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Which planets in the universe have been destroyed?
The vastness and diversity of the universe is mind-boggling. From the tiny rocks orbiting a star to the supermassive black holes at the center of a galaxy, the cosmic landscape is dotted and shaped by countless celestial bodies. Some of them shine with dazzling beauty, others lurk in murky darkness, and still others have exploded or collapsed into oblivion. In this article, we will explore some of the planets that have met a tragic fate of destruction.
Before we dive into specific examples, let's clarify what we mean by “planet” and “destruction”. In general, a planet is a round or nearly round object that orbits a star and has cleared its orbit of other debris. According to the International Astronomical Union (IAU), there are currently eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto used to be considered a planet but was reclassified as a “dwarf planet” in 2006 due to its smaller size and uncertain status. However, other systems may have different criteria for what constitutes a planet, so we should keep an open mind.
As for destruction, there are several ways that a planet can be wiped out or severely altered. One of the most common causes is impact from another object, such as a meteoroid, asteroid, or comet. Depending on the size, speed, and composition of the impactor and the target, the collision can create a crater, eject material into space, or even trigger global disasters like earthquakes, tsunamis, and wildfires. Some impacts are so powerful that they can shatter a planet into fragments or vaporize it entirely, leaving only remnants or traces behind. Another way that a planet can be annihilated is through natural or artificial processes that alter its atmosphere, temperature, or magnetic field to the point where life or surface features become impossible. For example, a runaway greenhouse effect caused by too much carbon dioxide or water vapor could turn a habitable world into a hellish inferno, while a global cooling caused by a massive volcanic eruption or a nuclear winter could freeze it into a lifeless wasteland.
Now, let's take a closer look at some of the planets that have been destroyed, either in our solar system or beyond.
In our solar system, the most famous example of a destroyed planet is probably the one that no longer exists: the hypothetical planet between Mars and Jupiter known as the “missing planet” or the “fifth planet”. According to the leading theory of planetary formation, this planet should have formed like the rest of the solar system's planets, by accreting rocks and dust around a growing core. However, something happened that disrupted the process and shattered the planet into numerous fragments, which eventually became the asteroids that populate the main asteroid belt. Some scientists speculate that a giant impact, a close encounter with Jupiter, or a resonance with its gravitational pull may have triggered the breakup, but the exact cause remains a mystery.
Another example of a destroyed planet in our solar system is Venus, which has undergone a catastrophic evolution that made it one of the most hostile places in the solar system. While Venus is still technically a planet, its surface resembles a Hadean wasteland, with temperatures hot enough to melt lead, pressures strong enough to crush submarines, and an atmosphere thick with sulfuric acid clouds that block out most sunlight and reflect back heat. How did Venus become this way? The current theory is that it used to be more Earth-like, with oceans, continents, and a mild climate, but gradually lost its water and carbon dioxide to space due to a combination of solar winds, volcanic eruptions, and a runaway greenhouse effect. As the water vapor and carbon dioxide disappeared, the greenhouse effect intensified, raising the surface temperature to a point where all the remaining water boiled off, leaving behind a dry, hot, and hellish world.
Outside our solar system, there are several examples of planets that have been destroyed or distorted by various means. One of them is WASP-12b, a giant gas planet that orbits a star about 870 light-years away from us. This planet is so close to its star that it completes one orbit in less than a day, and its atmosphere is heated to a temperature of about 2,700 degrees Celsius, which is hotter than some stars. The intense heat has caused the planet to swell up and lose its outer layers, creating a bizarre shape that resembles a giant teardrop. The remaining core of the planet is about 3 times the mass of Jupiter, but it is doomed to spiral towards its star and eventually get engulfed by it in about 3 million years.
Another example of a destroyed planet outside our solar system is KIC 12557548b, a rocky planet that may have been obliterated by a catastrophic collision with another planet or a super-Earth. This planet was discovered in 2012 by the Kepler space telescope, which detected its transits in front of its host star. However, in 2015, a team of astronomers noticed that the light curve of the star showed irregular dips that could not be explained by the presence of the planet alone. After ruling out other possibilities, such as a binary star or a dust cloud, the team concluded that the most likely explanation was that the planet had been hit by another object and completely destroyed. The debris from the collision might have formed a dusty cloud that caused the observed dips, or it might have been ejected into space, leaving no trace.
In conclusion, the universe is a dynamic and unpredictable place, where planets can rise and fall in a cosmic blink of an eye. While some planets shine for billions of years and nurture life, others burn up, freeze over, or shatter into rubble. By studying the fate of these planets, we can gain a better understanding of the physical and chemical processes that shape the universe, as well as the fragility and resilience of life itself. Who knows what other surprises and tragedies the universe has in store for us? The adventure continues.
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