The European Space Agency’s Schiaparelli spacecraft was scheduled to land on Mars on October 19.
No radio transmission was received that should have allowed scientists to track the probe on the surface.
Controllers hope that satellites in orbit around Mars will have detected it and will soon be able to confirm that the probe has fallen safely.
Landing on Mars is always a scary prospect.
This is a high-speed approach that must be done accurately, or the spacecraft risks crashing into the ground.
Schiaparelli had a heat shield, a parachute, and rocket launchers to try to get to the surface intact.
The ESA will not be in a hurry to judge whether this mission has been successful or unsuccessful.
I will wait for the reports of the satellites. Both European and American orbiters were tasked with tracking the event.
If Schiaparelli is later confirmed to be down and safe, he will spend the next few days measuring the Martian environment and current weather conditions – at least until his batteries run out.