Nasa is looking for private companies to go to the moon and collect dust and rocks on its behalf.
The American space agency says it will pay for the samples, but not for the trips. It hopes they will be collected by 2024.
Experts say the move aims to set a legal precedent for mining on the surface of the moon.
Ultimately, that would allow NASA to one day collect materials useful to colonies there, and, eventually, on Mars.
"But I think the main reason for this initiative is to establish the legal principle that you can take ownership of lunar material," Thomas Cheney, lecturer in space governance at The Open University in the UK, told Euronews.
He explained that are "no specific international guidelines for moon mining" although there are several proposals and discussions taking place at the United Nations-level, he added.
"The United States has been pushing this as a position in international law for over five years now, and now is ripe to encourage actual activity rather than simply expressing an opinion," he went on.
Watch more from the interview in the video player above.
Per the official request released by NASA, the contractor will commit to collect samples of between 50g and 500g of lunar regolith ad/or rock materials from the surface of the Moon.
They will also provide imagery to NASA of the collection and the collected material as well as data to identify where on the Moon it was collected.
NASA administrator Jim Bridenstine wrote in a blog post accompanying the request that the agency's Artemis programme — which aims to land the first woman and next man on the Moon by 2024 — is also focused on "taking steps that will establish a safe and sustainable lunar exploration architecture".
"Next-generation lunar science and technology is a main objective for returning to the Moon and preparing for Mars. Over the next decade, the Artemis programme will lay the foundation for a sustained long-term presence on the lunar surface and use the Moon to validate deep space systems and operations before embarking on the much farther voyage to Mars," he added.
Bridenstine clarified that the solicitation is not limited to US companies alone.
Cheney pointed out that for companies wishing to be awarded a NASA contract for moon dust "the economics are challenging to say the least."
Among the companies he said might be interested might be ispace, a Japanase firm, as well as several others that are already "involved in supporting scientific missions such as those undertaken by NASA and the European Space Agency".
"There will be a lot more activity than there has been but we shouldn't be expecting a California-style gold rush," he added.