Astrobiology: The Life Next Door
By Shruti Chousalkar
Cosmofluencer (Season 04)
“Somewhere, something incredible is waiting to be known” – Carl Sagan
We, humans, are always intrigued by the existence of life and its vast forms. From the playful dolphins springing and diving into the sea, the polar bears adapted to living in the freezing temperatures; the immovable autotrophic vegetation, the microscopic bacteria and viruses capable of landing you on a hospital bed, to the most evolved Homo sapiens, life never fails to fascinate us.
Even after decades of research, we are yet to completely understand the origin of life, its extant, and its nature. This was about life on Earth, having its essence in the genetic material that is carried by all the life forms on this planet. Now, let us consider another plane of thought. What if this genetic material isn’t exclusive to life forms only on this planet? What if there exists another dimension to life? Can we augment our understanding of life on Earth by exploring extraterrestrial life? In this colossal universe encompassing a hundred billion galaxies, a few hundred billion stars in each of those galaxies, and overall innumerable planets revolving around their respective stars, how can our curious minds contend with the fact that life evolved only on a single planet?
Frontiersin.org
With advancing space exploration projects and habitability testing missions to Mars, Europa (Jupiter’s moon), Titan (Saturn’s moon), and many more, continuous and consistent efforts are being put up to scrutinize the plausibility of extraterrestrial life. The concept of astrobiology is relatively new but its foundation was laid long ago. Back in 1953, The Miller-Urey Experiment ignited the field of astrobiology, where these two scientists, Stanley Miller and Harold Uray, artificially created the atmosphere of primitive Earth to understand the origin of life, and they became the trailblazers of astrobiology. Keeping the outcome of this experiment in mind, scientists are now studying the atmospheric composition of other planets to assess the likelihood of life.
(Image source: Britannica)
NASA’s 2015 Astrobiology Strategy had six focus points that include:
● Identifying abiotic sources of organic compounds
● Synthesis and function of macromolecules in the origin of life
● Early life and increasing complexity
● Co-evolution of life and the physical environment
● Identifying, exploring, and characterizing environments for habitability and biosignatures
● Constructing habitable worlds.
Pertaining to these key areas, NASA has launched several missions that serve the purpose of astrobiology.
Mars 2020 Mission resulted in the successful landing of the Perseverance rover within the Jezero Crater which hunted for signs of potential life on Mars as well as collected samples of rock and regolith for return to Earth.
Spacenews.com/mars
MAVEN (Mars Atmosphere and Volatile Evolution) was launched from Cape Canaveral on the 18th of November, 2013, and entered Mars’s orbit on the 21st of September, 2014. It studies the Martian atmosphere so that we can understand how the climate has been affected by atmospheric loss and the disappearance of liquid water over time.
Britannica
O/OREOS (Organism/Organic Exposure to Orbital Stresses), a nanosatellite, studies the relationship between living organisms and the space environment. The orbiter carried out two individual astrobiology experiments by booming microorganisms and organic compounds into the Earth’s exosphere to directly study the changes they undergo upon space exposure. Launch date: 20th November 2010.
Wikipedia
INSIGHT (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) studied how rocky planets evolved and detected the crust, mantle, and core of Mars. Launch date: 5th May 2018
Jet Propulsion Lab/NASA
Kepler and K2 missions were launched in 2009 and 2013 respectively, which rummaged for planets outside our solar system. It resulted in the discovery of more than 2600 exoplanets.
NASA Science
LCROSS (Lunar Crater Observation and Sensing Satellite) discovered water ice on the Moon in shadowed craters. It also found useful materials in lunar soil and the existence of a water cycle, indicating that rocky bodies might become habitable in the future. Launch date: 18th June 2009
NASA Science
MARINER 4 had a significant impact on the field of astrobiology when it captured detailed images of the Martian surface, enabling astrobiologists to correlate them with similar landscapes on Earth’s atmosphere.
NASA Astrobiology
VIKING 1 and 2 were the two first-of-its-kind space crafts launched by NASA to search for evidence of life on Mars. Launch date: 20th August 1975 (Viking 1); 9th September 1975 (Viking 2)
NASA Astrobiology
Conclusion
These are some of the initiatives taken up by space scientists to transform our anticipation of contacting our extraterrestrial buddies into reality. As a matter of fact, till now, we have not been able to find any signs of actual life out there in the universe beyond our planet, but the quest goes on. Astrobiologists have just found a flicker of hope in the form of:
● Discovery of exoplanets in the Goldilocks zone
● Biosignatures
● Existence of life in extremophiles and their study
● Moon exploration
● Mars exploration
● Technological advancements
There is no solid reason to halt this exploration at any stage. A thrust needs to be put on by engaging new ideas and great minds in this domain. We have come this far, and as we keep getting leads through our space missions, I hope that this exciting journey continues.
References
- Life In The Universe | Astrobiology At NASA
- Astronomy | Wikipedia
- Satellite Missions | EOPortal