The accuracy of Eckert's calculations of the Moon's orbit was so good that in 1965 he was able to correctly show that there was a concentration of mass near the lunar surface.
Ang kawastuhan ng Eckert ng mga kalkulasyon ng Buwan ng orbita ay kaya good na sa 1965 siya ay makapag-tama ipakita na nagkaroon ng konsentrasyon ng masa na malapit sa ibabaw ng buwan.