SAN FRANCISCO — The latest campaign by the crowdsource startup Uwingu to sell the naming rights for 500,000 martian craters has drawn the ire of the International Astronomical Union (IAU), the Paris-based organization responsible for determining official names for celestial bodies.

“Not a single Mars crater named as a result of the recently launched Uwingu campaign will be sanctioned by the IAU,” Thierry Montmerle, IAU general secretary, said in a Feb. 27 email. “This should be emphasized very clearly.”

Uwingu announced plans Feb. 26 to invite the public to select names for previously unnamed geographic features on Mars, including craters measuring more than 350 kilometers across. With prices starting at $5, Uwingu hopes to raise more than $10 million for space research and education grants. 

If the project succeeds, it would produce the world’s largest private space grant initiative, said Alan Stern, Uwingu founder, planetary scientist and former associate administrator for NASA’s Science Mission Directorate. 

The IAU objected to a similar Uwingu campaign announced in November 2012 that charged people $4.99 to suggest exoplanet names and 99 cents to vote for their favorite. In August 2013, IAU issued a statement saying that while it has no monopoly on determining celestial object names, it does have extensive experience dating back to its formation in 1919 and asks organizations seeking public involvement in naming campaigns to work with the IAU and to refrain from charging money.  

Mark Sykes, Uwingu co-founder and Planetary Sciences Institute chief executive, anticipated the IAU’s rebuke but said the international organization could not solicit public names for 500,000 geographic features. To complete a task of that magnitude “requires a continuous investment in resources,” Sykes said. “When coupled with the goal of providing a new source of support for research and education, generating those resources by charging for its services is simply practical.”

Uwingu’s Mars map recognizes 15,000 geographic features that already possess names and invites the public to select names for 500,000 additional features, all of which it plans to name by 2015, the 50th anniversary of NASA’s Mariner 4 mission to Mars.