While holding out faint hope, ground controllers said it seemed the paddling pool-sized lander's parachute may have been discarded too early, and its fall-breaking thrusters switched off too soon.
The lander, dubbed Schiaparelli, was on a test-run for a future rover that will seek out evidence of life, past or present, on the Red Planet.
But it fell silent seconds before its scheduled touchdown, while its mothership Trace Gas Orbiter (TGO) entered Mars' orbit as planned -- part of a joint European-Russian project.
Further analysis must be done of some 600 megabytes of data the 230 million-euro (USD 251-million) craft sent home before its signal died, to "know whether it survived structurally or not."
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This could take "some time", Accomazzo added.
ESA and NASA Mars orbiters, meanwhile, were keeping their eyes and ears open for any signal from the lander.
If not, this would be Europe's second failed Mars landing in a row, joining a string of unsuccessful attempts by global powers to explore our planetary neighbour's hostile surface.
Schiaparelli had travelled for seven years and 496 million kilometres onboard the TGO to within a million kilometres of Mars on Sunday, when it set off on its own mission to reach the surface.
The pair comprise phase one of the ExoMars mission through which Europe and Russia seek to join the United States in probing the alien Martian surface.
The TGO is meant to sniff atmospheric gases potentially excreted by living organisms, while Schiaparelli's landing was designed to inform technology for a bigger and more expensive rover scheduled for launch in 2020.
While life is unlikely to exist on the barren, radiation-blasted surface, scientists say traces of methane in Mars' atmosphere may indicate something is stirring underground -- possibly single-celled microbes.