A meteorite stolen from an Atherton museum in far north Queensland could be worth more than $50,000 on the black market, an astronomy expert says.

Two men stole the space debris from the Crystal Caves museum in the early hours of Monday morning.

The meteorite is the size of a soccer ball, weighs about 11 kilograms and was previously estimated to be worth more than $16,000.

Dave Reneke from Australiasian Science Magazine said it could fetch much more if thieves broke it up, which he said was likely.

"I'd say taking a piece of rock that size could very easily be broken down into smaller pieces and sold for many hundreds of dollars per piece to a collector," Mr Reneke said.

Jessie and Stuart Foster, who donated the meteorite to the museum, with the display at the museum. ( ABC News: Kirsty Nancarrow )

"I do believe, and I can't prove it, but I do believe that there is sort of a black market for this sort of thing."

Mr Reneke said meteorites were valuable for a lot of reasons, not only because of their mineralogy, but what they represent.

"Now these bits of rock are usually between four-and-a-half to five billion years old," he said.

"They come from a place between Mars and Jupiter and if you ever wanted a pristine piece of a planet like the earth, this is where you go."

The meteorite had only just been donated to the museum two weeks prior by Stuart Foster, who found it at the Wolfe Creek meteorite crater in Western Australia more than 30 years ago.

The owners of the meteorite have appealed for its return.

Crystal Caves manager Ghislaine Gallo said she had her suspicions about who may have taken the space debris.

"We had a person in our shop in Cairns that really, really wanted a meteorite," she said.

"He knew that we could get our hands on one and I said to him, time and time again, I'm not prepared to sell you one, so maybe he decided to get it himself."

The crater was formed by a 50,000-tonne meteorite more than 300,000 years ago, leaving behind the second biggest crater in the world.

The crater, which measures 880 metres across, was only discovered during an aerial survey in 1947.