I wrote a very extensive piece about the lost planet of Mondas back in 2009, using only the 'Doctor Who' story "The Tenth Planet" for the basic information... information... information.
Here is all the pertinent information from the TARDIS Data Core Wiki, minus my own musings:
Mondas was the twin planet of Earth and original homeworld of the Cybermen. In ancient times, it was dislodged from its old position out into space when the Moon was formed.
Originally, Earth and Mondas occupied the same orbit in the solar system. It was stated that "Mondas" was another name for Earth in one of the ancient languages.
Mondas left that orbit and drifted on a journey to "the edge of space", (TV: The Tenth Planet) caused by the sudden arrival of a moon between Earth and Mondas. This upset the gravitational equilibrium of Mondas, causing it to escape its orbit.
Their only recourse now was to use Mondas' last remaining energy to return to the Earth's orbit and plunder her energy. (TV: The Tenth Planet)
In December 1986, the Cybermen invaded Antarctica while Mondas drew closer, draining Earth's energy to replace and supplement its own. However, the energy absorbed was too much, and Mondas disintegrated. The destruction of Mondas destroyed all of the Cybermen on Mondas and also killed all of the Cybermen on Earth, who were dependent upon Mondas for energy. As the planet plundered Earth's energy, the First Doctor's life-force was caught up in the maelstrom, triggering his regeneration into his second incarnation. (TV: The Tenth Planet)
Those who consider the audio dramas, the prose stories and the comics to be canon will notice that I didn't accept any of their additions to the Mondas mythos. I can only use what is played out on our TV screens. After that I can apply my Toobworld Dynamic logic to smooth out any discrepancies that might arise.
After all, Toobworld is my sandbox........
So I can see this being a picture of the Cyber-Controller pondering the return of Mondas to the Sol System in 1986.....