Earth has Two Sisters within the Solar System, both which probably, at their protoplanet stage were the same as us.
We begin with Mars. Mars had a terrible fault. Firstly, it was the smallest of the Three, and secondly, it was the furthest away from the Sun. The evidence shows that Mars had an atmosphere, had weather, and had water, and then something went wrong.
It was too cold. It went cold, and the core Froze. The core was really important because a hot spinning metalic core creates a magnetic shield around the planet. No hot core, and the magnetic shield collapses, and when that happens the solar winds can rip the whole atmoshphere away, and then everything is lost to space.
Venus went the opposite way. It was the same size as Earth but it got to hot. It had an atmosphere, but due to being just slightly closer to the sun, the oceans evaporated, and it never got cold enough to rain. This was fine until the heat caused the core to speed up and get hotter, and the surface opened up like boils with lots of volcano. The dust went up...and there was no rain to wash it away. Rather then cooling the planet, the dust actually insulated the planet...it got so warm and such a heavy atmosphere, it crushed anything it had under too much pressure.
But Earth was the correct size to keep its atmosphere, the correct tempriture, retained a molten core, kept its magnetic shield...et voila
Other interests....Io...Jupiters closest moon, which is frozen...or at least has no hot core...but is so close to jupiter and is caught between Jupiters gravity and the other moons, that it actually physically changes shape during the Orbit, causing tares which of course get hot...its the most volcanically active place in the known universe....and two Moons away from it, a Frozen moon, which is far enough to stay frozen, but still splits and cracks when Jupiter makes it change shape...It has a solid core...and a liquid ocean of water under the ice (kept warm by Jupiter...but not warm enough to end up like Io) they think that the sort of bacterial shyte around the volcanic vents in our oceans could live their...of course...with a solid core...there might not be any vents...but the oceans are deeper then ours...and to the best of our knowledge there is no land...its an ocean moon.