A planet, possibly four times the mass of Jupiter and with a lunar system, could be lurking in our solar system's outermost area, two US scientists theorize。

　　University of Louisiana researchers said if "Tyche" exists, the confirmed number of planets in our solar system would return to nine, with Pluto remaining a dwarf planet, DiscoveryNews.com reported Wednesday。

　　Astrophysicists John Matese and Daniel Whitmire analyzed comets passing through the inner solar system, discovering many of them had strange orbits。

　　The scientists said they believe the comets' orbits could be affected by the potential mystery planet, composed of hydrogen and helium, likely sucked into our solar system after being formed around another star。

　　Matese and Whitmire have been trying to track down Tyche's existence since 1999, but the majority of the astronomical community hasn't expressed confidence about Tyche's existence, DiscoveryNews.com said。

　　Ned Wright, principal investigator for NASA's Wide-Field Infrared Survey Explorer mission, told DiscoveryNews the theory behind Tyche is based on "ordinary evidence for an extraordinary claim."

　　两位美国科学家推断太阳系的遥远边际还可能存在一颗星球，它大概是木星体积的四倍，拥有自己的卫星系统。

　　《发现新闻》网站周三报道，路易斯安娜大学的研究者称如果这颗称为"堤喀"的星球真的存在，加上冥王星这个矮行星，太阳系的星球数量将变为9颗。

　　天体物理学家约翰•马特斯和丹尼尔•惠特米尔分析了太阳系内部的彗星运转，发现许多彗星的运行轨道都非常奇特。

　　科学家们称他们认为彗星轨道可能受到这颗未知星球的影响，这颗星球主要由氢气和氦气组成，可能在另一颗星球旁形成后被吸入太阳系。

　　这家网站报道称马特斯和惠特米尔自从1999年以来一直试图证明堤喀的存在，但大部分天文界人士对它的存在将信将疑。

　　美国宇航局大视场红外巡天探测者计划的主要调查者内德•莱特对《发现新闻》说这项关于堤喀的理论是基于"大胆的设想和实在的证据"。