<Tr> <Th> Volume </Th> <Td> 7020163180000000000 ♠ 1.6318 × 10 km (0.151 Earths) </Td> </Tr> <Tr> <Th> Mass </Th> <Td> 7023641710000000000 ♠ 6.4171 × 10 kg (0.107 Earths) </Td> </Tr> <Tr> <Th> Mean density </Th> <Td> 3.9335 g / cm (0.1421 lb / cu in) </Td> </Tr> <Tr> <Th> Surface gravity </Th> <Td> 3.711 m / s (12.18 ft / s; 0.376 g) </Td> </Tr>

What is a person who studies mars called