Controversial moon dust from Apollo 11 mission is about to be auctioned. Experts believe that the samples collected from the lunar surface might cost about $4 million.

The white bag set to be auctioned in July is believed to contain dust from the moon. It will be auctioned at Sotheby's and may cost up to $4 million.

The price tag is due to the precious materials collected from the moon, which no man had the opportunity to reach in the recent years. The bag was used by Neil Armstrong to carry rocks he collected from the lunar surface for the Apollo mission in 1969.

It was first auctioned to Nancy Lee Carlson who paid $995 for the bag in 2015, according to a report. The same person is expected to get a better return of investment if the bag will be sold at the expected price.

However, before the bag became as public as it is today, Carlson needed to fight for its custody since according to NASA, the moon dust bag was auctioned by mistake the first time around. Reports say it was stolen and passed on from one person to another only to show up in an auction where Carlson found and bought for $995.

Carlson brought the bag to NASA for authentication and the agency filed for the return of the bag to their custody. The judge, however, favored Carlson by saying that the moon dust bag is now rightfully hers.

Now Carlson can legally auction it again. Buyers and collectors can bid for the moon dust bag in July -- coincidentally, during the 48th anniversary of the first Apollo moon landing.

By right, only NASA can own samples from the moon including the tiniest speck of dust. But due to the circumstance surrounding the said box, it is now available to the public. This makes Neil Armstrong's moon dust bag a rare commodity; thus, the surge in its price tag.