Astrobiologists investigate exoplanets in order to detect evidence of life. Unfortunately, however, this approach misses many opportunities for discovery.
Life everywhere gathers information about its environment for survival and growth, using senses that may vary according to species.
Science fiction has long imagined humans terraforming alien worlds into habitable environments through a process known as terraforming. Now more than ever before, this idea seems plausible.
Origin
Scientifically speaking, extraterrestrial life refers to any life forms which originated outside Earth. Their existence remains uncertain at best as no conclusive examples have yet been identified.
Astronomers continue to search for evidence of extraterrestrial life, especially organic molecules that might contain clues to its existence – specifically DNA and RNA sequences that reveal clues as to its creation here on Earth.
Astronomers have started conducting sample-return missions in order to find similar signs elsewhere in the galaxy, which should provide scientists with all of the information needed to detect traces of extraterrestrial life formation in rocks.
Chemistry could provide further clues to these rocks’ origins; minerals in the Murchison meteorite have isotopic compositions which indicate they formed outside Earth rather than here, which is significant because such rocks contain essential building blocks for life.
Johnson worked on a project utilizing genetic sequencing technology to detect DNA and RNA from cosmic rock samples, providing her with insight into how astrobiologists could potentially utilize genetic methods to hunt for signs of alien life. It was fascinating but also made her curious as it caused her to consider what might happen if aliens didn’t use DNA/RNA but rather got their instructions through biochemical pathways instead.
Habitability
Habitability refers to a planet’s ability to support life. Although determining this can be challenging from simply its surface alone, it may be possible to detect biosignature signs if conditions permit.
Habitability can be defined by multiple criteria, including water availability and surface temperatures of planets, as well as their proximity to their host stars or presence of extraterrestrial objects like asteroids.
Liquid water availability is often used as the sole criterion to determine whether a planet is habitable. But other factors, including its location within its host star’s habitable zone and distance from other stars in its system as well as atmospheric composition and stellar activity (flares and superflares) could all play a part.
Scientists are searching for signs of life on other worlds, including chemical gradients or unexpected concentrations of molecules that might indicate life. Using cutting-edge models designed to comprehend planet environments and detect biosignatures of alien life forms, their research doesn’t rely on extraterrestrial life possessing specific biochemistry similar to ours – which may differ substantially – yet still look for certain markers such as power law distribution of cell sizes with an exponential decline as they get larger – which are known to indicate living organisms.
Evolution
Scientists have spent decades looking for signs of life on other planets – an endeavor known as astrobiology. While no proof exists for aliens’ existence, this field’s experts firmly believe aliens must exist somewhere out there and are open to thinking creatively about ways they might detect or even identify any such organisms that may exist out there.
Scientists have long predicted that complex organisms on other worlds would evolve similarly to those found here, yet also understand that conditions allowing major transitions such as switching from single-celled creatures into multicellular ones require very specific conditions – therefore experimenting with ways to simulate such environments in laboratory conditions.
Lynn Rothschild, an astrobiologist and synthetic biologist working for NASA’s Ames Research Center in Silicon Valley is one such researcher. In her lab, they are developing supersized extremophiles – organisms which thrive under extreme temperatures or conditions – in order to see whether they might work on other planets beyond Earth.
Other astrobiologists prefer the more general path of biosignature discovery to go the exoplanet route; their search focuses on chemical traces that indicate life without waiting for ET to return with an answer, such as carbon-based biochemistry which could indicate all life forms on an Earth-like world, and water or solvent signatures left by its presence.
Communication
Searching for extraterrestrial intelligence (SETI) involves scanning electromagnetic waves for radio transmissions that could represent alien civilizations; however, their chances of detection depend on how adeptly their observers can decipher information contained within our transmissions.
Communication experts often employ binary signals – which display information using on/off or present/absent logic – as the preferred mode. This design philosophy was predicated upon the assumption that any intelligent species would understand this form of encoding; yet even intelligent humans find difficulty deciphering this type of message, as evidenced by Frank Drake’s Arecibo message not being decoded properly by intelligent computer programs. Therefore, extraterrestrial species’ decipherment challenges will likely be much greater.
More sophisticated strategies for coding messages have been proposed, including pictorial systems such as Arecibo message and algorithms to deliver information. Writing systems discovered by archaeologists such as Linear A and natural language communication have also been put forth as potential solutions; numerous research projects are examining their feasibility.
One of the most remarkable developments is Lingua Cosmica, created specifically for ET communication. It combines symbolic logic, basic arithmetic and natural language into one system of communicating. Starting with simple facts like counting, its scope broadens out into complex subjects such as Pythagorean geometry wherein equal sides of two squares equal their hypotenuse.
