<P> In 1984, Physicist Richard A. Muller postulated that the Sun has a heretofore undetected companion, either a brown dwarf or a red dwarf, in an elliptical orbit within the Oort cloud . This object, known as Nemesis, was hypothesized to pass through a portion of the Oort cloud approximately every 26 million years, bombarding the inner Solar System with comets . However, to date no evidence of Nemesis or the Oort cloud have been found, and many lines of evidence (such as crater counts), have thrown their existence into doubt . Recent scientific analysis no longer supports the idea that extinctions on Earth happen at regular, repeating intervals . Thus, the Nemesis hypothesis is no longer needed to explain current assumptions . </P> <P> A somewhat similar hypothesis was advanced by astronomer John J. Matese of the University of Louisiana at Lafayette in 2002 . He contends that more comets are arriving in the inner Solar System from a particular region of the postulated Oort cloud than can be explained by the galactic tide or stellar perturbations alone, and that the most likely cause would be a Jupiter - mass object in a distant orbit . This hypothetical gas giant was nicknamed Tyche . The WISE mission, an all - sky survey using parallax measurements in order to clarify local star distances, was capable of proving or disproving the Tyche hypothesis . In 2014, NASA announced that the WISE survey had ruled out any object as they had defined it . </P> <P> Space probes have yet to reach the area of the Oort cloud . Voyager 1, the fastest and farthest of the interplanetary space probes currently leaving the Solar System, will reach the Oort cloud in about 300 years and would take about 30,000 years to pass through it . However, around 2025, the radioisotope thermoelectric generators on Voyager 1 will no longer supply enough power to operate any of its scientific instruments, preventing any exploration by Voyager 1 . The other four probes currently escaping the Solar System either are already or are predicted to be non-functional when they reach the Oort cloud; however, it may be possible to find an object from the cloud that has been knocked into the inner Solar System . </P> <P> In the 1980s there was a concept for a probe to reach 1,000 AU in 50 years called TAU; among its missions would be to look for the Oort cloud . </P>

How long will it take voyager to pass through the oort cloud