55 Cancri e (abbreviated 55 Cnc e, also known as Janssen / ˈ dʒ æ n s ən /) is an exoplanet orbiting a Sun-like host star, 55 Cancri A. The mass of the exoplanet is about eight Earth masses and its diameter is about twice that of the Earth.

Mar 28, 2025 · 55 Cancri e is a super Earth exoplanet that orbits a K-type star. Its mass is 7.99 Earths, it takes 0.7 days to complete one orbit of its star, and is 0.01544 AU from its star. Its discovery was announced in 2004.

A light curve of 7.5- to 11.8-micron light captured by NASA’s James Webb Space Telescope’s MIRI (Mid-Infrared Instrument) in March 2023 shows the decrease in brightness of the 55 Cancri system as the rocky planet 55 Cancri e moves behind the star, a phenomenon known as a secondary eclipse.

Jul 28, 2017 · 55 Cancri e is a super-Earth — about twice our planet's size — that zooms around its star in 18 days. It has a surface temperature of nearly 4,900 degrees Fahrenheit (2,700 degrees Celsius).

May 8, 2024 · 55 Cancri e is a super-Earth planet that appears composed of diamond-like carbon — now, thanks to the JWST, astronomers have found the world has "grown" a second atmosphere.

Jan 11, 2024 · New Webb data suggests that the hot super-Earth 55 Cancri e has an atmosphere, perhaps maintained by the planet’s magma ocean. One artist's illustration of 55 Cancri e shows a planet covered in lava flows, with only a wisp of rock-vapor for an atmosphere.

NASA explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery. Soar above an ocean of lava amid the sparkling clouds of 55 Cancri e.

May 26, 2022 · Illustration showing what exoplanet 55 Cancri e could look like, based on current understanding of the planet. 55 Cancri e is a rocky planet with a diameter almost twice that of Earth orbiting just 0.015 astronomical units from its Sun-like star.

Amendment 120: Step-2 Due Date Delayed and Other Changes to E.9 Space Biology and E.12 Physical Sciences.

Feb 5, 2019 · In addition to a new Exoplanet Travel Bureau poster celebrating a molten world called 55 Cancri e, space fans can enjoy a 360-degree visualization of the surface of the same planet, a multimedia journey into the life and death of planetary systems, and a major update to the popular Eyes on Exoplanets app.