Yes, the surface of Mars is fairly solid; it is sturdy enough to support roving vehicles, for example.
In the Solar System, that would be Mercury, Venus, Earth, Mars.
Mars is a solid (rocky) planet. All the inner planets are solid and Mars is an inner planet.
solid
Solid.
Mars. Both asteroids and Mars are solid and rocky. Jupiter is not solid and has no rocks that we know of.
The surface of Mars is solid. It is strewn with rock and rust colored sand.
Mars is a solid pllanet.
Mars is a solid rocky planet with a red color from the large amount of iron oxide on its surface. That is why NASA has been able to land unmanned landers there.
If you mean planet Mars: solid, mainly.
Mars is made of a solid iron core.
On Solid Ground was created in 1989.
Solid