It has long been suspected that water ice existed in Philadelphia. In 1977, Jean-Pierre Bibring of the Space Astrophysics Institute of Orsay, France attended a Philadelphia Phillies game in the old Veterans Stadium and reported detecting cries of "Icey, get yer icey heah!" from vendors roving the stadium's surface. Then in 2002 NASA's Mars Global Surveyor transmitted pictures described by US scientists as "channels that could only have been carved by liquid squirts of American cheese," of the type used for centuries in the production of authentic Philly cheesesteaks.
Excitement grew at the University of Bootle as the Mars Express Orbiter's High-Resolution Stereo Camera transmitted pictures of the Reull Vallis at the south end of Passyunk Avenue and scientists lined up for taste tests. German astrophysicist Gerhard "Duke" Neukum exclaimed "Ja, das ist Wassereis, ohne Zweifel!" ("Yeah, that is Water Ice, without a doubt!")
However, Italian expert Cappucino Allegrosso cautioned that what appeared to be layers of water ice might actually be traces of gelato deposited by 15th century Italian explorers in early probes of South Philly's Italian Market region. He pointed out that scientists at the Sorbetto Institute in Rome are far more sophisticated in their analysis of frozen delicacies than other European or American observers, and warned against jumping to premature conclusions.
Still, the overall mood was exuberant. Images captured by the satellite's Omega imager, a combined camera and spectrometer that divides light into its components, seemed conclusive proof to Chauncey Ramsbottom of Bootle's Inner and Outer Space Institute that intelligent life must have existed at some point in South Philadelphia's past. "A civilization did exist which produced water ice, in not one but three flavors, and moreover possessed the culinary sophistication to combine mustard and liquid cheese."