Fig. 1
An artist’s concept of a newly discovered planet orbiting a star technically known as GJ 436.
Credit: NASA/JPL-Caltech
 

Astronomers using NASA's Spitzer Space Telescope (SST), a sophisticated telescope exploring the cosmos in infrared light from orbit around the Sun, have detected what they believe is an alien planet orbiting a nearby star. The possible planet is estimated to be just two-thirds the size of Earth, one of the smallest planets ever spotted outside the Solar System. Planets orbiting beyond the Solar System are termed exoplanets or extrasolar planets. In their earnest search for exoplanets, astronomers have discovered approximately 800 exoplanets, and hundreds of planet candidates await confirmatory observations.

The new exoplanet candidate, known as UCF-1.01, orbits the star GJ 436, which is located only 33 light-years away from Earth. UCF-1.01 might be the closest exoplanet to the Solar System that is smaller than Earth.

Although probably rocky in composition like Earth, UCF-1.01 would be highly inhospitable for life, as it orbits too close to its star. Thus, most probably it lacks an atmosphere, and might even have a molten surface, as shown in Fig. 1.

Evidence for UCF-1.01 turned up when astronomers were studying a previously known exoplanet, also orbiting the stars GJ 436, and is similar to the giant planet Neptune in size. It is depicted in the background in Fig. 1. The discovery of nearby small planets may ultimately lead to the finding of a habitable, Earth-like exoplanet.

References:

NASA
www.nasa.gov/

Spitzer Space Telescope
http://www.spitzer.caltech.edu/

Wikipedia
 

Aymen Mohamed Ibrahem
Senior Astronomy Specialist