The "ecliptic plane" is the imaginary flat surface that represents the path of the Sun as seen from Earth. It is like a flat highway in space where all the planets in our solar system move around, including Earth. Full definition
On December 13, 2005, a team of astronomers (led by Lynne Allen) announced the discovery of a new planetary body between one - fifth to one half the size of Pluto, found during routine operation of the Canada - France Ecliptic Plane Survey (CFEPS) as part of the Legacy Survey on the Canada France Hawaii Telescope (CFEPS press release). (solstation.com)
Pulled by our star's gravity, on Sept. 9 A / 2017 U1 approached within 40 million kilometers of the sun — well within the orbit of Mercury — before being flung back up and out of the ecliptic plane in the direction of the constellation Pegasus at nearly 44 kilometers per second. (scientificamerican.com)
Based on these analyses, A / 2017 U1 came from the direction of the constellation Lyra, swooping in from high above the ecliptic plane in which the sun's planets orbit at a breathtaking 25 kilometers per second. (scientificamerican.com)