The search for extraterrestrial life has captivated human curiosity for centuries. However, it wasn't until 1995 that the discovery of the first exoplanet orbiting a star similar to our Sun sparked a rapid expansion in the field of astronomy dedicated to the study of these celestial bodies. Today, exoplanet exploration is one of the fastest-growing areas within the discipline. The most unusual exoplanets are those with unique characteristics and those located farther away.
In this article we are going to tell you which are the strangest exoplanets that exist and their characteristics.
What are exoplanets
NASA is heavily focused on the study of exoplanets, which are planets located outside our Solar System and are also known as extrasolar planets. Currently, more than four thousand exoplanets have been officially identified, each exhibiting unique characteristics that distinguish it from the others. To explore more about the different categories of exoplanets, you can visit our exoplanets section.
The European Space Agency (ESA) states that while some exoplanets are as large as Jupiter, they orbit much closer to their parent star than Mercury does to the Sun. Furthermore, some exoplanets are rocky, others icy, and some have no comparable equivalents in our solar system. This highlights the incredible diversity and unique characteristics of the strangest exoplanets in the universe.
Conversely, there are systems that support multiple planets, in which these planets orbit two stars simultaneously, and a select few of these planets possess the potential to sustain stable water on their surfaces—a crucial component for life as we know it. For more information about water on other planets, see our article on water on other planets and moons.
How are they detected?
The exploration and identification of extrasolar planets can be achieved through various approaches. One such technique involves studying the behavior of stars, known as the wobble star method. This method suggests that when a star has planets orbiting it, the gravitational pull causes the star to deviate from its regular orbit, resulting in a noticeable wobble . While this method allows for the detection of additional planets by observing the star's motion, it is somewhat subjective, as the ease or difficulty of observing these wobbles depends on the size of the planet.
In the case of exoplanets similar in size to Jupiter, it's easy to observe that the star experiences specific movements corresponding to the planet's orbit. In contrast, detecting the subtle oscillations of the star is a challenge when dealing with exoplanets of similar dimensions to Earth. If you'd like to learn more about Jupiter, you can consult our article on Jupiter.
Another approach, known as transit, involves the empirical observation of a specific phenomenon. A transit occurs when a planet crosses in front of its star, causing a slight decrease in the star's brightness as the planet partially obscures its light. This transit method is essential for understanding the characteristics of planets.
By closely monitoring the fluctuation in a star's luminosity during a transit, astronauts gain valuable information about the planet's size and its proximity to the star. This knowledge plays a fundamental role in the search for extraterrestrial life, as it provides crucial data about the planet's habitable zone, where conditions such as temperature and the possible existence of liquid water, a vital component for life, can be determined.
The strangest exoplanets
NASA launched a spacecraft called Kepler in 2009 to explore exoplanets. Kepler diligently searched for planets with diverse characteristics, such as different sizes and orbital patterns, orbiting stars of varying magnitudes and temperatures. While the spacecraft has successfully detected thousands of exoplanets, a subset of these celestial bodies continues to captivate scientists with their enigmatic nature. A visit to NASA's website dedicated exclusively to observing exoplanets discovered by Kepler will offer a glimpse into these fascinating discoveries.
Kepler 36B and 36C
Within the same star system, Kepler-36, there exists a fascinating pair of exoplanets that differ greatly from one another. Despite their disparities, both planets orbit very close to their host star. What makes this arrangement intriguing is the fact that , while Kepler-36B, a planet 1,5 times the size of Earth, completes an orbit in just 14 days, Kepler-36C is a scorching Neptune with a mass eight times that of Earth and a diameter 3,7 times that of our own planet.
The unique nature of these two planets lies not only in their contrasting sizes, but also in their distinct compositions: one is a solid rocky planet and the other resembles an ice giant similar to Neptune. This combination, along with their positions relative to each other, presents an intriguing case study. While planet 36B experiences intense tidal forces that are likely to result in periodic volcanic activity, Kepler planet 36C occupies a completely different location with its own distinctive temperature. That's why NASA's renderings of the conjunction between these two exoplanets every 97 days are so visually stunning and inspiring.
Kepler 16B
The first exoplanet ever detected orbiting a binary star system, consisting of an orange dwarf and a red dwarf, has been identified. It is one of the strangest exoplanets in existence. Located 200 light-years away, this exoplanet is roughly the same size as Saturn. NASA scientists have estimated that its surface temperature ranges from -73° to -101° Celsius due to the relatively smaller and less intense nature of its twin stars compared to Earth.
Interestingly, this exoplanet was detected by Kepler as it transited in front of its binary stars, evoking thoughts of the iconic Tatooine scene from the Star Wars saga, where two suns can be seen at sunset. Furthermore, its discovery contributes to our understanding of star formation.
Kepler 452B
Kepler 452b undoubtedly stands out as the exoplanet that prompts reflection on the possible presence of intelligent life beyond our own world. This celestial body, announced on July 23, 2015, is similar in size to Earth and has a hospitable environment.
The "Earth's cousin" designation has been given to an exoplanet known as Kepler 452, which orbits a Sun-like star and lies within the habitable zone. This particular celestial body is just one of the numerous exoplanets documented by NASA. Each of these exoplanets possesses unique attributes and offers a multitude of intriguing options for exploration. To delve deeper into the enigmatic world of these planetary bodies, you can visit the website of the esteemed National Aeronautics and Space Administration of the United States.
I hope that with this information you can learn more about the strangest exoplanets and their characteristics.