The rover had been on its own since early April, when Mars slipped behind the Sun from Earth's perspective.
Sun can disrupt communications between the two planets in this alignment, which is known as a Mars solar conjunction, so Curiosity's handlers at Mission Control had temporarily stopped sending commands to the one-ton rover.
However, the heavens have shifted, bringing Mars and Earth back in touch and the Curiosity rover back within reach of its masters, SPACE.Com reported.
"Can you hear me now? Conjunction is over. I have a clear view of Earth & am back to work!" NASA officials wrote on behalf of the rover via the Curiosity Twitter feed.
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The rover has already checked off its main mission goal. Before conjunction, Curiosity collected samples from a hole it drilled 6.4 centimetres into a rocky outcrop called John Klein.
The rover's analysis of these samples allowed mission scientists to determine that Mars was indeed habitable billions of years ago.
Curiosity's post-conjunction plan involves drilling another hole nearby, to confirm and extend scientists' understanding of the John Klein area, mission officials have said.
Mars solar conjunctions occur every 26 months, so veterans of NASA's Mars missions are used to dealing with them, the report said.