“Sedna”造句，怎麼用Sedna造句

Perhaps a massive unseen object is responsible for Sedna's mystifying orbit, its gravitational influence keeping Sedna fixed in that far-distant portion of space.

一顆近期被發現的褐矮星“賽德娜”(Sedna)有一個超長的橢圓形的繞太陽的軌道。