It is certainly possible for rocky planets, similar to Earth, to be inhabited by intelligent alien species. The conditions necessary for life as we know it, including the presence of liquid water, an atmosphere, and suitable temperatures, are often found on rocky planets within a star's habitable zone. The habitable zone refers to the region around a star where conditions may allow for the existence of liquid water on a planet's surface.
However, it's important to note that the specific conditions required for life can vary, and the potential for life on other planets depends on various factors. While some planets within the habitable zone may have conditions suitable for life, others may be too hot, too cold, or lack other essential elements necessary to support life as we understand it.
It's also important to consider that life on other planets might not necessarily resemble life on Earth. Alien life forms could have adapted to thrive in environments that we would consider extreme or inhospitable. They might have different biochemistry or rely on alternative energy sources.
Our understanding of habitable environments and the potential for extraterrestrial life is continually evolving, and ongoing research and future space missions will provide us with more insights. While we have yet to discover conclusive evidence of intelligent alien life, the vastness of the universe suggests that the possibility of other intelligent civilizations exists.