A paramount mission in the intellectually engaging realm of astrobiology is the hunt for an entirely different variety, i.e., extraterrestrial life. Astronomers study the possible life of other planets and how flexible the chances of supporting life are, using equipment and technology in which to seek out potential animal species.
As the age of space exploration progresses, the search for life on other worlds has been transformed into a scientific endeavor that is driven by new discoveries and revolutionary research.
The Groundwork of Astrobiology
Tempe, AZ—Astrobiology is an inherently interdisciplinary science that combines elements of biology, chemistry, geology, and planetary science. The ultimate question is whether life might develop elsewhere in the universe, and what forms of conditions could support its existence.
It is this area of science which has gained the most popularity in recent decades, especially when habitable exoplanets and astronomical bodies have started to get attention.
Extremophiles: Life in Extreme Conditions
One of the key considerations in astrobiology is extremophiles, life forms that grow in extreme circumstances on Earth, like beneath deep-sea hydrothermal vents, around acidic seas, or encased within frozen tundras. Such findings show that life can thrive under conditions once considered absolutely hostile, expanding the range of places where extraterrestrial life may be hiding.
Mars Exploration: The Hunt for Life
Mars is often the prime candidate in astrobiological studies as it shares traits with Earth. Liquid water is thought to have flowed across the Martian surface, pooling in basins and flowing in rivers long enough for life to potentially get a foothold.
Many missions have been sent to explore the planet, most recently NASA’s Perseverance Rover, which landed on Mars in February 2021.
Perseverance and the Search for Biosignatures
While seeking biosignatures, signs of past microbial life, Perseverance will carefully pack selected samples in first-ever tubes for future return to Earth. The mission seeks to shed light on key questions concerning the possibility of life on Mars and the planet’s geological history.
This mission hopes to gain major insights for the next decade and perhaps pave the way for understanding the conditions of life smoldering on Mars.
The Role of Exoplanets in Astrobiology
The discovery of exoplanets (planets outside our solar system) has had a huge impact on the field of astrobiology. Currently, there are more than 5,000 exoplanets that have been confirmed to exist, with thousands of others still awaiting confirmation.
To date, the search for exoplanets where life might reside has been somewhat blessed with success—despite some inevitable false alarms—that focus on identifying those within what is called the habitable zone.
Hope in the Habitable Zone
Recently, scientists found the first exoplanet (a world outside of our solar system) in the habitable zone around a sun-like star, raising hopes that life may exist elsewhere in the galaxy. Space telescopes, such as TESS and JWST, are set to aid our ability in spotting these far-off worlds.
Biosignatures: Indicators of Life
Biosignatures: The Holy Grail of the extraterrestrial hunt. When we refer to detectable signs of life such as biosignatures, these include, but are not limited to, identifiers like organic molecules, distinctive gas mixes, or patterns that indicate life has affected the local and regional surroundings.
Methane detection in the Martian atmosphere, for example, has captured attention—because methane can be formed by both biological and geological means.
Refining the Search for Biosignatures
Astrobiologists are refining the search for biosignatures in all environments. At the Astrobiological Research Center in California, scientists are carrying out experiments to reproduce Martian conditions in order to verify if certain biosignatures can escape destruction or modification during their slow processes of degradation and alteration within Mars’ surface rocks.
Future Astrobiological Research Missions
A number of future astrobiological missions are poised to help answer questions regarding the existence of life elsewhere in the Universe.
NASA suggests bringing “Luna geoscience” to Mars: The US space agency needs payloads that can return discerning animal rocks from the Moon, researching them and sharing delivery for the Artemis program in step with a blog about shipping technology headed for the lunar vicinity.
Because of this potential, the Moon is seen as an excellent site to test out technologies and methods we will need for Mars.
Mars Sample Return Mission
Another sample will be returned to Earth in the late 2020s via the Mars Sample Return Mission, which aims to recover samples cached by Perseverance and deliver them to researchers on Earth. The mission could reveal new information about the planet’s past habitability and whether Mars has ever hosted life.
Philosophical and Ethical Issues of Interstellar Travel
The philosophical and ethical issues surrounding interstellar travel are highly complex but require further expansion in this review. Interstellar travel is another fascinating part of astrobiology as a whole.
Our current state-of-the-art technology constrains us to in-system exploration, but theoretical studies suggest that, maybe, one day, we’ll be able to reach other stars.
For instance, the Breakthrough Starshot venture plans to deploy microspacecraft to the closest star system (Alpha Centauri) using laser propulsion. The goal of this mission is to probe for habitable exoplanets in our nearest neighboring star system, Alpha Centauri.
Advancements in Propulsion Technology
Research is being carried out on propulsion technologies that could someday make space travel between star systems a possibility instead of just a theme in science fiction. Astrobiologists also, of course, agree that we will have to get on with it someday if we are to set out for the stars in any form.
The Role of Environmental Conditions
For example, knowledge about the environmental conditions on other planets and moons could be useful when it comes to astrobiology.
Temperature, pressure, radiation levels, and atmospheric composition are just some of the determinants that make an extraterrestrial body capable of harboring life.
For example, one of Jupiter’s moons—Europa—has a likely location of a subsurface ocean beneath the icy crusts on its surface which might harbor life.
Unique Targets for Astrobiological Studies
Similarly, Saturn’s largest moon Titan has bits of the air and oceans of fluid methane. These two exotic worlds occupy a unique position in the Solar System, providing compelling targets for astrobiological studies targeting life on other planets residing within inhospitable environments.
Encouraging Environmental Awareness
Given the continued search for alien life, it serves as a reminder of the need for environmental consciousness on our own planet.
Together with the fact that we know so little about how the many components of our own planet’s ecosystems interact, this makes it very challenging to determine what might be possible in terms of life on other planets.
Exploring the universe only stays useful if what we learn is done in a way that enables both our planet and ourselves to continue to exist.
The Call for Stewardship of Planetary Resources
As astrobiologists, we call for the careful management and stewardship of our own planetary resources, understanding that what we study in other worlds is also an education in how to assess planetary health and sustainability. Scientists are trying to develop ways of promoting responsible practices and conservation in hope of preserving both our Earth and potential otherworldly Eden.
The Future of Astrobiology
Yes, the future of astrobiology is incredibly promising, offering a new frontier of science to be carried out. As technology evolves and interdisciplinary scientist collaborations strengthen, the search for extraterrestrial life continues to become more interesting. The hunt for aliens speaks to our sense of adventure and innate desire to place ourselves in the wider context of what exists in nature.
A Global Culture of Discovery
Research and exploration are the areas that humanity invests in to create a global culture of discovery for our species. While the act of reaching for an understanding of life off our planet not only serves as mere inspiration, it also imparts us with a healthy dose of perspective: Life on Earth is special and sometimes too fragile to last.
Understanding Our Place in the Universe
Astrobiology has the possibility of providing answers to some of the most basic questions we have about our place in the Universe as humanity continues its journey to find out. The hunt for life elsewhere in the Universe tells us as much about our own hopes, dreams, and fears as it does about what else might exist.
