55 Cancri e Diamond Lava Planet

55 Cancri e Diamond Planet: Type, Size, Mass, Atmosphere, Distance from Earth, Facts, Temperature

55 Cancri e Diamond Planet

A Lava World in the Cosmic Neighborhood

55 Cancri e, also known as Janssen, has captured the imagination of astronomers and space enthusiasts alike. This super-Earth exoplanet orbits a G-type star named Copernicus, located a mere 41 light years away from Earth. Discovered in 2004, this celestial body has unique characteristics that set it apart in the vast expanse of our galaxy.

The Sparkling Skies of Janssen

While the molten surface of 55 Cancri e is deemed uninhabitable, its sister planet, Galileo, adds a touch of mystique. Silicates in the atmosphere condense into clouds on the tidally-locked planet's dark side, reflecting the lava below and creating a celestial spectacle—a sparkling sky.

55 Cancri e Diamond Planet Type

Diamond Super-Earth: 55 Cancri e is classified as a super-Earth exoplanet, about twice the size of Earth. Initially hailed as the "diamond planet" due to speculations about its carbon-rich composition, ongoing studies and debates have added layers of complexity to understanding its true nature.

55 Cancri e Planet

55 Cancri e Diamond Planet Size Compared to Earth in Percentage

Approximately 200%: 55 Cancri e is roughly twice the size of Earth, making it a super-Earth. This puts its size at approximately 200% of Earth's diameter.

55 Cancri e Diamond Planet Mass Compared to Earth in Percentage

Approximately 425%: With a mass of 8.08 Earths, 55 Cancri e is significantly more massive than our home planet. Its mass is approximately 425% that of Earth.

What is The Surface Temperature of 55 Cancri e Diamond Planet

Variable Extreme Temperatures: The surface temperature of 55 Cancri e exhibits extreme variations. The day side reaches scorching temperatures exceeding 3,770 K (3,500 °C; 6,330 °F), hot enough to melt iron, while the night side experiences temperatures below 1,650 K (1,380 °C; 2,510 °F).

55 Cancri e Diamond Planet Atmosphere Composition

Complex Composition: The atmospheric composition of 55 Cancri e is a subject of ongoing research and debate. Initial findings in 2016 suggested the presence of hydrogen, helium, and hydrogen cyanide. However, more recent observations indicate an atmosphere with a pressure of about 1.4 bar, possibly containing nitrogen and oxygen, akin to Earth's atmosphere.

55 Cancri e Diamond Planet Distance from Earth in Light Years

Approximately 41 Light Years: 55 Cancri e orbits a star called Copernicus, situated about 41 light years away from Earth. Its proximity makes it a relatively nearby exoplanet in our cosmic neighborhood.

55 Cancri e Lava Planet

10 Interesting Fun Facts About 55 Cancri e Diamond Planet

  1. Lava Seas: Scientists believe 55 Cancri e is covered in flowing lava seas, creating a daunting landscape.
  2. Sparkling Skies: Silicates in the atmosphere create clouds on the dark side, reflecting the lava below and making the skies sparkle.
  3. Discovery Date: 55 Cancri e was officially discovered on August 30, 2004.
  4. First Super-Earth: It was the first super-Earth discovered around a main sequence star.
  5. Tidal Locking: The planet is extremely likely to be tidally locked, resulting in a permanent day side and night side.
  6. Radiation Levels: It receives more radiation than the hot Neptune, Gliese 436 b.
  7. Atmospheric Analysis: NASA's Hubble Space Telescope successfully analyzed its atmosphere, detecting hydrogen, helium, and hydrogen cyanide.
  8. Diamond Speculation: Initial speculations suggested the planet could be composed of diamonds and graphite.
  9. Variable Gas Torus: Observations in 2022 indicated variations in planetary transit depths, possibly due to large-scale volcanism or a variable gas torus.
  10. Controversial Composition: Ongoing debates surround its composition, with theories ranging from a carbon-rich solid planet to a water-rich atmosphere.

Unveiling Janssen's Secrets

Discovery and Characteristics

55 Cancri e is a remarkable super-Earth, boasting a mass of 8.08 Earths and completing an orbit around its star in a mere 0.7 days. The discovery, announced in 2004, marked a significant milestone as the first super-Earth found around a main sequence star, predating similar discoveries.

Naming Janssen In 2015, the International Astronomical Union (IAU) named the planet Janssen, honoring Zacharias Janssen, a historical figure associated with the invention of the telescope.

Peering into the Atmosphere

Atmospheric Composition

Recent studies using NASA's Hubble Space Telescope have provided insights into 55 Cancri e's atmosphere. Hydrogen, helium, and hydrogen cyanide have been detected, shedding light on the unique composition of this distant world.

A Diamond Planet?

Initial speculation suggested the possibility of 55 Cancri e being a diamond planet due to its high density and extreme conditions. The atmosphere's carbon-rich nature raises intriguing questions about the potential presence of diamond formations within the planet.

Cancri e Planet

Tidal Locking and Extreme Temperatures

Perpetual Day and Night

Tidal locking has rendered 55 Cancri e with a permanent day side, where temperatures soar above 2,000 Kelvin—hot enough to melt iron. Infrared mapping by the Spitzer Space Telescope has revealed the stark temperature contrast between the day and night sides.

Surface-temperature Variations

Large variations in surface temperatures hint at possible volcanic activity. Observations suggest the presence of a global lava ocean, adding to the enigma of this exotic exoplanet.

A Diamond Planet's Composition Debate

Carbon-rich or Water Planet? Scientists have debated whether 55 Cancri e is a water planet or a solid planet made of carbon-rich materials. The absence of hydrogen in its Lyman-alpha signature during transit has led to speculations about carbon dioxide or even diamond formations within its composition.

Challenges to the Diamond Hypothesis

Challenges to the "diamond planet" theory arose when subsequent studies questioned the carbon-to-oxygen ratio. The host star's characteristics, cooler than the Sun and possessing more metals, raised doubts about the initial assumptions.

Continuing Exploration

Ongoing Studies and Future Observations

As technology advances, astronomers continue to delve into the mysteries of 55 Cancri e. Ongoing studies aim to refine our understanding of this intriguing diamond planet, offering new perspectives on its composition and atmospheric dynamics.


55 Cancri e engages in a fascinating orbital dance around its host star, 55 Cancri A. With an orbital period of only 0.7365 days, this super-Earth completes its journey in less than 18 hours. Its close proximity to the star has led to extreme temperatures on its day side, providing a unique perspective for astronomers.

Surface Features and Atmosphere

Observations from various telescopes, including the MOST space telescope and the Spitzer Space Telescope, have revealed the planet's intriguing surface and atmospheric characteristics. From large-scale volcanism to a possible "supercritical" fluid state, 55 Cancri e continues to puzzle scientists.

Composition Mystery

Diamonds and More?

While the "diamond planet" moniker has stirred excitement, ongoing debates about the planet's composition persist. Initial models suggested a carbon-rich interior, potentially forming diamonds and graphite. However, conflicting studies challenge these assumptions, highlighting the dynamic nature of scientific exploration.

Carbon-rich or Water World?

The initial suspicion of 55 Cancri e being a water planet has evolved into a broader consideration of its composition. The absence of hydrogen during transit has led researchers to explore carbon dioxide and other carbon-rich materials, keeping the door open to the possibility of diamond formations.

Challenges and Contradictions

Conflicting Data

Scientific understanding of 55 Cancri e is a journey marked by challenges and contradictions. Conflicting data regarding atmospheric components, from hydrogen cyanide to the absence of escaping helium, underscores the complexities of studying exoplanetary atmospheres.

Surface-Temperature Variability

Recent observations revealing large variations in planetary transit depths raise questions about the causes. Volcanic activity and the presence of a co-orbital gas torus are proposed explanations, adding layers to the ongoing investigation of this distant diamond planet.

Future Prospects and Beyond

Advancements in Observation

The advancements in observational technology promise a more detailed exploration of 55 Cancri e's mysteries. Future telescopes and missions may provide additional insights, refining our understanding of its composition, atmosphere, and surface dynamics.

Exploring Similar Exoplanets

The discoveries and challenges presented by 55 Cancri e contribute to the broader field of exoplanet research. As our understanding deepens, scientists can apply lessons learned from this unique super-Earth to the study of other distant worlds.


55 Cancri e, the diamond planet, remains a captivating subject of study, pushing the boundaries of our understanding of distant worlds. As our exploration tools evolve, we anticipate unveiling more secrets hidden within the sparkling skies of Janssen.

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