Exoplanet TrEs-2b: “The Dark Knight”
Welcome to the planet that is darker than the darkest black on Earth.
Known as “The Dark Knight,” exoplanet TrEs-2b is the darkest planet ever observed orbiting a star. It is 702 light-years from Earth.
This darkness arises from the fact that it reflects only 1% of the light received by its star. Since the planet is so dark, you would think it would be a very cold place. But the opposite is true. The average temperature is 1,800°F—as hot as lava. TrEs-2b’s atmosphere literally burns. Because of this, a few scientists do believe that the planet would emit an ominous, deep red glow.
TrEs-2b is a gas giant, which means it is heavily intoxicated with gasses. It’s gained the nickname “Hot Jupiter.” Compared to this planet, Jupiter is freezing. TrEs-2b is nearly half the size of Jupiter, and shares similar elements like titanium oxide, sodium, and potassium. For a planet so similar, you would expect ammonia clouds—but even this planet is too hot to form those clouds.
If this planet is so dark, then how did astronomers spot it? Well, they didn’t directly. Astronomers found TrEs-2b through a method called “transit.” It’s basically searching for shadows. When a planet passes directly between the telescope and the star it orbits, it blocks some of that star’s light. This tiny change is sometimes enough for astronomers to predict the existence of an exoplanet. 3,854 planets have been discovered through transit, making it the most common method for discovering exoplanets.
Note: A light year is a measure of distance. One light year is how far light can travel in a year. This is 5,878,625,370,000 miles. If we hopped onto a space shuttle and blasted into space at maximum speed, it would take 37,200 human years to travel just one light year. That’s a heck of a long time.