The Curiosity rover has been on Mars for four years today.

I’m no Jennifer Borresen, but here’s my sketch of the poor lonely Curiosity rover. (Kat Dow)

In that time, it has traveled almost 14 kilometers (8.5 miles, or about 1/10th of the distance a recreational Pokemon Go player might have walked by now) and given NASA scientists a wealth of information about the Red Planet.

Way better than the 87th duck-face selfie you’ve seen in your Instagram feed this week. (NASA)

The car-sized, six-wheeled robot has sent back a host of pictures, and even taken a selfie. And today, for the fourth consecutive year, it has sung “Happy Birthday” to itself.

Curiosity’s SAM chemistry lab uses sound frequencies to analyze samples. That allowed NASA scientists to transmit a program to the rover so it could “sing” its own birthday song.

Crying yet? Curiosity’s mission is to determine if Mars is habitable. If it turns out the Red Planet can support life, maybe someday the poor rover won’t be so alone. Or perhaps it will find the rovers that landed before it, Spirit and Opportunity, and if and when humans arrive on Mars we’ll find it populated by an adorable robot colony.

In the meantime, NASA has also released an online game to commemorate Curiosity’s fourth year, in which you can drive the little rover around. (I managed to collect one water sample before unceremoniously smashing the poor thing’s front wheel into the rust-colored rock.)

Here’s a video from 2013, when the rover sang to itself for the first time.