The rover was made to operate for just three months, but survived on the planet for 15 years. (The day it launched, the NASDAQ closed at 1,720.71). Opportunity met its untimely end by dust storm eight months ago; flight controllers have been trying to make contact since then. They sent their last set of recovery commands Tuesday night, but were met with silence. (Associated Press)

Talking point: Along with its twin rover, Spirit—which it outlived by several years—Opportunity found critical proof that ancient Mars may have been hospitable to life. Opportunity travelled a record 45 kilometres around the planet, working longer than any other lander in history. After being unable to make contact—and with costs reaching around US$500,000 a month—NASA decided to terminate the project. Now that both Opportunity and Spirit are gone, scientists consider this the end of an era. This won’t be NASA’s last Mars rover, however: it plans to launch Mars 2020 next year, which will test the planet’s soil for signs of past microbial life.