Life beyond Earth has been a topic in most people’s conversations for centuries, and it’s fascinating to think that there could be a higher form of life out there somewhere in the multiverse.
However, while the multiverse may be hypothetical and is undoubtedly a vast subject to delve into entirely for newbies and space enthusiasts alike, the distant dream of life forms outside of Earth is kept afloat with the existence of Exoplanets.
If you’re here, then you might have an idea of what Exoplanets are.
And even if you have stumbled on this article by chance, stick around cause we’ll be sure to tickle your curiosity with these strange new worlds that have been found. And how they bring the possibility of extraterrestrial beings living in the unknown!
But first, let’s start with the basics!
What Exactly Are Exoplanets?
In simplest terms, Exoplanets, or Extrasolar planets, are any planets that exist apart from our own solar system. These planets usually orbit around stars, like the Earth and the Sun, and most scientists believe each star can have one exoplanet.
On the other hand, some Exoplanets float in space without orbiting around a star, but in the galactic center, these Exoplanets are categorized as rogue planets.
While the first-ever exoplanet was discovered around the 1990s, further into today, a total of more than 5000 Exoplanets have been discovered by scientists, and believe it or not, that is just the tip of the iceberg.
As we’ve mentioned, there is a possibility that each star has one exoplanet orbiting around it; even our galaxy has around 100 billion stars; imagine the Exoplanets that exist in our Universe, which hosts at least over 100 billion galaxies.
However, there are only a little over 5000 Exoplanets discovered today since most of these Exoplanets are located trillions of miles away, the closest being four light years, and like Earth, they reflect the light of their sun.
So naturally, the Exoplanets are hidden by the outshining light of various stars, even in our galaxy, making it extremely difficult to detect them with our current technologies.
These Exoplanets are made up of similar elements to the planets in our solar system but may differ in the mix of these elements. Some Exoplanets may be filled with ice or water, while some are filled with carbon or iron.
Accordingly, these Exoplanets may be rocky like Venus or Earth or rich in gas like some of the planets in our solar system.
What Are The Types Of Exoplanets?
As we’ve mentioned, out of the thousands of Exoplanets discovered to date, scientists have figured out that the planets vary greatly depending on their composition and the exterior and interior appearance they hold!
Here are the types of Exoplanets you should know about.
The Terrestrial Exoplanets
These Exoplanets are generally the size of the Earth or smaller and way miniature compared to most of the planets discovered. They are usually composed of carbon, water, rocks, or silicate.
With the advancement of technologies, scientists are tirelessly investigating if some of these terrestrial Exoplanets, like the Trappist-1 e, are equipped with habitable atmospheres or oceans but are not limited to this.
These Exoplanets are commonly known as terrestrial, yet differentiating them from other terrestrial Exoplanets is that they are more massive and even exceptionally larger than Earth.
However, while Super-Earths may be twice as big as the Earth, they are light compared to giants like Uranus or Neptune, and in addition, they may be composed of gas, rocks, or both.
Clouds of uncertainty reign above these Exoplanets with possible habitable conditions. Hence scientists are trying to uncover the mystery behind them since even though these types of planets are non-existent in our solar system, they resemble some of our planets.
An example would be Kepler-186f which has the potential to turn out to be a rocky planet similar to Earth but exceptionally bigger.
The Neptunian Exoplanets
These Exoplanets are called the Neptunians since they are similar in size to our very own Uranus and Neptune. While the inner composition of Neptunians may differ, they are all commonly dominated by helium and hydrogen atmospheres paired with cores consisting of heavy metals or rocks.
This uncertainty about the composition of the elements on these Neptunian Exoplanets is due to their super heavy clouds that block light from going through them. This makes it hard for scientists to decipher the molecules present in their atmosphere.
The Gas Giants/Exoplanets
Some of the largest Exoplanets that have been discovered are categorized as gas giants since they come head-to-head in size with the largest planet in our solar system, Jupiter, but they can even be much bigger.
These Exoplanets are composed of hydrogen and/or helium, and much like our Jupiter, they don’t contain hard surfaces but rather have gases swirling above a solid planetary core.
Gas giant Exoplanets are also much closer to their stars, so their temperatures take off and are always in the thousands of degrees regardless of whether it’s in Celsius or Fahrenheit.
In recent times, even though we are not fully equipped with the best technologies to spot Exoplanets that are further than some trillion miles away, the possibility is endless, and we have so much time in our hands.
Navigating and studying these planets helps us learn the mysteries behind our Universe and how everything works in the dark unknown we call today as space.
But perhaps, the most compelling reason why we study Exoplanets might be, indeed, with the hope of discovering sentient beings living among us, far away from what we call home.
Moons are enchanting, and why they may not be, as these celestial bodies have always fascinated humans, especially the scientific community.
Our Earth has one, and even 50 years after landing the first man on the moon, scientists still have a thousand questions about our moon yet to be answered (the dark side particularly).
So what about the moons revolving around other planets in our solar system? Do they intrigue the scientific community too?
Yes, they do, and today we will get to know about Jupiter’s fascinating moons that have been baffling scientists for decades.
Excited? Get on board.
How Many Moons Does Jupiter Have?
According to NASA, Jupiter has 80 moons, out of which 57 have official names given by the IAU or the International Astronomical Union.
These celestial bodies combine to create a satellite system, called the Jovian system. However, scientists are monitoring the planet closely, and we can expect more moons around this gas giant.
Although Jupiter has several unique moons, scientists are especially intrigued by the four giants (Galilean satellites), namely Ganymede, Io, Callisto, and Europa.
Why? These moons are massive, and scientists would have considered them planets if they orbited around our sun. Simon Marius and Galileo Galilei were the first astronomers to discover them in 1610.
Let us learn more about these massive Jupiter moons.
- Ganymede – The Largest Moon
Ganymede holds the record of being the largest moon present in our solar system. In fact, Ganymede is so massive that it has an independent magnetic field with regions where you can experience northern lights.
Besides having a magnetic field, scientists have also found evidence of oxygen in Ganymede’s atmosphere. However, the oxygen layer is fragile and may not support life.
Ganymede has several terrains that appear after faulting or water release. There are also dark terrains on this moon that may indicate or depict the moon’s crust. Furthermore, these dark regions have multiple craters covered with ice.
Ganymede has a crisscrossed surface that features a collection of new and older terrain. This unique surface structure gives Ganymede its distinctive look and makes it stand out from the rest of the cluster.
- Callisto – The Ugly Duckling
Callisto is the 2nd largest moon of Jupiter and has the most craters in the entire solar system. This heavily cratered look helped it bag the title ‘ugly duckling’ in the scientific community.
However, there is more than meets the eye, as studies suggest that Callisto may have a salty ocean beneath its surface. In short, there can be life beneath the icy crust of this massive moon, which is why scientists keep a constant eye on this Jupiter moon.
So how wide is the salty ocean? According to estimates, Callisto may be hiding in a massive ocean below its icy surface. Furthermore, studies also indicate that the ocean may reside around 250 kilometers or 155 miles beneath the surface.
Other estimates also suggest that Callisto may have metal and rock mixed with ice, which translates the possibility of supporting living organisms in the salty ocean.
If these estimates come true, we can expect a fleet of controlled satellites heading toward Callisto soon.
- Io – EYE oh
Besides having ice-dominated moons, Jupiter also has a moon with the most volcanic activity in our solar system. Meet the third largest moon of Jupiter, Io, featuring a combination of three different celestial bodies in one.
Io or ‘EYE oh’ is similar to our Earth’s moon and shares a significant similarity. Io orbits Jupiter tidally, meaning Io only faces Jupiter from one side during its orbit.
However, Io has an elliptical orbit, which is the primary reason Io experiences many volcanic activities. The tidal force of the planet puts enormous gravitational effects on Io, causing its surface to erupt throughout its orbit.
In short, there are hundreds of lava fountains and volcanoes that are active on Io that can shoot lava miles high from the surface. You can compare this gravitational pull with Earth’s moon as both run on identical principles.
However, our moon’s gravitational effect is significantly less than Jupiter’s Io and does not harm our planet.
Besides volcanic activity, Io also alters Jupiter’s atmosphere and causes lightning storms in the upper atmosphere. This phenomenon is often experienced when Io is above Jupiter’s magnetic field, transforming the moon into a generator generating electricity.
So is life possible on Io? Although life can thrive in most inhospitable places, scientists believe that the extremity of Io’s atmosphere is not ideal for supporting life.
Europa is a fascinating moon in the cluster of Jupiter’s moons, as it may have a watery ocean beneath the icy crust. Scientists had their fascination growing after the Voyager craft provided clues that a massive ocean might be hiding below the surface.
Furthermore, Europa’s icy crust is not as thick as other moons and may have an ocean up to 100 miles deep. If these calculations and estimates are accurate, Europa may be holding more water than Earth, which will undoubtedly allow life to prosper on the moon.
However, Europa is 5.2 AU (Astronomical Units) away from the sun, meaning that the sun’s energy is probably against the odds. So without a significant energy source, life on this celestial body can be a bit challenging.
On the other hand, the Galileo craft witnessed convection on the moon’s surface, including domes and pits. In short, some heat sources can be beneath the surface, which may help life to exist on Europa.
Although humans have a long way to go before we can set foot on this possible exoplanet, we can collect water samples from space and determine whether alien life exists on the moon.
NASA is planning a crucial mission to this moon called the Europa Clipper to conduct a detailed survey of this possible exoplanet.
Jupiter’s moons have different characteristics and have been intriguing researchers for decades.
Thankfully, modern techniques and advanced equipment have helped the scientific community to understand these moons better, and soon we may have operated spacecraft heading that way.