Earth
Earth is the home planet of Humans (and some human-alien hybrids) and many animal life forms, located in the Solar System, and the current home planet of Atomic Betty as well as the new Galactic Guardian Headquarters. Earth is the largest of the four terrestrial planets, and orbits a yellow dwarf star, the Sun. Earth has got one natural moon, the Moon.
Earth has got temperature of approximately 15 degrees Celsius (59 degrees Fahrenheit), making it be cooler than Mercury and Venus, but at least more warm than Mars and outer planets.
It formed approximately 4.5 billion years ago, and life has existed here for at least 3.5 billion years. Currently, it has several large land masses including North America, South America, Europe, Africa, Asia, Oceania and Antarctica which divied into countries (196 recgonized and 9 unrecgonized) and 61 territories. The rest of the planet, some three-quarters of it, is covered in five oceans (Atlantic, Pacific, Indian, Arctic and the Antarctic). It has two hemispheres divided by the Equator, the Northern and Southern Hemispheres. As such, seasons can different from hemisphere (e.g. it is winter in the Northern Hemisphere while it is summer in the Southern Hemisphere). Earth is the only known planet in the Solar System to ever provide life (sentient or otherwise).
Earth is the constant target of alien threats, most prominently, Maximus' many attempts to find and destroy it.
An odd thing about the planet is that a great deal of alien activity happens on Earth which isn't a trans-galactic level civilization. This has led to the majority of the plot lines within the Atomic Betty series, as well as a major story arc within Mission: Earth.
Earth is regarded as a "Cesspool" of the galaxy by several people, including Maximus I.Q., DeGill once referred to it as a "nondescript, who-cares place"