EUROPA / DOCUMENTARY / THE LAST TRANSMISSION
Scientists Found Something Under Europa's Ice and Can't Explain It
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Video published Runtime: 9 min 55 sec
Watch the Europa ghost-signal documentary, then follow its radar clues into the ice-shell evidence and Europa Clipper’s next tests.
The radar echo has a leading scientific explanation: multiple scattering in the ice. The open questions concern the shell’s detailed structure and its relationship to the ocean below.
ORIGINAL VIEWING GUIDE
Watch for three different questions.
Where did the signal begin?
The radio waves were transmitted from Earth. “Ghost signal” refers to a returning radar echo, not an unknown message from beneath the ocean.
What makes it bright?
Scattering within the ice can reinforce the return. The strength and polarization help test that explanation.
What remains hidden?
A shallow scattering signature does not establish a path through the whole shell, an active seafloor or a detection of life.
AFTER THE FILM / RESEARCH COMPANION
Follow the signal to its evidence.
The returning echo
Read the original Earth-based radar study and distinguish a measured return from its ice model.
Examine the radar Evidence FileThe hidden ocean
Follow Galileo’s magnetic clue, a separate argument for a conducting layer beneath the ice.
Compare the ocean evidenceThe next instrument
REASON will investigate the shell with longer wavelengths. Local conditions determine how deeply the waves can probe.
Follow the Clipper milestone