similar moments during the year when the sun sets squarely between the huge rocks.

“They did it for religious reasons, we think,” says Duffy. “We of course have [the Hoddle Grid] for efficient time planning reasons, but that doesn’t mean we can’t enjoy it.”

Melbhenge also happens twice a year at sunrise but, due to Melbourne’s geography, those events are less spectacular, making “sunset the one to go for”.

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Similar events occur in any city in the world with a basic east-west grid structure, although Melbhenge and “Manhattanhenge” in New York are the most notable.

“In New York they have grid structures running for many miles,” Duffy explains. “That’s really, I think, the best one in the world, but I like to think that Melbourne was looking pretty good yesterday.”

He hopes that (as it is in New York) Melbhenge becomes a highlight of the year “where people congregate on various street corners to share this celestial experience”.

If you missed it last night, the next Melbhenge sunset is on November 3. The sunset is best viewed standing as far east as you can, looking west. “So you get as much of the mile long corridor of the Hoddle Grid as possible," Duffy says.

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This makes Spring Street a popular location, but finding the best spot for viewing is difficult; astronomers can easily determine a sunset’s location, what’s harder is finding the optimal viewpoint.

Duffy wants more of us to share Melbhenge experiences online so his team can assemble the photos according to mapped locations and recommend where to watch next time.

And once he’s found the best location? “I’d love to see a pop-up bar on the perfect street corner for us all to enjoy next year”.

For more information follow the #Melbhenge and Dr Alan Duffy on Twitter @astroduff.

Lead photo in this article courtesy of photographer David Brewster.