SETI

The search for life beyond Earth focuses on two main questions: (1) Has intelligent life evolved elsewhere in the cosmos? (2) Has life in any form (microbial) emerged on exoplanets or moons? The Drake Equation (1961) estimated the number of communicative civilizations in the Milky Way at N = R × f_p × n_e × f_l × f_i × f_c × L, yielding estimates from 1 to 1 million civilizations depending on parameter assumptions. Yet 70 years of SETI (Search for Extraterrestrial Intelligence) has found no confirmed signals. Meanwhile, exoplanet discoveries (5,500+ as of 2026) reveal that habitable-zone Earth-like planets are common. Mars, Europa, and Enceladus show signs of liquid water and reduced carbon compounds. JWST observations have detected biosignature candidates in exoplanet atmospheres. The paradox is stark: habitable worlds appear common, yet no confirmed biosignatures have been found. This article reviews the evidence for habitable zones, biosignature detection, and the Fermi Paradox.

On August 15, 1977, a radio telescope in Ohio detected a signal so precisely matched to the expected frequency of extraterrestrial contact that the astronomer who found it circled it in red ink and wrote one word. The signal never repeated. Nearly five decades later, astronomers still cannot fully agree on what caused it.

The Drake Equation estimates how many alien civilizations exist in the Milky Way. Learn each factor, the modern numbers, and what it actually tells us.

If the galaxy has 100 billion stars and is 13.8 billion years old, where is everyone? Eleven serious answers to the Fermi Paradox.

Liu Cixin's chilling answer to the Fermi paradox: the universe is a silent hunt, and broadcasting your location is suicide. Here's the theory.

What's actually on the gold disc bolted to Voyager 1 and 2, how aliens could play it, and where the spacecraft are headed next.

Dyson spheres aren't solid shells — they're swarms of solar collectors around a star. Here's how they'd work, why we'd build one, and how we'd spot aliens using one.

A thought experiment on alien biology, first contact protocols, and Fermi paradox resolutions — what discovering extraterrestrial life would really mean.

AI is already scanning billions of radio signals, analyzing atmospheric data, and searching exoplanet spectra. What happens the day it finds something that shouldn't be there?

From the MeerKAT array to Breakthrough Listen, machine learning is transforming how radio telescopes search for extraterrestrial intelligence — and strange cosmic phenomena.

Confirmed contact with an intelligent alien civilization wouldn't just be a science headline. It would trigger a decades-old international protocol, test the resilience of every major religion, and replay a pattern human societies have lived through before: first contact between civilizations of unequal power.

The search for extraterrestrial intelligence (SETI) has listened for technological signals since Project Ozma in 1960. It now spans radio telescopes, laser searches, and surveys for other technosignatures. No confirmed signal has been found, and the best-known candidates, from the 1977 Wow! signal to BLC1, remain unexplained or were traced to interference.