Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2016 April 5

Cancri 55 e: Climate Patterns on a Lava World
Illustration Credit: NASA, JPL-Caltech, Spitzer Space Telescope, Robert Hurt (Spitzer, Caltech)

Explanation: Why might you want to visit super-earth Cancri 55 e? Its extremely hot climate would be a deterrent, and fresh lava flows might be common. Discovered in 2004, the planet Cancri 55 e has twice the diameter of our Earth and about 10 times Earth's mass. The planet orbits its 40 light-year distant Sun-like star well inside the orbit of Mercury, so close that it is tidally locked, meaning that it always keeps the same face toward the object it orbits -- like our Moon does as it orbits the Earth. Astronomers have recently measured temperature changes on this exoplanet using infrared observations with the Spitzer Space Telescope. Given these observations, an artist created the featured video with educated guesses about what one revolution of Cancri 55 e might look like. Depicted are full phase, when the planet is fully illuminated, and new (dark) phase when it passes near the line of sight to Earth. The illustrated red bands on the Cancri 55 e indicate bands of lava that might flow on the planet. A recent density determination for 55 Cancri e show that this exoplanet is not made primarily of oxygen, as are the inner planets in our Solar System, but rather of carbon. Therefore, one reason to visit Cancri 55 e might be to study its core, because this planet's great internal pressure might be sufficient to make the carbon found there into one huge diamond.

New for Programmers: NASA Open API for APOD
Tomorrow's picture: magnetic jupiter

< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.