The planet of Earth has changed little from OTL to here. Rather than drift further from the Sun in the Early Sol, the Earth-Luna system kept its integrity, and stayed where it currently lies in OTL. Humans reside over the planet, covering nearly all of its land surface, with a current population of around 5.6 billion, and a total human population of about 6.8 billion. Earth's surface is dominated by oceans, 75% specifically, a vast brine solution which has gone mostly unexplored even today. The humans are probably the least advanced race in Sol, due to their late formation of around three million years ago, quite late compared to the other sentient races. The Earth is part of the IPC, which has advanced its technology level considerably, with one space elevator in the Pacific ocean near Hawaii. Earthlings have yet to get used to a planet-wide government, seeing as how the Americans and Soviets nearly destroyed each other perhaps a decade ago. Rather than one unified government, they are employing the most powerful entities on each continent to police its area; the United States deals with N. America; Brazil with S. America; Russia and China working together on Asia; the EU over Europe; Australia is all by its lonesome; Africa for the longest time was a continent of warlords and dictators, until Nelson Mandela came into power in the 1980s after that Africa has been united and is considered to be one of the most peaceful regions on Earth, and Antarctica is too cold and barren to care about.
Humans are quite easily the latest forming species in Sol, having formed a mere three million years ago; a short time compared to other sentient who have had millennium to unify. Average Humans are roughly six feet tall, weighing ninety kilograms. Humans have hair mostly on top of their heads, though it is present in a few other places as well. Human civilization developed no more than seven thousand years ago, and even then it was isolated in northern Africa. For countless years they have built empires, some continent wide, some around the globe; some of British, some of the Mongolians, but there is one constant; they would fall a few centuries later. At one time, the two largest nations in modern days clashed, and Humanity was this close to bringing about its own end. With the presence of off-worlders, however, the aforementioned cold war thawed, and Humanity saw a common goal, a goal which had plagued them since two tribes first clashed; being better than the other guys. The Soviet Union, after talks with aliens, decided to disband itself, and the world knew peace. Technology exploded as human and alien minds clashed, creating everything we don't have in OTL; intelligent automatons, directed-energy weapons, hover cars, even a space elevator. (Wikipedia just happens to have a page on Humanity, check it out for more information: http://en.wikipedia.org/wiki/Human)