Astronomers from the Harvard-Smithsonian Center for Astrophysics have found an exoplanet with the longest year using data taken from the NASA Kepler spacecraft. The exoplanet, known as Kepler-421b, orbits its star about one thousand light years away from Earth every 704 days, at an estimated distance of 110 million miles away from the host star.

The Kepler space telescope has helped scientists make many extraordinary findings about other planets in the Universe.

In the most recent news, astronomers from the Harvard-Smithsonian Center for Astrophysics have found an exoplanet with the longest year using data taken from the NASA Kepler spacecraft.

The exoplanet, known as Kepler-421b, orbits its sun every 704 days, at an estimated distance of 110 million miles away from the host star.

Most of the exoplanets that have been found by astronomers are located closer to their host star, so they have shorter years.
For comparison, Mars completes one orbit around our sun every 780 days.

This discovery is significant not only because of the length of the transiting orbit, but also because the exoplanet is on the edge of what’s known as the frost line. That line divides the habitable and inhabitable zones of a solar system.

Kepler-421b is about the size of Neptune, or nearly four times the size of Earth, and temperatures on the exoplanet are around negative 135 degrees Fahrenheit.