Buzz
The question of whether aliens exist has intrigued both scientists and ordinary people for many years. From Spielberg's classic E.T. the Extra-Terrestrial to NASA's recent announcements, the topic has always been a major point of interest. In fact, many people do believe that extraterrestrial life exists in some form.
For life to thrive, it requires water and an energy source. Naturally, there are planets, exoplanets, and moons that meet these essential conditions. While we may not come across little green men with large eyes, the possibility of finding life remains an exciting prospect. Here are the top 10 locations where we have the best chance of discovering life in the universe.
10. TRAPPIST-1
TRAPPIST-1 is a planetary system located just a few dozen light-years away, with its discovery being announced in early 2017. This system consists of seven Earth-like exoplanets orbiting a star classified as 'ultra-cool', making it one of the top candidates for finding life beyond our solar system.
Studying these exoplanets will be relatively straightforward due to their unique orbital patterns. We can observe their transits, which occur when they pass in front of their star from our viewpoint, causing a brief dimming of the star’s light as the exoplanet crosses between the star and Earth.
The exoplanets in this system maintain favorable temperatures thanks to the type of star they orbit. This means the conditions are just right for liquid water to potentially exist.
While all the exoplanets in this system are solid contenders for supporting alien life, three of them are positioned within what is known as the habitable zone. This zone surrounds a star, and within it, an Earth-like exoplanet can maintain liquid water—crucial for life forms, like those on Earth, that require water to survive.
9. Titan
Titan, the largest moon of Saturn, the sixth planet from the Sun, could potentially support life, though not in the way we imagine. It doesn't fall within the traditional habitable zone we typically expect.
Titan does have water, though not in liquid form. The water on this moon is completely frozen due to the extremely low temperatures.
Instead of water, the lakes and rivers on Titan are filled with hydrocarbons. These compounds consist of hydrogen and carbon in various combinations, and on Earth, we commonly encounter them as gases like methane or propane.
This key element would make potential life on Titan drastically different. In essence, life forms there would not thrive on liquid water like we do, but instead on liquid hydrocarbons.
While there are still some scientific questions and uncertainties (such as whether life could survive without water), the possibility of alien life on Titan remains very real.
8. Europa
Europa, one of Jupiter’s moons, is another prime candidate in our own solar system due to its potential for holding liquid water. It's believed to have everything necessary for life: water, energy sources, and the right chemical makeup. The water is thought to be stored in vast oceans beneath Europa’s icy surface.
It wasn’t until recently that scientists enabled the possibility of exploring life on this moon. In early 2017, a mission named Europa Clipper was announced, set to take place over the following years. This mission involves sending a spacecraft to Jupiter’s moon to capture images of its surface. The flyby will occur multiple times, providing various chances to study the moon and search for signs of life.
7. Mars
The Red Planet, the fourth from the Sun, is arguably one of the most discussed potential sites for alien life and even human colonization. Despite skepticism, the possibility of extraterrestrial life on Mars is a real and serious consideration.
It’s clear by now that we won’t find little green men or any form of intelligent life as we know it. However, there is compelling evidence that microbial life may have existed and could still exist on the small red planet.
Data from NASA suggests that floods and streams once flowed across Mars’s dry surface, indicating that liquid water might have existed there. This opens the possibility that life could have survived. With more exploration, scientists could uncover current liquid water on Mars, beyond just the ice caps we see today.
6. Enceladus
Enceladus, one of Saturn’s moons, has generated considerable excitement in the astronomical community due to its potential to harbor water, unlike its hydrocarbon-rich counterpart. The water is believed to exist beneath the moon's icy crust, much like Europa.
This once again suggests that microbial life may exist there. Initially, the presence of water was just a hypothesis based on evidence discovered in 2015, which gave scientists renewed hope.
In early 2017, a mission involving the Cassini spacecraft detected hydrogen molecules, indicating a chemical reaction happening beneath the surface. This reaction, where ocean water interacts with surrounding rock to generate energy, could provide a crucial energy source for life, as energy is vital for life forms as we know them.
5. Kepler-186f
Kepler-186f is an exoplanet that orbits the star Kepler-186, located about 500 light-years from Earth. Discovered in 2014, it became the first Earth-sized exoplanet found within its star’s habitable zone.
At just slightly less than 10 percent larger than Earth, it is considered our closest “match” in terms of size. While its density remains unknown, the exoplanet's size suggests it could have a rocky composition.
Kepler-186f’s Earth-like size and its position in the habitable zone are key factors that make it a strong contender for supporting life. However, the existence of water remains unconfirmed due to the lack of crucial details, such as temperature information.
Since Earth is the only known planet that hosts life, the idea is that a planet similar to Earth in other ways might also harbor some form of life as we understand it.
4. Kepler-452b
NASA suggests that Kepler-452b could be “one of the best [places] to find extraterrestrial life.” However, exploring this exoplanet may be challenging due to its distance—over 1,000 light-years away. Still, scientists have confirmed that Kepler-452b resides within its star’s habitable zone, accompanied by several other exoplanets.
For a time, Kepler-452b held the title of being the closest in size to Earth, though that distinction now belongs to Kepler-186f. Nevertheless, Kepler-452b’s star is much more similar to our Sun, which adds to its intrigue. Additionally, this exoplanet remains a focal point of research, especially for the SETI (Search for Extraterrestrial Intelligence) Institute, a leading organization in the search for extraterrestrial life.
3. Ganymede
Another one of Jupiter’s moons, Ganymede, might also harbor life. Like its fellow moons, Ganymede is believed to have an ocean beneath its icy surface. In fact, this ocean could hold more water than all of Earth’s oceans combined. Research on Ganymede’s surface even suggests that a flood may have occurred in the past, possibly when liquid water seeped out through cracks or other openings.
The study of this moon has led to innovative research techniques. For instance, by examining magnetic fields, scientists may be able to learn more about the moon’s interior, including the potential presence of liquid water beneath the surface.
As of early 2017, no specific mission is focused on Ganymede, but a probe named JUICE (JUpiter ICy moons Explorer) is set to explore Jupiter’s moons in greater detail over the next few years.
2. Tabby’s Star
Tabby’s Star, also known as KIC 8462852, has sparked quite a bit of excitement due to its mysterious behavior, which some believe could be linked to an 'alien megastructure.' Well, maybe.
Located 1,500 light-years from Earth, Tabby’s Star was discovered by Yale astronomer Tabetha Boyajian. It stands out for its strange dimming patterns, which are too extreme to be caused by a planet passing in front of it. Other theories include the possibility of an unknown space object or, more intriguingly, the presence of aliens.
An alien megastructure would be an enormous structure designed to capture energy from a star and transform it into a more useful form. When a star loses energy, it dims, so the concept of an alien megastructure seems plausible, at least to some extent.
One of the most recent and plausible theories surrounding Tabby’s Star is that it consumed one of its own planets, which is quite a captivating thought in itself. However, the possibility of aliens still hasn't been entirely dismissed.
1. LHS 1140b
LHS 1140b, a newly discovered exoplanet, lies within its star's habitable zone. Many scientists consider this 'super-Earth' one of the best candidates for discovering other forms of life beyond our planet.
A super-Earth refers to an exoplanet that is up to ten times more massive than Earth. These planets are often thought to be rocky, although this can’t be confirmed without further study. LHS 1140b, considered the ultimate super-Earth, is believed to have a rocky composition with an iron core… and might even be home to alien life.
Located just 40 light-years away, this exoplanet is ideally positioned for us to potentially send a signal to any intelligent life that may reside there. Moreover, LHS 1140b's slower rotation makes it easier for scientists to observe and study from Earth.
