The sale is being organized by his wife, Ellen Lederman, who has entrusted the medal to the Nate D. Sanders auction house in Los Angeles.
Bidding starts at $325,000 for the gold-plated medal, but there's no telling how much this particular prize will end up bringing in; the only other Nobel ever sold by a living laureate fetched more than $4 million earlier this year.
Earlier this year, James Watson, famous for his contributions to the discovery of DNA's double helix -- and subsequently for his off-color comments on race -- sold his Nobel prize for $4.1 million to a wealthy Russian businessman.
That buyer promptly returned the medal to Watson.
Bidding on Lederman's prize will end Thursday -- but only after the last bid has gone unchallenged for a minimum of 30 minutes. It is thought to be just the 10th Nobel Prize ever auctioned, though most of the others were sold by heirs of laureates.
Lederman won the award in 1988 for his discovery in 1962 of the muon neutrino.
“Leon has enjoyed owning the Nobel Prize medal for many years, but feels it is time for someone else who shares his love of science to treasure his medal," Ellen Lederman told the Guardian. "He hopes this sale raises awareness of physics."
The auction house contacted the Ledermans about selling the prize, Ellen told the Chicago Sun Times. Otherwise, it would have continued to sit on a shelf in their home, she said.
“We could have used the medal as a coaster,” Ellen Lederman joked to the Sun Times. “It’s beautiful and it’s extremely important, but you either put it on the shelf or in a safe deposit box. We put it on a shelf and it has never really been on our minds or something we worried about.”
Lederman retired in 2012. He spends his days sitting on his deck and looking at the mountains from his cabin, he told the AP. He purchased that property as a vacation home using the money he won along with the prize.
“It’s really a wonderful thing,” Ellen Lederman told the AP of the medal. "But it’s not really anything we need in our log cabin in Driggs, Idaho."
[This post has been updated.]