Saturday could be the most important day of Darren Julien’s professional life.

At a live event in New York, the auctioneer will sell what he calls the Holy Grail of memorabilia – the rhinestone-studded white glove that Michael Jackson wore when he first performed the moonwalk on the “Motown 25” TV special in 1983.

“I may not ever have an opportunity to sell a single item like this again,” said Julien, chief executive of Julien’s Auctions in West Hollywood. “After the auction on Nov. 21 it will be like the day after Christmas, where you start to feel depressed after all the hype.”

Julien, a lifelong Jackson fan, earlier this year agreed to auction off 2,000 items of Jackson’s memorabilia, but the star later canceled the sale, leading to lawsuits. Despite the conflict, Julien said he and Jackson remained on good terms personally.

“This glove has even more of a special meaning to me because I knew Michael Jackson and worked with him,” he said. “I am not a person who is star struck easily but I remember the first time that I spoke with him and he asked my opinion. I got off the phone and immediately thought: ‘One of the most creative geniuses of our time just asked my advice.’ Hearing the softness when he spoke and the politeness in his delivery humanized the megastar to me.”

The glove, which belongs to Walter Orange of the Commodores, has an estimated price range of $40,000 to $60,000, but Julien wouldn’t be surprised if it sold for several hundred thousand dollars.