Astrobiology

Astrobiology is an interdisciplinary field, combining aspects of astronomy, biology and geology, which is focused primarily on the study of the origin, distribution and evolution of life. It comes from the Greek words astron = star, bios = life and logos = word/science), and is also known as exobiology (Greek: exo = out) or xenobiology (Greek: xenos = foreign). Some major astrobiological research topics include: What is life? How did life arise on Earth? What kind of environments can life tolerate? How can w ...

Including:

• Astrobiology - Overview
• Astrobiology - Research Outcomes
• Astrobiology - Methodology
• Astrobiology - Narrowing the task
• Astrobiology - The sciences of Astrobiology
• Astrobiology - Criticisms
• Astrobiology - Publications

Read more here: » Astrobiology: Encyclopedia - Astrobiology

Astrobiology - Narrowing the task. Main article: Planetary habitability When looking for life in other planets, some simplifying assumptions are useful to reduce the size of the task of astrobiologists. One is to assume that the vast majority of life-forms in our galaxy are based on carbon chemistries, as are all life-forms on Earth. While it is possible that non carbon-based life exists, carbon is well known for the unusually wide variet ...

See also:

Astrobiology, Astrobiology - Overview, Astrobiology - Research Outcomes, Astrobiology - Methodology, Astrobiology - Narrowing the task, Astrobiology - The sciences of Astrobiology, Astrobiology - Criticisms, Astrobiology - Publications

Read more here: » Astrobiology: Encyclopedia II - Astrobiology - Methodology

Alternative biochemistry collectively refers to an assortment of astrobiology theories and hypotheses in which life is based on chemical systems other than those used by currently known forms of life. Proponents of such theories sometimes use the expression carbon chauvinism to disparage the assumption that carbon molecules are necessarily the basis for all life. Up to this point, however, no non-carbon based life-form has been discovered. Alternative biochemistry - Silicon biochemistry. The most com ...

Including:

• Alternative biochemistry - Silicon biochemistry
• Alternative biochemistry - Nitrogen/Phosphorus biochemistry
• Alternative biochemistry - Other exotic biochemical elements
• Alternative biochemistry - Non-water solvents
• Alternative biochemistry - Ammonia
• Alternative biochemistry - Other solvents
• Alternative biochemistry - Artificial life
• Alternative biochemistry - In fiction

Read more here: » Alternative biochemistry: Encyclopedia - Alternative biochemistry

Mars is the fourth planet from the Sun in our solar system. It is named after Mars, the Roman god of war (Ares in Greek mythology). Its name was chosen because of its red color, a feature that also earned it the nickname "The Red Planet". Mars has two moons, Phobos and Deimos, both are small and oddly-shaped, each possibly being captured asteroids. The prefix areo- refers to Mars in the same way geo- refers to Earth—for example, areology versus geology. (Areology is also used to refer to the study of Mars as a whole rather than ju ...

Including:

• Mars - Mythology
• Mars - Physical characteristics
• Mars - Atmosphere
• Mars - Geology
• Mars - Topography
• Mars - Canals
• Mars - Ice patches
• Mars - The moons of Mars
• Mars - The exploration of Mars
• Mars - Nomenclature
• Mars - Early nomenclature
• Mars - Modern nomenclature
• Mars - Observation of Mars
• Mars - Appearance
• Mars - Martian meteorites
• Mars - Life on Mars
• Mars - The Mars flag
• Mars - Mars in fiction

Read more here: » Mars: Encyclopedia - Mars

Extraterrestrial life is life that may exist and originate outside the planet Earth. Its existence is currently hypothetical: there is as yet no evidence of extraterrestrial life that has been widely accepted by scientists. Most scientists hold that if extraterrestial life exists, its evolution would have occurred independently in different places in the universe. An alternative hypothesis, held by a minority, is panspermia, which suggests that life in the universe could have stemmed from a single initial distribution of spores ...

Including:

• Extraterrestrial life - Possible basis of extraterrestrial life
• Extraterrestrial life - Biochemistry
• Extraterrestrial life - Theoretical Evolution and Morphology
• Extraterrestrial life - Beliefs in extraterrestrial life
• Extraterrestrial life - Ancient and Early Modern ideas
• Extraterrestrial life - Extraterrestrials and the Modern era
• Extraterrestrial life - Scientific search for extraterrestrial life
• Extraterrestrial life - Direct search
• Extraterrestrial life - Indirect search
• Extraterrestrial life - Extraterrestrial life in the Solar System
• Extraterrestrial life - Dealing with extraterrestrial life
• Extraterrestrial life - Related books and media

Read more here: » Extraterrestrial life: Encyclopedia - Extraterrestrial life

Each NASA Viking Lander carried three biological experiments to the surface of Mars in the late 1970s. These were the first experiments used specifically to look for biosignatures on another planet. The three experiments all looked for changes in chemical composition of the atmospheric gasses trapped over a sample of Martian soil as it was exposed to different temperatures, chemical substances, and other conditions. In general, the results were negative for signs of life, although one of the three experiments gave an initial po ...

Including:

• Viking biological experiments - Background
• Viking biological experiments - The experiments
• Viking biological experiments - Pyrolytic release
• Viking biological experiments - Labeled Release
• Viking biological experiments - Gas Exchange
• Viking biological experiments - Gas Chromatograph - Mass Spectrometer
• Viking biological experiments - The Results
• Viking biological experiments - Scientific conclusions and ongoing debate

Read more here: » Viking biological experiments: Encyclopedia - Viking biological experiments

An understanding of planetary habitability begins with stars, not planets themselves. While bodies that are generally Earth-like may be plentiful, it is just as important that their larger system be agreeable to life. Under the auspices of SETI's Project Phoenix, scientists Margaret Turnbull and Jill Tarter developed the "HabCat" (or Catalogue of Habitable Stellar Systems) in 2002. The catalogue was formed by winnowing the nearly 120,000 stars of the larger Hipparcos Catalogue into a core group of 17,000 "HabStars," and the selection criteri ...

See also:

Planetary habitability, Planetary habitability - Suitable star systems, Planetary habitability - Spectral class, Planetary habitability - A stable habitable zone, Planetary habitability - Low stellar variation, Planetary habitability - High metallicity, Planetary habitability - Binary systems, Planetary habitability - Planetary characteristics, Planetary habitability - Mass, Planetary habitability - Orbit and rotation, Planetary habitability - Geochemistry, Planetary habitability - Other considerations, Planetary habitability - The habitability of red dwarf planetary systems, Planetary habitability - Good Jupiters, Planetary habitability - The Galactic neighborhood, Planetary habitability - Notes

Read more here: » Planetary habitability: Encyclopedia II - Planetary habitability - Suitable star systems

The red, fiery appearance of Mars is caused by iron oxide (rust) on its surface. Mars has only a quarter the surface area of the Earth and only one-tenth the mass, though its surface area is approximately equal to that of the Earth's dry land because Mars lacks oceans. The solar day (or sol) on Mars is very close to Earth's day: 24 hours, 39 minutes, and 35.244 seconds. Mars - Atmosphere. Mars' atmosphere is thin: the air pressure on the surface is only 750 pascals, about 0.75% of the average on Ear ...

See also:

Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Physical characteristics

SETI - Early work. In 1960, Cornell University astronomer Frank Drake performed the first modern SETI experiment, named "Project Ozma", after the Queen of Oz in L. Frank Baum's fantasy books. Drake used a 25-meter-diameter radio telescope at Green Bank, West Virginia, to examine the stars Tau Ceti and Epsilon Eridani near the 1.420 gigahertz marker frequency. A 400 kilohertz band was scanned around the marker frequency, using a single-channel receiver with a bandwidth of 100 hertz. The information was stored on tape for off-line ...

See also:

SETI, SETI - Overview, SETI - Radio SETI experiments, SETI - Early work, SETI - Arecibo message, SETI - SERENDIP Sentinel META and BETA, SETI - MOP and Project Phoenix, SETI - Allen Telescope Array, SETI - SETI@home, SETI - Optical SETI experiments, SETI - Probe SETI and SETA Experiments, SETI - Where are they? / The interstellar Internet, SETI - Public information, SETI - Criticism of SETI

Read more here: » SETI: Encyclopedia II - SETI - Radio SETI experiments

The design package included three biological experiments plus a fourth which was not limited to biological experiments but served dual purposes. The Biology payload weighed only 15.5 kg (34.2 lb) and consumed on average only 15 watts of power. Viking biological experiments - Pyrolytic release. The Pyrolytic Release or PR experiment looked for evidence of photosynthesis by incubating Martian soil with light, water, and a carbon-containing atmosphere of either CO or CO2. The carbon-b ...

See also:

Viking biological experiments, Viking biological experiments - Background, Viking biological experiments - The experiments, Viking biological experiments - Pyrolytic release, Viking biological experiments - Labeled Release, Viking biological experiments - Gas Exchange, Viking biological experiments - Gas Chromatograph - Mass Spectrometer, Viking biological experiments - The Results, Viking biological experiments - Scientific conclusions and ongoing debate

Read more here: » Viking biological experiments: Encyclopedia II - Viking biological experiments - The experiments

SETI - Early work. In 1960, Cornell University astronomer Frank Drake performed the first modern SETI experiment, named "Project Ozma", after the Queen of Oz in L. Frank Baum's fantasy books. Drake used a 25-meter-diameter radio telescope at Green Bank, West Virginia, to examine the stars Tau Ceti and Epsilon Eridani near the 1.420 gigahertz marker frequency. A 400 kilohertz band was scanned around the marker frequency, using a single-channel receiver with a bandwidth of 100 hertz. The information was stored on tape for off-line ...

See also:

SETI, SETI - Overview, SETI - Radio SETI experiments, SETI - Early work, SETI - Arecibo message, SETI - SERENDIP Sentinel META and BETA, SETI - MOP and Project Phoenix, SETI - Allen Telescope Array, SETI - SETI@home, SETI - Optical SETI experiments, SETI - Probe SETI and SETA Experiments, SETI - Where are they?, SETI - Public information, SETI - Criticism of SETI

Read more here: » SETI: Encyclopedia II - SETI - Radio SETI experiments

The California Institute of Technology (commonly referred to as Caltech) is a private, coeducational university located in Pasadena, California, in the United States. One of the world's premier research universities, Caltech maintains a strong emphasis on the natural sciences and engineering. Caltech also owns and manages the Jet Propulsion Laboratory (JPL), an autonomous-space-flight complex that oversees the design and operation of most of NASA's space-probes. California Institute of Technology - History. Including:

• California Institute of Technology - History
• California Institute of Technology - Academics
• California Institute of Technology - Academic departments
• California Institute of Technology - Undergraduate program
• California Institute of Technology - Student life
• California Institute of Technology - House system
• California Institute of Technology - Traditions

Read more here: » California Institute of Technology: Encyclopedia - California Institute of Technology

Extraterrestrial life - Ancient and Early Modern ideas. See also: Cosmic pluralism Belief in extraterrestrial life may have been present in ancient Egypt, Babylon, and Sumer, although in these societies, cosmology was fundamentally supernatural and the notion of aliens is difficult to distinguish from that of gods, demons, and such. The first important Western thinkers to argue systematically for a universe full of other planets and, therefore, possible extraterrestrial life were the an ...

See also:

Extraterrestrial life, Extraterrestrial life - Possible basis of extraterrestrial life, Extraterrestrial life - Biochemistry, Extraterrestrial life - Theoretical Evolution and Morphology, Extraterrestrial life - Beliefs in extraterrestrial life, Extraterrestrial life - Ancient and Early Modern ideas, Extraterrestrial life - Extraterrestrials and the Modern era, Extraterrestrial life - Scientific search for extraterrestrial life, Extraterrestrial life - Direct search, Extraterrestrial life - Indirect search, Extraterrestrial life - Extraterrestrial life in the Solar System, Extraterrestrial life - Dealing with extraterrestrial life, Extraterrestrial life - Related books and media

Read more here: » Extraterrestrial life: Encyclopedia II - Extraterrestrial life - Beliefs in extraterrestrial life

In the realm of science fiction there have occasionally been forms of life proposed that, while often highly speculative and unsupported by rigorous theoretical examination, are nevertheless interesting and in some cases even somewhat plausible. One of the major sentient species in Terry Pratchett's Discworld universe is Trolls. Their being mineral-based has various interesting effects on their physiology and culture. Trolls eat rocks, which suggests that their biochemistry is similar to that of plants. A heterotrophic silicon-based l ...

See also:

Alternative biochemistry, Alternative biochemistry - Silicon biochemistry, Alternative biochemistry - Nitrogen/Phosphorus biochemistry, Alternative biochemistry - Other exotic biochemical elements, Alternative biochemistry - Non-water solvents, Alternative biochemistry - Ammonia, Alternative biochemistry - Other solvents, Alternative biochemistry - Artificial life, Alternative biochemistry - In fiction

Read more here: » Alternative biochemistry: Encyclopedia II - Alternative biochemistry - In fiction

The red, fiery appearance of Mars is caused by iron oxide (rust) on its surface. Mars has only a quarter the surface area of the Earth and only one-tenth the mass, though its surface area is approximately equal to that of the Earth's dry land because Mars lacks oceans. The solar day (or sol) on Mars is very close to Earth's day: 24 hours, 39 minutes, and 35.244 seconds. Mars - Atmosphere. Mars' atmosphere is thin: the air pressure on the surface is only 750 pascals, about 0.75% of the average on Ear ...

See also:

Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Appearance, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Physical characteristics

A handful of objects are known that are surely meteorites and may be of Martian origin. Two of them may show signs of ancient bacterial activity. On August 6, 1996 NASA announced that analysis of the ALH 84001 meteorite thought to have come from Mars, shows some features that may be fossils of single-celled organisms, although this idea is controversial. In Solar System Research (March 2004, vol 38, page 97) it was suggested tha ...

See also:

Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Martian meteorites

While most SETI sky searches have studied the radio spectrum, some SETI researchers have considered the possibility that alien civilizations might be using powerful lasers for interstellar communications at optical wavelengths. The idea was first suggested in a paper published in the British journal Nature in 1961, and in 1983 Charles Townes, one of the inventors of the laser, published a detailed study of the idea in the US journal Pro ...

See also:

SETI, SETI - Overview, SETI - Radio SETI experiments, SETI - Early work, SETI - Arecibo message, SETI - SERENDIP Sentinel META and BETA, SETI - MOP and Project Phoenix, SETI - Allen Telescope Array, SETI - SETI@home, SETI - Optical SETI experiments, SETI - Probe SETI and SETA Experiments, SETI - Where are they?, SETI - Public information, SETI - Criticism of SETI

Read more here: » SETI: Encyclopedia II - SETI - Optical SETI experiments

Astronomy (Greek: αστρονομία = άστρον + νόμος, astronomia = astron + nomos, literally, "law of the stars") is the science of celestial objects and phenomena that originate outside the Earth's atmosphere, such as stars, planets, comets, galaxies, and the cosmic background radiation. It is concerned with the formation and development of the universe, the evolution and physical and chemical properties of celestial objects and the calculation of their motions. Astronomical observations are ...

Including:

• Astronomy - Divisions
• Astronomy - By subject or problem addressed
• Astronomy - Ways of obtaining information
• Astronomy - History of astronomy
• Astronomy - Timelines in astronomy
• Astronomy - Astronomy tools

Read more here: » Astronomy: Encyclopedia - Astronomy

The depiction of Mars in fiction has been stimulated its dramatic red color and by early scientific speculations that its surface conditions might be capable of supporting life. Until the arrival of planetary probes, the traditional view of Mars derived from the astronomers Percival Lowell and Giovanni Schiaparelli, whose observation of supposedly linear features on the planet created the myth of canals on Mars. For many years, a standard notion of the planet as a drying, cooling, dying world with ancient civilizations constructing ir ...

See also:

Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Mars in fiction

Life is a multi-faceted concept that may refer to the ongoing process of which living things are a part the period between the conception (the point at which the entity can be considered to be an individualized being) and death of an organism the condition of an entity between conception and death that which makes a living thing alive. Life - Defining the concept of life. Life - A conventional definition. In biology, a ...

Including:

• Life - Defining the concept of life
• Life - A conventional definition
• Life - Exceptions to the conventional definition
• Life - Other definitions
• Life - Descent with modification: a useful characteristic
• Life - Origin of life
• Life - The possibility of extraterrestrial life

Read more here: » Life: Encyclopedia - Life