. ▁He ▁sc raw ls ▁" b aby " ▁and ▁" green ▁che ese " ▁on ▁class ▁works he ets ▁about ▁the ▁solar ▁system . ▁ ▁Scient ific ▁humor ▁and ▁ep ist em ology ▁British ▁television ▁Apol lo ▁ 1 1 ▁coverage ▁had ▁inter l udes ▁entitled ▁" But ▁What ▁If ▁It ' s ▁Made ▁of ▁Che ese ." ▁On ▁ 1 ▁April ▁ 2 0 0 2 , ▁NASA ▁" pro ved " ▁that ▁the ▁Moon ▁was ▁made ▁of ▁green ▁che ese ▁with ▁an ▁exp iration ▁( or ▁" s ell ▁by ") ▁date ▁using ▁doctor ed ▁pictures ▁pur port edly ▁from ▁the ▁Hub ble ▁teles cope . ▁At ▁the ▁Science ▁Writ ers ' ▁conference , ▁theoretical ▁phys ic ist ▁Se an ▁M . ▁Car roll ▁explained ▁why ▁there ▁was ▁no ▁need ▁to ▁" sample ▁the ▁moon ▁to ▁know ▁it ' s ▁not ▁made ▁of ▁che ese ." ▁He ▁said ▁the ▁hypothesis ▁is ▁" abs urd ", ▁failing ▁against ▁our ▁knowledge ▁of ▁the ▁universe ▁and , ▁" This ▁is ▁not ▁a ▁proof , ▁there ▁is ▁no ▁met aph ys ical ▁proof , ▁like ▁you ▁can ▁proof ▁a ▁statement ▁in ▁logic ▁or ▁math ▁that ▁the ▁moon ▁is ▁not ▁made ▁of ▁green ▁che ese . ▁But ▁science ▁never theless ▁passes ▁jud g ments ▁on ▁claims ▁based ▁on ▁how ▁well ▁they ▁fit ▁in ▁with ▁the ▁rest ▁of ▁our ▁theoretical ▁understanding ." ▁Not with standing ▁this ▁un cont ro vert ible ▁argument , ▁the ▁harm onic ▁signature ▁of ▁moon ▁rock the ▁se ism ic ▁velocity ▁at