bryan (guest) 25 Feb 2011 00:12
this is posted by the NASA website regarding an answer to a question about Tyche, but according to this answer, if it exists, would it be at its closest distance to earth, or would it still be really far away, if u guys say 15000 AU, is that far or close when it comes to astronomers:
Q: Why is the hypothesized object dubbed "Tyche,
" and why choose a Greek name when the names of other planets derive from Roman mythology?
A: In the 1980s, a different companion to the sun was hypothesized. That object, named for the Greek goddess "Nemesis," was proposed to explain periodic mass extinctions on the Earth. Nemesis would have followed a highly elliptical orbit, perturbing comets in the Oort Cloud roughly every 26 million years and sending a shower of comets toward the inner solar system. Some of these comets would have slammed into Earth, causing catastrophic results to life. 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. However, it is still possible that the sun could have a distant, unseen companion in a more circular orbit with a period of a few million years — one that would not cause devastating effects to terrestrial life. To distinguish this object from the malevolent "Nemesis," astronomers chose the name of Nemesis's benevolent sister in Greek mythology, "Tyche."
