"where a massive rogue planet enters into the solar system and interposes itself between the Earth and Sun, thus shading the Earth and dropping its temperature

"where a massive rogue planet enters into the solar system and interposes itself between the Earth and Sun, thus shading the Earth and dropping its temperature the required amount. Sort of like a month long solar eclipse" For our planet's distance from the sun, I have a hard time imagining how anything without self propulsion could maintain a stable orbital position to cast a shade over us for a long enough period (e.g. a month).