Key Concepts in Astrobiology, Xenobiology, and Exobiology
The word Astrobiology is derived from the Greek word “Astron,” which means “constellation star’” “bios,” which means life, and “logia,” which means study. A Russian astronomer named Gavrill Tikhov introduced the term “Astrobiology,” for the first time in 1953.
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The branch of biology that deals extensively with the study of earth and space is astrobiology. The word astrobiology was formerly known as exobiology. It is a scientific discipline that concerns the origin, evolution, distribution, and future of life in the universe.
This page provides an introduction to Astrobiology, exobiology, and astrobiology.
Introduction to Astrobiology
Astrobiology also helps us detect whether extraterrestrial life (life beyond Earth) exists or not. If it does, how humans can detect it.
Now, Let Us Give an Introduction to Nasa Astrobiology:
For decades, astronomers have been searching for the existence of a life other than the Earth. They discover that the presence of another life suffuses our entertainment and culture, and we humans seem to have an innate hope that we are not alone in the universe.
However, astronomers don’t have proof of whether extraterrestrial life exists or not and it still remains a fiction.
So, How Can We Determine the Existence of a Sister Earth?
What is Astrobiology?
Astrobiology is also called exobiology or xenobiology. It is a multidisciplinary branch that deals with nature, existence, and the search for life beyond the Earth. Astrobiology incorporates areas of biology, astronomy, and geology.
What Astrobiology Makes Use of?
Astrobiology employs astronomy, biology, biophysics, biochemistry, chemistry, physical cosmology, exoplanet ology, and geology to research the likelihood of life on other worlds and helps us identify biospheres that may vary from that on Earth.
The origin and early evolution of life are entangled parts of the discipline of astrobiology.
Astrobiology concerns itself with the interpretation of existing scientific data, and although speculation is entertained to offer context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific theories.
This interdisciplinary field embraces research on the origin of planetary systems, organic compounds in space, rock-water-carbon interactions, abiogenesis on Earth, planetary habitability, the research on biosignatures for all times detection, and studies on the potential for an entire period to adapt to challenges on Earth and space.
Existence of Another Life
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Firstly, the existence of another life can be possible by exploring and illuminating the world of extreme life on Earth.
Secondly, by experimenting with the origin of our life.
Thirdly, by understanding more about the chemical makeup of the cosmos.
Lastly, by testing for habitability on missions to Mars, Saturn’s moon Titan, and beyond, an enormous body of science has already been assembled to research and explain the origins, characteristics, and possible extraterrestrial dimensions of life.
Exobiology and Astrobiology
Exobiology and Astrobiology are little different words. Now, let’s understand the difference between the two.
A molecular biologist and Nobel Prize winner Joshua Lederberg coined the term “Exobiology.”
Exobiology features a narrow scope limited to an inquiry of life external to Earth, whereas the topic area of astrobiology is wider and it investigates the link between life, and therefore, the universe, which incorporates the look for extraterrestrial life, but also includes the study of life on Earth, its origin, evolution, and limits.
There’s another term used in place of Astrobiology; let’s understand what Xenobiology is.
Astrobiology and Xenobiology
The term “Xenobiology,” was used long back. It means "biology of the foreigners."
A science fiction writer named Robert Heinlein used the word “Xenobiology,” in 1954 in his work The Star Beast.
However, at present, this term is used in a more specialized sense, to reinstate "biology based on foreign chemistry", of extraterrestrial or terrestrial (possibly synthetic) origin.
For instance, the rover Curiosity has firmly ascertained that ancient Mars was significantly more wet and warm, and was a completely habitable place for microbial life.
All the ingredients needed for all times as we all know it – the right chemicals, a uniform source of energy, and water that was likely present and stable on the surface for many years – were clearly present.
Now, let’s understand the real-life example that is in the air on the Astrobiology Magazine:
Mission Orbiter Mass
The experiment made by ISRO on Mars mission to determine the existence of life on Mars was unsuccessful because scientists lost its communication with the Rover “Pragyaan,” along with its lander, “Vikram.”
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However, ISRO is unstoppable. It is going to launch Gaganyaan in 2021 taking humans in space.
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ISRO was supposed to launch Chandrayaan - 2 missions for a soft landing on the Moon; however, the lander “Vikram,” of this mission is accurately located (established its existence) but its certainty is a big question mark hitherto.
Chandrayaan - 2 was able to produce the thermal image of the Vikram lander with its location 2.1 Km above the Moon’s surface; however, the communication with it is yet to be established.
Because of this reason, mission Chandrayaan - 2 is not completely ready for future ISRO missions (90% ready).
The best part is yet to come when Gangyaan (as per expectation) will be launched in December 2021 with the following four objectives to accomplish:
Study the Martian atmosphere
Study the features of the Martian Surface
Morphology
Mineralogy
So, do you know what Astrobiology Magazine is all about? If not, let’s end our page with its definition:
Astrobiology Magazine
Astrobiology Magazine is especially for exploring the solar system and beyond through reading and viewing images. It is also known as Astrobiology Mag.
Astrobiology Mag is an American, formerly NASA-sponsored, international online popular science magazine that comprises popular science content, referring to articles for the general reader on science and technology subjects.
FAQs on Astrobiology: Life Beyond Earth
1. What is astrobiology?
Astrobiology is a modern, interdisciplinary scientific field focused on studying the origin, evolution, distribution, and future of life in the universe. It addresses fundamental questions like "Are we alone in the universe?" by combining knowledge from biology, chemistry, astronomy, and geology to search for habitable environments and signs of life beyond Earth.
2. What are the main scientific fields that contribute to astrobiology?
Astrobiology is built upon several core scientific disciplines:
Astronomy: Helps in discovering and characterising exoplanets (planets outside our solar system) and identifying those within a star's 'habitable zone'.
Biology: Studies life on Earth, especially extremophiles (organisms living in extreme conditions), to understand the potential limits and adaptability of life.
Chemistry: Investigates the chemical processes that could lead to the origin of life (abiogenesis) and the molecular building blocks necessary for it.
Geology: Examines the geology of planets and moons to determine their history, composition, and potential to support life, for example, by looking for evidence of past water.
3. Why is the study of extremophiles on Earth so important for astrobiology?
The study of extremophiles—organisms that survive in extreme environments like volcanic vents, deep-sea trenches, or arctic ice—is crucial because they expand our understanding of the conditions under which life can exist. By showing that life can thrive without sunlight, in high radiation, or at extreme temperatures, these organisms provide a model for the types of life that might exist on other planets and moons, which we consider hostile by human standards.
4. How do scientists search for signs of life on other planets like Mars?
Scientists search for signs of life, known as biosignatures, rather than looking for living organisms directly. This involves several methods:
Robotic Missions: Rovers like NASA's Perseverance analyse Martian soil and rock samples to find chemical fossils or organic molecules that could indicate past life.
Atmospheric Analysis: Telescopes study the atmospheres of exoplanets for gases like oxygen, methane, or others that, in certain combinations, could be produced by biological processes.
Studying Meteorites: Scientists analyse meteorites from Mars that have landed on Earth for organic compounds or microfossils.
5. What is the difference between astrobiology and astrophysics?
While related, these fields have different primary goals. Astrophysics is the branch of astronomy that studies the physical and chemical properties of celestial objects and the universe itself, focusing on stars, galaxies, gravity, and cosmic phenomena. In contrast, Astrobiology uses the data from astrophysics (like a planet's temperature and atmosphere) to specifically investigate the potential for life. In short, astrophysics studies the cosmos, while astrobiology studies life within the cosmos.
6. What does an astrobiologist do on a typical day?
The work of an astrobiologist is highly varied. It can involve analysing data from space telescopes like the James Webb Space Telescope, conducting laboratory experiments to simulate conditions on other planets, studying meteorites for organic compounds, or participating in fieldwork in extreme environments on Earth that mimic extraterrestrial locations, such as Antarctica or the Atacama Desert.
7. What are the educational qualifications required to become an astrobiologist in India?
There is no direct undergraduate degree in astrobiology in India. The typical path involves:
A strong foundation in Physics, Chemistry, and Biology/Mathematics at the 10+2 level.
A bachelor's degree (B.Sc. or B.Tech) in a core science like Physics, Biology, Chemistry, or Geology.
A master's degree and ultimately a Ph.D. in a specialised area such as planetary science, astrophysics, or microbiology, with a research focus on astrobiological questions.
8. What are some examples of potential habitats for extraterrestrial life within our own solar system?
While Earth is the only known planet with life, scientists have identified several other promising locations in our solar system:
Mars: Evidence suggests it had liquid water in its past, and there might still be subsurface water, making it a prime candidate for past or present microbial life.
Europa (a moon of Jupiter): Believed to have a vast liquid water ocean beneath its icy shell, potentially warmed by tidal forces.
Enceladus (a moon of Saturn): This moon actively sprays plumes of water, ice, and organic molecules from its subsurface ocean into space, providing direct samples to study.
Titan (a moon of Saturn): Has liquid methane lakes and a thick, complex atmosphere rich in organic compounds.
9. What are the career prospects for astrobiologists at agencies like NASA or ISRO?
Career prospects in astrobiology are highly competitive but growing. Major space agencies like NASA and the ESA are the largest employers, hiring astrobiologists for mission planning, data analysis, and research. In India, organisations like ISRO and research institutes such as the Tata Institute of Fundamental Research (TIFR) offer opportunities. Most roles are research-based and typically require a Ph.D.
