Poor little Mars rover Curiosity would be very sad if it had feelings. NASA’s famous robotic vehicle on Sunday (5 August) celebrated its sixth anniversary on the red planet all alone.

On its first anniversary, Curiosity sang 'Happy Birthday' to itself after being programmed to do so. This happened back in 2013. Curiosity hasn't done it again.

The rover shared a picture on Twitter though. "I touched down on #Mars six years ago. Celebrating my 6th landing anniversary with the traditional gift of iron… oxide. (It puts the red in Red Planet.)" (SIC) is what it wrote.

The rover was sent to Mars in 2012 and landed on the Gale Crater. It continues to explore the planet and send data and pictures for the scientists to analyze.

Twitterati had kind words to say to the rover on its birthday. Katastrofee said, "Happy Birthday little robot! We just looked up in the night sky to Mars and thought of you. You do an amazing job, buddy."

 

Curiosity has travelled 12 miles on Mars, discovered signs of water and also found an ancient freshwater lake at the floor of Gale Crater.