There is only one answer to the question of which man-made objects are the farthest from the earth. Voyager 1 and Voyager 2. These spacecraft have been traveling in interstellar space for 44 years.
The heliosphere is a vast area covered by the sun. Its boundary, which is in the shape of a bubble, is where it meets the interstellar medium. It also lies beyond the orbit of Pluto. This is the extent to which the effects of the solar wind are felt. The Voyager twins continue their journey beyond that.
Voyager 1 and Voyager 2 were spacecraft launched by NASA in 1977 to study the Solar System and extraterrestrial media.
They travel in different directions. Voyager 2 was the first man-made object to cross Saturn, Uranus, Jupiter and the Solar System.
Even NASA had no guarantee that the spacecraft would survive so long or provide information.
Remember these are spacecraft that fly with a lifespan of just 5 years !!
In the hope of ever finding intelligent aliens, these twin brothers are still on a journey to infinity as messengers of mankind …