Miranda decided that today was going to be a good day. Today, she was going Outside for the first time. As mission commander, it was her privilege to be the first human to set foot on another planet.

Six months of claustrophobic coasting in zero-G had put something of a strain on her team. Six was too few: she would definitely recommend a larger group for the next mission.

She hung up her favourite “Girl on Mars” skirt (so good to be able to wear one again) in her locker and climbed into the bulky pressure suit. Like everything here, it was much lighter than it looked and the over-large backpack was easier than some packs she’d used on Earth.

Formalities over, history made, she headed south, just for a stroll. The unnaturally close horizons rolled slowly towards her. After about a kilometre, she crested a rise and Echus Chasma exploded into view. 4km high cliffs flanked an 80km-wide valley. She gazed in awestruck silence.

Somewhere, a dog barked.

“Oh, God,” she groaned into her suit com, “not again.”