Once there was a time when humans and aliens lived separated from each other. Now, soccer has united them. After beating Neptune, Team Earth travels to Mars. The second match of the Solar System Championship is going to take place, however, the boys are challenged by the climate of Mars which is very different from that of Earth. Will Ronni-Romario and his team mates be able to beat the horned aliens from Mars? Ronni-Romario and the Soccer Planets - Mars Versus Earth is the second book in a space adventure series about soccer, team spirit and friendship. Ronni-Romario and the Soccer Planets are the coolest soccer books in the universe. – Robinio, 11 years old