Strangest planets that exist But You don't know of

1. The Three Sun Planet

Imagine this: a planet with either constant daylight or triple sunrises and sunsets each day depending on the seasons (which last longer than human lifetimes).

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date. With a temperature of 850 kelvins (about 1,070 F or 580 C) and weighing in at an estimated four Jupiter masses, it is also one of the coldest and least massive directly-imaged exoplanets.

2. Earth-Like Planet 

Also known as COROT- 7B A new study of the planet, which orbits a star 500 light years away, has shown that its density is similar to Earth's, indicating it is a solid rocky world. It is the first planet to be discovered beyond our Solar System with a solid structure that could support living organisms.

However, because COROT-7b is only 1.6 million miles from its parent star, 23 times closer than Mercury is to the Sun, it is too hot to harbour extraterrestrial life.

Although COROT-7b's mass remains uncertain, with a range between 2 and 8 Earth masses, its radius and orbital period are well known from COROT photometry: it orbits very close to its star (1/23rd the distance from the Sun to Mercury) with an orbital period of 20 hours, 29 minutes, and 9.7 seconds and has a radius of 1.58 Earth radii. COROT-7b has the shortest orbit of any planet known at the time of its discovery.

COROT-7b has a maximum surface temperature between 1800 and 2600 °C (3300 to 4700 degrees Fahrenheit). Due to the high temperature, it may be covered in lava.

3. The Dark Planet 

It may be hard to imagine a planet blacker than coal, but that's what astronomers say they've discovered in our home galaxy with NASA's Kepler space telescope An alien world blacker than coal, the darkest planet known, has been discovered in the galaxy. Orbiting only about three million miles out from its star, the Jupiter-size gas giant planet, dubbed TrES-2b, is heated to 1,800 degrees Fahrenheit (980 degrees Celsius). Yet the apparently inky world appears to reflect almost none of the starlight that shines on it, according to a new study

4. The Diamond Planet 

Research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. The study estimates that at least a third of the planet’s mass – the equivalent of about three Earth masses – could be diamond.

55 Cancri  is an exoplanet in the orbit of its Sun-like host star 55 Cancri A. The mass of the exoplanet is about 8.63 Earth masses and its diameter is about twice that of the Earth, thus classifying it as the first super-Earth discovered around a main sequence star, predating Gliese 876 d by a year. It takes less than 18 hours to complete an orbit and is the innermost known planet in its planetary system. 55 Cancri e was discovered on 30 August 2004. However, until the 2010 observations and recalculations, this planet had been thought to take about 2.8 days to orbit the star.^[2] In October 2012, it was announced that 55 Cancri e could be a carbon planet

5. Methuselah Planet  

PSR B1620-26 b is an extrasolar planet located approximately 12,400 light-years away from Earth in the constellation of Scorpius. It bears the unofficial nicknames "Methuselah" and "the Genesis planet" due to its extreme age and a few popular sources refer to this object as "PSR B1620-26 c" The planet is in a circumbinary orbit around the two stars of PSR B1620-26 (which are a pulsar (PSR B1620-26 A) and a white dwarf (WD B1620-26)) and is the first circumbinary planet ever confirmed. It is also the first planet found in a globular cluster. The planet is one of the oldest known extrasolar planets, believed to be about 12.7 billion years old.

6. Planet Nine

Planet Nine is hypothesized to follow a highly elliptical orbit around the Sun lasting 10,000–20,000 years.The planet's semi-major axis is estimated to be 700 AU,^[B]roughly 20 times the distance from Neptune to the Sun, and its inclination to be about 30°±10°^[C] The high eccentricity of Planet Nine's orbit could bring it as close as 200 AU at its perihelion and take it as far away as 1,200 AU at its aphelion.

7. Starless planet 

PSO J318.5 is a rogue planet, an extrasolar object of planerary mass that does not appear to have a host star. It is approximately 80 light-years away, and belong to tthe Beta pictoris moving group