“Do extraterrestrials really exist?” “Are we not the only intelligent beings in the universe?” These are questions that are way older than most of us yet they are still left unanswered up to this day. Stargazers and scientists have dug deep into the possible existence of aliens since the past century, and they have found quite a number of unusual observations along the way.
As postulated by the Astrobiology Department of the National Aeronautics and Space Administration (NASA), “while no clear signs of life have ever been detected, the possibility of extraterrestrial biology — the scientific logic that supports it — has grown increasingly plausible. That is perhaps the single largest achievement of the burgeoning field of astrobiology, the broad-based study of the origins of life here and the search for life beyond Earth.”
Despite the difficulty of finding solid pieces of evidence for these claims about extraterrestrial life, astronomers are still resilient to look for answers by whatever scientific means possible. Here are some of the things you need to look into as we try to shed light on this alien conundrum.
- Life on Mars
Mars, also known as the Red Planet, is slightly like Earth and is believed to have been covered with water at some point in its primordial history. Stargazers claim to have had a glimpse of all manner of strange things on Mars, from fungi and pyramids to alien bears.
However, real scientists are never close enough to discovering whether Mars is nothing more than a dead planet, or whether it once supported life. It is widely thought that Mars has frozen over 3.8 billion years ago before the Medieval Warming Period (MWP) melted the surface and led to the creation of cavernous valleys and canyons. It is also believed that a huge build-up of greenhouse gases in the Red Planet’s dense atmosphere has caused dramatic climate cycles.
Hence, scientists have posited that this could be the reason why the planet has water-carved features. Water is a basic and necessary element for life — thus, there could have been living organisms on Mars billions of years ago, but were eventually wiped out due to extreme climate change.
- Dyson Spheres
Back in October 2015, scientists formed a new theory to find out why a distant star called KIC 8462852, or Tabby’s Star, was showcasing a bizarre “blinking” behavior that caused its light to dim occasionally.
One researcher claimed that the light was being blocked by a humungous object called a Dyson Sphere — a theoretical structure that could be built around a star for the purpose of harvesting its energy.
In 2019, Jason Wright of Penn State University said the strange signals around Tabby’s Star seemed to look like a “swarm of megastructures” and stated they were “something you would expect an alien civilization to build”.
“I can’t figure this thing out and that’s why it’s so interesting, so cool — it just doesn’t seem to make sense,” he told The Independent.
Aside from this Dyson Sphere theory, some other scientists have claimed the behavior of Tabby’s Star could be caused by a complex phenomenon called “avalanche statistics.”
- Ocean on Jupiter’s Moon
Some scientists uphold that Europa, which is about the size of Earth’s moon, has an ocean hidden beneath its icebound crust. If the predictions turn out to be legitimate, this could be a great place to look for extraterrestrial organisms.
“With abundant salt water, a rocky seafloor, and the energy and chemistry provided by tidal heating, Europa could be the best place in the solar system to look for present-day life beyond our home planet,” NASA said last year.
The said moon is thought to contain a huge global ocean containing twice as much water as Earth’s oceans lurking beneath a layer of intensely cold and hard ice of immeasurable thickness. NASA believes it has found evidence of water vapor plumes rupturing off the surface of Jupiter’s moon.
- Atmosphere in Saturn’s Moons
Same as Europa, Enceladus is an icy moon with a sublayer ocean of liquid water. It orbits the planet Saturn and has caught the attention of scientists as a potentially-habitable world following their discovery of its vast geysers near its south pole.
These streams of water came from large cracks on the surface and, considering Enceladus’ weak gravitational pull, splashed out into space. Apparently, they are proofs of an underground source of water.
Not only that, an array of organic molecules, as well as little grains of rocky silicate particles, were detected to be in physical contact with the rocky ocean floor for at least 90 degrees Celsius in temperature. This only proves the possible existence of hydrothermal vents on the ocean floor which provides the chemical balance needed for life and localized sources of energy.
Aside from Enceladus, Titan also shows great extraterrestrial potential. It holds a thick orange haze of composite organic molecules and a methane weather system in place of water. The atmosphere is composed mostly of nitrogen, a vital chemical element used in the formation of proteins in every known form of life. Radar observations have hinted the presence of lakes of liquid methane and ethane and possibly the presence of cryovolcanoes — volcano-like structures that emit liquid water rather than lava. This gives the clear idea that Titan, like Europa and Enceladus, has a sub-surface reservoir of liquid water.
Given its exceeding distance from the Sun, Titan’s surface temperature is at 180 degrees Celsius and is quite too cold for liquid water. However, the abundance of chemicals available on Titan has raised speculation that lifeforms — which could potentially be diverse from existing terrestrial beings — could dwell there.
Stargazers have peeked on a number of “exoplanets”, the name given to planets outside our own solar system. Since its launch in 2009, NASA’s Kepler Spacecraft has discovered more than 4,100 potential exoplanets.
From these figures, there have been 216 Earth-like planets positioned within the Goldilocks Zone — the region around a star in which the surface temperature of an orbiting planet might possibly support water.
However, whilst most of these Earth-like planets are habitable, they are thousands of light-years away, which means they are quite out of our reasonable reach.
Notwithstanding that, astronomers recently found a “second Earth” capable of supporting life. Astronomers at the European Southern Observatory (ESO) has spotted an alien world orbiting Proxima Centauri — a red dwarf, a small low-mass star about 4.25 light-years from the Sun, which they termed as Proxima b.
They also found a world orbiting a nearby star which is 14 light-years away, and it may have an atmosphere that can support life. European stargazers geared their telescopes on a planet called GJ 1132 b to uncover that it is blanketed by a thick atmosphere of “alien air.”
Once these dots are connected and solved, we may finally have evidence that aliens do exist — or, on one hand, get one step closer to concluding that humanity is the lone lifeform in the universe. To put it bluntly, we would not know whether extraterrestrials are indeed real until they get in touch with us or we find solid evidence of their existence. Moreover, even if we finally find a hint of extraterrestrial life, it might be in the form of other microorganisms, rather than full-grown intelligent beings.