Sustainability may be an unavoidable feature of advanced civilizations, making advanced technology “indistinguishable from ...

THE KARDASHEV SCALE. We have no idea what an alien civilization would look like. Humans are evolved primates. What if an alien species is reptilian? Or more like an insect? Or a hybrid of these?

When other factors are considered — such as the fraction of hospitable planets that host any life at all and how long a signal-emitting civilization might last — the possibility of many active ...

In the 1960s, physicist Freeman Dyson proposed that advanced alien civilizations could be building out enormous megastructures around a star to harness much of its energy. These shells, dubbed Dyson ...

According to the Drake Equation, which calculates the probability of an existing, communicating civilization, there are currently an estimated 12,500 such intelligent alien societies in the Milky ...

It summarized the results of a NASA workshop on how to detect alien civilizations. What was needed, the assembled group of astronomers, engineers and biologists concluded, was Cyclops, a vast ...

He suggests there's a chance that water or other liquid-dwelling aliens, as well as civilizations on super-Earths, may actually be trapped on their planets due to "physical limitations," even if ...

Don’t bother wondering if alien civilizations can hear our radio broadcasts or not. According to a new study, sufficiently advanced aliens can already see us. The research, set to be published ...

"Our industrial civilization has lasted (so far) roughly 300 years (since, for example, the beginning of mass production methods)," the study writes. In that time, we've left a mark on Earth but ...

Rebecca Charbonneau is a historian at the American Institute of Physics, College Park, Maryland, and the author of Mixed Signals: Alien Communication ... that any civilization leaves for others.