55 Cancri is an exoplanet in the orbit of its Sun-like host star 55 Cancri A. The mass of the exoplanet is about 8.08 Earth masses, and its diameter is about twice that of the Earth, thus classifying it as the first super-Earth detected around a main-sequence star, predating Gliese 876 d by nearly a year. It is also known as Janssen, and it exists around 41 light-years away from Earth. The planet is entirely uninhabitable.
Here are six facts about 55 Cancri e
- Detection: Like most extrasolar planets found before the Kepler mission, 55 Cancri e was discovered by identifying variations in its star’s radial velocity. It was accomplished by making sensitive dimensions of the Doppler shift of the color of 55 Cancri A. At the time of its detection, three other planets were known orbiting the star. After considering these planets, a signal at around 2.8 days remained, which could be resolved by a world of at least 14.2 Earth masses in a very close orbit.
- Hotter than hell: Radiation on 55 Cancri e exceeds Gliese 436 b. The planet’s side facing its star has temperatures more than 1,700 degrees Celsius, hot enough to melt iron. Infrared mapping with the Spitzer Space Telescope indicated an average front-side temperature of 2,573 K (2,300 °C; 4,172 °F) and an average back-side temperature of approximately 1,371 °C.
- Mass: The radial velocity method used to discover 55 Cancri e obtains the minimum weight of 7.8 times that of Earth or 48% of Neptune mass. The transition shows that its inclination is about 83.4 ± 1.7, so the real mass is close to the lowest. 55 Cancri e is also coplanar with b. The planet is very likely to be tidally locked, meaning permanent dayside and an unchanging night side. 55 Cancri e has a black and white side, with no grey areas. Politics won’t survive there for sure. Ha.
- Gases: In 2016, NASA’s Hubble Space Telescope detected helium, hydrogen, and hydrogen cyanide, but no water vapor, in the atmosphere of 55 Cancri e, the first time the atmosphere of a super-Earth exoplanet was investigated.
- Volcanic Eruption: Large surface-temperature differences on 55 Cancri e have been connected to potential volcanic activity freeing large clouds of dust that blanket the planet and prevent thermal emissions.
- This ‘diamond-rich super-Earth’: A portrait of the planet’s interior in 2012 proposed that 55 Cancri e is made up of carbon (principally as graphite and diamonds). The surface of this planet is probably covered in diamond and graphite rather than granite and water. This is disputed in the scientific community, and hopefully, we will know the proper conclusion soon.