A year is defined as such by a lot of things; like the cycle of the seasons and the time it takes for the Earth to complete a single orbit around the Sun. The latter, in turn, is dictated by Earth's distance from the Sun, which explains why a Martian year isn't the same as a year on Earth (despite the same amount of time technically having passed). A Martian year differs from a year on Jupiter; a year on Jupiter differs from a year on Saturn and so on and so forth, extending all the way to Neptune and beyond.
Through the hundreds of planets we've found using various exoplanet detection techniques, we've seen a handful of exoplanets that orbit their parent star from such a long distance, their years drag on for more than a thousand Earth-years. Now, astronomers have found a world so distant, it would take 80,000 YEARS for the planet to complete one full orbit around its mother star (the longest "year" yet).
Meet GU Psc B:
The planet, dubbed GU Psc b, is situated 2,000 times farther away from its parent star than Earth is from the Sun (we call this distance 1 AU, or one "astronomical unit"). 1 AU covers more than 92,960,000 miles/149,600,000 km), which means that GU Psc b is more than 185,920,000,000 miles/299,209,236,480 km away from its star.
In order to derive the information about the planet's orbital period, astronomers took a look at the real estate surrounding the planet and its star; not just in optical light, but in ultraviolet and infrared light as well, which allowed them to infer many things that can't normally be discerned in visible-light images. Infrared is most useful, as light at this wavelength can single out a planet or an unremarkable star by looking for heat signatures alone. Plus, according to Naud, one of the researchers, "Planets are much brighter when viewed in infrared rather than visible light, because their surface temperature is lower compared to other stars," he said.
Once they gathered the multi-wavelength information, it was easy enough to uncover the object's mass. Astronomers determined that the exoplanet weighs as much as 13 Jupiter-sized bodies combined and has a surprisingly hot temperature of about 1,500°F/800°C.
GU Psc b first came on our radar when astronomers were looking at a newbie grouping of stars, called AB Doradus. Given their young age and pristine conditions, stars belonging to these small clusters are like magnets to astronomers, as they make planets much easier to single out despite the background noise. Only when they probed 90 stars lurking within the region, they were only able to spot out one potential planet. Perhaps it has some less bizarre neighbors hiding out, but that remains to be seen.
If not, there is still much to be learned about the new planet. Additional information is needed before we can pinpoint the object's composition, but you needn't worry about the implications of finding life on the planet, as it it composed almost entirely of gas. Therefore, there's no chance that it harbors any creatures that bear even a passing resemblance to humans, but other, more exotic forms of life can not be, or at least shouldn't be, ruled out.
Where Other Planets Rank:
Most of the information used to put together this graphic came from the Extrasolar Planets Encylopedia catalog. Some of the orbital periods listed here might not match to the letter, as some sites give conflicting numbers. The planets are also not to-scale and in some cases, they aren't meant to be renderings of the planet they represent. Renderings can't be generated without knowing a lot of information about the composition and atmospheric conditions of any given planet. Moreover, calculating these estimates isn't an exact science.