In the past few years, scientists have made huge progress probing ever more deeply into space. They have confirmed the existence of a vast multitude of earth-like planets. They have found evidence of complex chemistry in deep space and validated the claim that all life on Earth is made of stardust. Yet there is still no evidence of life originating anywhere other than on Earth.

This may change soon. Upcoming searches will aim to detect markers of life in the atmospheres of planets outside the solar system. We also have unprecedented technologies to detect signs of intelligent civilizations through industrial pollution of planetary atmospheres, space archaeology of debris from dead civilizations or artifacts such as photovoltaic cells that are used to re-distribute light and heat on the surface of a planet or giant megastructures.

At the same time, we continue to launch interplanetary and even interstellar explorations of our own. Others may notice and seek to contact us --- or we may find messages that confirm we are not alone.

Among the questions: