In this entertaining follow-up to Moon's First Friends (2019), which portrays similarly anthropomorphized cartoon planets, lonesome Mars wishes for a playtime pal, particularly a pet. But as Dad, the Sun, points out, the family already has Pluto d besides, Mars has seven siblings to play with. But nobody is interested other Jupiter is "busy juggling his many moons," and sister Earth is exhausted ("Just as I put half the humans to bed, the other half wake up"). But then Opportunity and Spirit arrive. Earth has sent the rovers as a gift, and soon the spacecraft "pets" are crisscrossing a delighted Mars' surface, exploring craters and gathering rocks. Later, as he cuddles them and falls asleep, Mars hopes for others. Bright, cheerful art echoes the lively text, depicting the rovers' mission somewhat fancifully from Mars' perspective. Although the riffs on planetary traits may resonate less with kids unfamiliar with them, the appended material, seemingly geared more toward older readers, provides information on the solar system, planet characteristics, and NASA's ongoing rover program, including the expeditions highlighted here.

Two unexpected pets, Spirit and Opportunity, perk up the bored, lonely fourth planet.In the spirit of their Moon's First Friends: How the Moon Met the Astronauts From Apollo 11 (2019), Hill and Paganelli send a lonely Mars to his father, the Sun, for a pet. Denied (Pluto is the whole family's pet), the planet goes from one anthropomorphic solar sibling to another on a seemingly fruitless quest for companionship. This culminates in the violent and exciting arrival of two speedy "little spacecrafts" sent from Earth as a family gift. Fondly watching the puppylike rovers trundle about his orange surface collecting rocks, playing in a sandstorm, and snuggling together for the night, Mars both promises to make them a good home and looks forward to the arrival of future "pets." Smiling faces on all the planets, moons, and rovers in view-which are otherwise rendered with reasonable accuracy-give the outing a cozy tone overall. Better yet, though the rovers' missions get barely a nod in the main narrative, a substantial epilogue fills in the blanks with basic facts about the solar system in general and Mars in particular, plus profiles of NASA and the entire company of Mars rovers from 1997's Sojourner to 2012's still-active Curiosity (with a note about an unnamed, upcoming "new pet").A warm invitation to visitors wheeled or in boots: "Come on over, rovers!" (Informational picture book. 6-9)