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Active SETI
Active SETI (Active Search for Extra-Terrestrial Intelligence) are attempts to send messages to intelligent extraterrestrial life. Active SETI messages are predominantly sent in the form of radio signals. Physical messages like that of the Pioneer plaque may also be considered an active SETI message. Active SETI is also known as METI (Messaging to Extra-Terrestrial Intelligence). Whether humans should engage in Active SETI is controversial due to concerns about potential impacts of extraterrestrial contact, sparking a vigorous policy debate. History 'Active SETI' was a term as early as 2005, though some decades after the term SETI. The term METI was coined in 2006 by Russian scientist Alexander Zaitsev, who proposed a subtle distinction between Active SETI and METI: Concern over METI was raised by the science journal ''Nature'' in an editorial in October 2006, which commented on a recent meeting of the International Academy of Astronautics SETI study group. The editor sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecibo Observatory Aerial View
Arecibo (; ) is a Arecibo barrio-pueblo, city and Municipalities of Puerto Rico, municipality on the northern coast of Puerto Rico, on the shores of the Atlantic Ocean, located north of Utuado, Puerto Rico, Utuado and Ciales, Puerto Rico, Ciales; east of Hatillo, Puerto Rico, Hatillo; and west of Barceloneta, Puerto Rico, Barceloneta and Florida, Puerto Rico, Florida. It is about west of San Juan, Puerto Rico, San Juan, the capital city. Arecibo is the largest municipality in Puerto Rico by area, and it is the core city of the Puerto Rico statistical areas, Arecibo Metropolitan Statistical Area and part of the greater San Juan–Caguas–Guaynabo metropolitan area, San Juan–Bayamón, PR Combined statistical area, Combined Statistical Area. It is spread over 18 ''barrios'' and Arecibo barrio-pueblo, Arecibo Pueblo (the downtown area and the administrative center of the city). Its population in 2020 was 87,754. The Arecibo Observatory, which housed the Arecibo telescope, the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berkeley SETI Research Center
The Berkeley SETI Research Center (BSRC) conducts experiments searching for optical and electromagnetic transmissions from intelligent extraterrestrial civilizations. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globular Cluster M13
Messier 13, or M13 (also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules, the Hercules Globular Cluster, or the Great Hercules Cluster), is a globular cluster of several hundred thousand stars in the constellation of Hercules. Discovery and visibility Messier 13 was discovered by Edmond Halley in 1714, and cataloged by Charles Messier on June 1, 1764, into his list of objects not to mistake for comets; Messier's list, including Messier 13, eventually became known as the Messier catalog. It is located at right ascension 16h 41.7m, declination +36° 28'. Messier 13 is often described by astronomers as the most magnificent globular cluster visible to northern observers. About one third of the way from Vega to Arcturus, four bright stars in Hercules form the Keystone asterism, the broad torso of the hero. M13 can be seen in this asterism of the way north ( by west) from Zeta to Eta Herculis. With an apparent magnitude of 5.8, Messier 13 may be visib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecibo Message
The Arecibo message is an interstellar radio message carrying basic information about humanity and Earth that was sent to the globular cluster Messier 13 in 1974. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials. The message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo Telescope in Puerto Rico on 16 November 1974. The message was aimed at the current location of M13, about 25,000 light years from Earth, because M13 was a large and relatively close collection of stars that was available in the sky at the time and place of the ceremony. When correctly translated into graphics, characters, and spaces, the 1,679 bits of data contained within the message form the image shown here. Description The content of the Arecibo message was designed by a group of Cornell University and Arecibo scientists: Frank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-shift Keying
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is encoded on a carrier signal by periodically shifting the frequency of the carrier between several discrete frequencies. The technology is used for communication systems such as telemetry, weather balloon radiosondes, caller ID, garage door openers, and low frequency radio transmission in the VLF and ELF bands. The simplest FSK is binary FSK (BFSK, which is also commonly referred to as 2FSK or 2-FSK), in which the carrier is shifted between two discrete frequencies to transmit binary (0s and 1s) information. Modulating and demodulating Reference implementations of FSK modems exist and are documented in detail. The demodulation of a binary FSK signal can be done using the Goertzel algorithm very efficiently, even on low-power microcontrollers. Variations Multiple frequency-shift keying Continuous-phase frequency-shift keying In principle FSK can be implemented by usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Call
Cosmic Call was the name of two sets of interstellar radio messages that were sent from RT-70 in Yevpatoria, Ukraine in 1999 (Cosmic Call 1) and 2003 (Cosmic Call 2) to various nearby stars. The messages were designed with noise-resistant format and characters. The project was funded by Team Encounter, a Texas-based startup, which went out of business in 2004. Both transmissions were at ~150 kW, 5.01 GHz ( FSK +/-24 kHz). Message structure Each Cosmic Call 1 session had the following structure. The Scientific Part (DDM, BM, AM, and ESM) was sent three times (at 100 bit/s), and the Public Part (PP) was sent once (at 2000 bit/s), according to the following arrangement: :DDM → BM → AM → ESM → DDM → BM → AM → ESM → DDM → BM → AM → ESM → PP, where DDM is thDutil-Dumas Message created by Canadian scientists Yvan Dutil and Stéphane Dumas, BM is the Braastad Message, AM is the Arecibo Message, and ESM is the Encounter 2001 Staff Message. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecibo Observatory
The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science Foundation (NSF). The observatory's main instrument was the Arecibo Telescope, a spherical reflector dish built into a natural sinkhole, with a cable-mount steerable receiver and several radar transmitters for emitting signals mounted above the dish. Completed in 1963, it was the world's largest single-aperture telescope for 53 years, surpassed in July 2016 by the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. On August 10 and November 6, 2020, two of the receiver's support cables broke and the NSF announced that it would decommission the telescope. The telescope collapsed on December 1, 2020. In 2022, the NSF announced the telescope will not be rebuilt, with an educational facility to be established on the site. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Drake
Frank Donald Drake (May 28, 1930 – September 2, 2022) was an American astrophysicist and astrobiologist. He began his career as a radio astronomer, studying the planets of the Solar System and later pulsars. Drake expanded his interests to the search for extraterrestrial intelligence (SETI), beginning with Project Ozma in 1960, an attempt at extraterrestrial communication. He developed the Drake equation, Physics Today 14 (4), 40–46 (1961). which attempts to quantify the number of intelligent lifeforms that could potentially be discovered. Working with Carl Sagan, Drake helped to design the Pioneer plaque, the first physical message flown beyond the Solar System, and was part of the team that developed the Voyager Golden Record. Drake designed and implemented the Arecibo message in 1974, an extraterrestrial radio transmission of astronomical and biological information about Earth. He is the father of Advanced SETI. Drake worked at the National Radio Astronomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lone Signal
Lone Signal was a crowdfunded active SETI project designed to send interstellar messages from Earth to a possible extraterrestrial civilization. Founded by businessman Pierre Fabre and supported by several entrepreneurs, Lone Signal was based at the Jamesburg Earth Station in Carmel, California. The project's beacon, which commenced continuous operations on June 17, 2013, transmitted short, 144-character messages by citizens of Earth to the red dwarf star Gliese 526, located 17.6 light-years away from Earth in the constellation Boötes. Gliese 526 has no known planets. The Lone Signal team hoped to earn million to construct a network of satellite dishes across the Earth's surface, which could beam messages to many regions of the Milky Way galaxy. The project ceased transmission shortly after it began, due to lack of funding, having operated roughly from June to August 2013. Message components Lone Signal's message design had two components: a binary unmodulated hailing co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Security
Security is protection from, or resilience against, potential harm (or other unwanted coercion). Beneficiaries (technically referents) of security may be persons and social groups, objects and institutions, ecosystems, or any other entity or phenomenon vulnerable to unwanted change. Security mostly refers to protection from hostile forces, but it has a wide range of other senses: for example, as the absence of harm (e.g., freedom from want); as the presence of an essential good (e.g., food security); as resilience against potential damage or harm (e.g. secure foundations); as secrecy (e.g., a secure telephone line); as containment (e.g., a secure room or cell); and as a state of mind (e.g., emotional security). Security is both a feeling and a state of reality. One might feel secure when one is not actually so; or might feel insecure despite being safe. This distinction is usually not very clear to express in the English language. The term is also used to refer to acts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics (computer science), semantics, and synchronization of communication and possible Error detection and correction, error recovery methods. Protocols may be implemented by Computer hardware, hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be Implementation, implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
