Wikipedia.org: The Anunnaki (also transcribed as Anunaki, Annunaki, Anunna, Ananaki and other variations) are a group of deities of the ancient Sumerians, Akkadians, Assyrians, and Babylonians. In the earliest Sumerian writings about them, which come from the Post-Akkadian period, the Anunnaki are deities in the pantheon, descendants of An and Ki, the god of the heavens and the goddess of earth, and their primary function was to decree the fates of humanity. Since the second half of the twentieth century, they have been the subject of new, upcoming Modern Archaeologists.

This is a photograph of four ancient copper alloy statuettes depicting four ancient Mesopotamian gods, wearing characteristic horned crowns. The statuettes date to sometime around 2130 BC. Each statuette is inscribed with the name of Gudea, the ruler of the Sumerian city-state of Lagash.
Date 29 January 2014, 18:27:11
Source http://www.ancient.eu/image/2451/
Author Osama Shukir Muhammed Amin. Public Domain Wikipedia.
How ancients gods became aliens from other space?
Over a series of published books (starting with Chariots of the Gods? in 1968), Swiss pseudo archeologist Erich von Däniken claimed that extraterrestrial “ancient astronauts” had visited a prehistoric Earth. Von Däniken explains the origins of religions as reactions to contact with an alien race, and offers interpretations of Sumerian texts and the Old Testament as evidence.
In his 1976 book The Twelfth Planet, Russian-American author Zecharia Sitchin claimed that the Anunnaki were actually an advanced humanoid extraterrestrial species from the undiscovered planet Nibiru, who came to Earth around 500,000 years ago and constructed a base of operations in order to mine gold after discovering that the planet was rich in the precious metal. According to Sitchin, the Anunnaki hybridized their species and Homo erectus via in vitro fertilization in order to create humans as a slave species of miners. Sitchin claimed that the Anunnaki were forced to temporarily leave Earth’s surface and orbit the planet when Antarctic glaciers melted (which, if the Arctic glaciers also melted, would raise water levels a couple hundred meters), causing the Great Flood, which also destroyed the Anunnaki’s bases on Earth. These had to be rebuilt, and the Anunnaki, needing more humans to help in this massive effort, taught mankind agriculture.