English
Related papers

Related papers: Can Collimated Extraterrestrial Signals be Interce…

200 papers

The search for extraterrestrial intelligence by looking for signals from advanced technological civilizations has been ongoing for some decades. We suggest that it could possibly be made more efficient by focusing on stars from which the…

Earth and Planetary Astrophysics · Physics 2009-03-10 Shmuel Nussinov

The Defense Department and NASA are investigating the possibility that aliens are currently surveilling Earth. This aligns with some search-for-extraterrestrial-intelligence (SETI) theorists who have concluded that ET's best strategy for…

Popular Physics · Physics 2023-08-30 John Gertz

If the signals that are being sought in SETI programs do exist but are very brief, for example because they are produced intermittently to conserve energy, then it is essential to know when these signals will arrive at the Earth. Different…

Astrophysics · Physics 2009-11-07 Robin H. D. Corbet

The modern search for extraterrestrial intelligence (SETI) began with the seminal publications of Cocconi & Morrison (1959) and Schwartz & Townes (1961), who proposed to search for narrow-band signals in the radio spectrum, and for optical…

Instrumentation and Methods for Astrophysics · Physics 2021-07-27 Michael Hippke

The possibility that extraterrestrial intelligences (ETIs) could be hostile to humanity has been raised as a reason to avoid even trying to contact ETIs. However, there is a distinct shortage of analytical discussion about the risks of an…

Popular Physics · Physics 2013-02-05 Janne M. Korhonen

Land-based beacons, information laden probes sent into our solar system, and more distal communication nodes have each been proposed as the most likely means by which we might be contacted by ET. Each method, considered in isolation from…

Popular Physics · Physics 2021-06-09 John Gertz

The Search for Extraterrestrial Intelligence (SETI) has thus far failed to provide a convincing detection of intelligent life. In the wake of this null signal, many "contact pessimistic" hypotheses have been formulated, the most famous of…

Earth and Planetary Astrophysics · Physics 2010-04-19 Duncan H. Forgan , Ken Rice

Many hypotheses have been raised to explain the famous Fermi paradox. One of them is that self-replicating probes could have explored the whole Galaxy, including our Solar System, and that they are still to be detected. In this scenario, it…

Popular Physics · Physics 2013-10-01 M. Gillon

The Search for Extraterrestrial intelligence (SETI) is a scientific and cultural effort seeking evidence of intelligent life beyond earth. Radio SETI observes the radio spectrum for ''technosignatures" that could be produced by an advanced…

Instrumentation and Methods for Astrophysics · Physics 2021-09-29 Kenneth M. Houston , Andrew P. V. Siemion , Steve Croft

The search for technosignatures from hypothetical galactic civilizations is going through a new phase of intense activity. For the first time, a significant fraction of the vast search space is expected to be sampled in the foreseeable…

Instrumentation and Methods for Astrophysics · Physics 2019-03-26 Claudio Grimaldi , Geoffrey W. Marcy

In the search for extraterrestrial intelligence (SETI), the highly incomplete sampling of the technosignature search space is often considered as a plausible explanation for the persistent lack of detections over six decades of searches. If…

Instrumentation and Methods for Astrophysics · Physics 2026-02-23 Claudio Grimaldi

The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar…

Popular Physics · Physics 2019-01-31 Kelvin F Long

Exoplanetary systems are prime targets for the Search for Extraterrestrial Intelligence (SETI). With the recent uptick in the identification of candidate and confirmed exoplanets through the work of missions like the Transiting Exoplanet…

We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design…

The search for extraterrestrial intelligence (SETI) targeted searches aim to observe specific areas and objects to find possible technosignatures. Many SETI researches have focused on nearby stars and their planets in recent years. In this…

Instrumentation and Methods for Astrophysics · Physics 2025-04-10 Xiao-Hang Luan , Bo-Lun Huang , Zhen-Zhao Tao , Yan Cui , Tong-Jie Zhang , Pei Wang

The Search for Extraterrestrial Intelligence (SETI) has heretofore been a largely passive exercise, reliant on the pursuit of technosignatures. Still, there are those that advocate a more active approach. Messaging Extraterrestrial…

Popular Physics · Physics 2020-08-11 T. Cortellesi

What would SETI Beacon transmitters be like if built by civilizations with a variety of motivations, but who cared about cost? We studied in a companion paper how, for fixed power density in the far field, we could build a cost-optimum…

Popular Physics · Physics 2010-03-05 Gregory Benford , James Benford , Dominic Benford

As our ability to undertake more powerful Searches for Extraterrestrial Intelligence (SETI) grows, so does interest in the more controversial endeavour of Messaging Extraterrestrial Intelligence (METI). METI proponents point to the SETI…

Earth and Planetary Astrophysics · Physics 2021-01-06 Eamonn Kerins

A formula is proposed to quantitatively estimate the signal emission rate of Communicating Extra-Terrestrial Intelligent civilizations (CETIs) in the Galaxy. I suggest that one possible type of CETI signal would be brief radio bursts…

Popular Physics · Physics 2020-11-10 Bing Zhang

Detection of signals from a possible extrasolar technological civilization is one of the challenging efforts of science. In this work, we propose using natural telescopes made of single or binary gravitational lensing systems to magnify…

Instrumentation and Methods for Astrophysics · Physics 2016-08-31 Sohrab Rahvar