Top 10 Mysterious Planets That Baffle Astronomers

Top 10 Mysterious Planets That Baffle Astronomers

Introduction

The space has for a long time been a mystery to humankind. While much may have been learned about our immediate solar system, the discovery of exoplanets, so-called worlds orbiting other stars, ushers in even more overarching mysteries. Some of them would change our current understanding of just how stars and planets form and evolve, while others still raise a question of whether or not alien life exists. These 10 mysterious planets represent some of the strangest and most intriguing worlds ever discovered, each raising more questions than answers.
10. Kepler-78b: The Hellish Twin of Earth

Kepler-78b is an exoplanet that astronomers initially thought could be a rocky twin of Earth. It is almost identical to our planet in size and density and orbits a star roughly 400 light-years away. That's where the similarities end.

Kepler-78b is close enough to its parent star that it completes a full orbit in a meager 8.5 hours, which slings its surface temperature to over 2,000°C-hot enough to vaporize most metals. But as scorching as Kepler-78b may be, the real enigma is how this world came to be. As far as any theories of planetary formation are concerned, no planet should be able to form or survive at such proximity to its star.

Even more mysterious is its fate: Kepler-78b is slowly spiraling toward its host star and is expected to meet its demise a few million years from now. Despite that doom, it has given scientists much-needed lessons in the conditions that exoplanets can take.

9. WASP-12b: The Planet Being Eaten Alive

The object, WASP-12b, is located about 1,400 light-years from Earth. This gas giant, named a "hot Jupiter," goes around its host star in about one day-long orbit. Consequentially, the proximity is causing the host star to distort gravitationally with the planet due to its excessive attraction-which is basically tearing it to shreds-so it had been tagged also as "doomed" by astronomers:

What makes WASP-12b even stranger is its albedo-or lack thereof. The planet absorbs just about all the light it gets, making it one of the darkest planets ever discovered. Scientists believe that its atmosphere is full of complex chemicals, including vaporized metals, which serve to absorb light rather than reflect it.

As the star continues to strip its outer layers off the planet, WASP-12b's atmosphere forms a glowing trail of gas, reminiscent of a comet's tail. Eventually, in time, it will be fully engulfed by its star. This provides astronomers with a rarely seen glimpse into the life cycle of gas giants and their interactions with their host stars.

8. Gliese 581c: The Possible Second Earth

When Gliese 581c was discovered in 2007, it was hailed as one of the most promising candidates for habitability outside our solar system. Located just 20 light-years away, this rocky planet lies within the habitable zone of its star, where temperatures could allow liquid water to exist.

But since then, further research has called that into question; it's now thought that carbon dioxide could dominate the atmosphere of the exoplanet, with a runaway greenhouse effect somewhat like that which affects Venus. If so, the surface is probably far too hot for life to exist.

Adding to the intrigue, Gliese 581c's parent star is a red dwarf-a class of star prone to frequent solar flares that could strip the planet's atmosphere over time, leaving it barren. Despite these challenges, Gliese 581c remains one of the most intriguing targets for future exploration and a symbol in the search for Earth-like worlds.

7. HD 209458b: The Planet with Disappearing Atmosphere

Nicknamed “Osiris,” HD 209458b is a gas giant that’s slowly losing its atmosphere to space. Located 150 light-years away, it was one of the first exoplanets discovered with a leaking atmosphere. This phenomenon occurs because the planet orbits extremely close to its star, causing its outer layers to be heated and stripped away by stellar winds.

What makes HD 209458b special, though, is the level of detail astronomers have managed to glean about its atmosphere. The observations have turned up signs of hydrogen, carbon, and even oxygen streaming out into space. This has helped scientists learn how atmospheres behave under such extreme conditions, offering clues about the evolution of planets in hostile environments.

Despite its hostile conditions, HD 209458b has turned out to be a treasure chest of data that has helped astronomers fine-tune methods for probing the atmospheres of extrasolar planets.

6. Kepler-22b: A World in the Habitable Zone

Kepler-22b was the first planet to be discovered through the habitable zone of a star much like our Sun. This planet, 600 light-years away, is about 2.4 times Earth's size and thus falls under the category called "super-Earths.

What really makes Kepler-22b so mysterious is its composition: it is unsure whether it is a rocky planet, a gas giant, or an ocean world completely covered by water. If it's an ocean world, it might host alien life beneath its surface.

Adding to the intrigue, Kepler-22b's star is extremely stable-a factor that could support life. But much about this enigmatic world is left to speculation as there is not enough data.

5. 55 Cancri e: The Diamond Planet

Imagine a diamond-rich world; that is what 55 Cancri e promises, lying 40 light-years away from Earth in the direction of the constellation Cancer. 55 Cancri e is called a super-Earth because it measures twice the size of Earth and has a mass eight times as heavy. Such extreme composition develops from its high carbon content with intense pressure. Astronomers theorize that its surface could be rich in graphite and diamond, one of the most eccentric worlds ever discovered.

But 55 Cancri e is anything but luxurious: it orbits its parent star so tightly that surface temperatures reach as high as 2,400°C. The resulting extreme heat would mean the planet's surface would be covered in flowing lava, hostile to life as we know it.

Even more interesting, though, is its "day-night cycle." Due to one side constantly facing its star, day is permanent on that side, while the other side is in complete darkness. This huge difference in temperature adds another layer of mystery, which makes 55 Cancri e one of the most studied planets in its category.

4. TrES-2b: The Darkest Planet Ever Found

TrES-2b is no ordinary gas giant. At about 750 light-years from Earth, it is considered the darkest planet ever found. This "hot Jupiter" reflects less than 1% of the light that reaches it and is thus darker than coal.

Scientists believe that the atmosphere of TrES-2b contains certain light-absorbing chemicals, such as vaporized sodium, potassium, and titanium oxide. These chemicals trap light instead of reflecting it, giving the planet its eerie black appearance.

Despite the gloom, it emits a dim red glow at a temperature above 1,800°C. This is because the heat emanates from the interior, in continuous bombardment with energy from its star.

The mystery properties of TrES-2b raise many questions about how such planets can form and why they all have unique atmospheric compositions. Its discovery has sparked interest in studying similar dark exoplanets across the galaxy.

3. Rogue Planets: Drifters Without Stars

Most mysterious objects that populate the galaxy are rogue planets. While many planets orbit their stars, some just wander aimlessly in space. Such gravitational ejections emanate from initial star systems following gravitational interactions that are expected.

What makes rogue planets so intriguing is the possible harboring of life on them. Some scientists theorize that rogue planets could retain heat from their formation or have thick atmospheres that trap geothermal energy, thus allowing subsurface oceans to be present. These may host microbial life shielded by layers of ice.

Detection of such rogue planets is highly difficult as they neither emit light nor reflect enough to get spotted by telescopes. However, with recent technological advancement, a few such wanderers were identified by astronomers, which hinted at the huge population of rogue planets present in the Milky Way.

2. GJ 1214b: The Water World

Because of its unique composition, GJ 1214b is often referred to as a "water world." This super-Earth, located 40 light-years away from Earth, is believed to be covered with complete water and a thick atmosphere filled with steam.

Mystery ensues because of GJ 1214b's most signature attribute-water. Scientists say the high pressure and temperature within the planet might be able to create states of water that are unknown on Earth: "hot ice" or even "superfluid water.".

The planet’s thick atmosphere also raises questions. It’s unclear what gases make up its air, but studies suggest it could contain hydrogen, helium, and water vapor. If life exists on GJ 1214b, it would need to adapt to an environment completely unlike anything we’ve seen before.

1. Proxima b: Earth’s Mysterious Neighbor

Proxima b is probably the most interesting exoplanet to date. Orbiting Proxima Centauri, the closest star to our solar system, this rocky planet actually lies in the habitable zone of its star. It's 4.2 light-years from Earth-the nearest exoplanet from us that might support life.

There are, however, some significant challenges for Proxima b. Its parent star is a red dwarf star that has powerful solar flares which could, over time, strip away the planet's atmosphere. If Proxima b had a magnetic field strong enough to protect it, it might still support liquid water on its surface.

Adding to the mystery, the ground details of Proxima b are yet to be known by scientists. It could be a desolate, abysmal desert; a lush, vibrant world teeming with life; or maybe something totally unexpected. Proxima b is one of the best chances humanity has to find alien life, and future missions could reveal its secrets.