Answer:
i don't know if this well help or not but what i found
A Hubble Space Telescope image of a star-forming region of Nebula M16 (Eagle Nebula).
Asteroid Ida and its moon as imaged by the Galileo spacecraft in 1993. The spacecraft was about 10,500 kilometers (6,500 miles) from the asteroid.
Explanation:
The Archean Eon and the Hadean
The Archean eon, which preceded the Proterozoic eon, spanned about 1.5 billion years and is subdivided into four eras: the Neoarchean (2.8 to 2.5 billion years ago), Mesoarchean (3.2 to 2.8 billion years ago), Paleoarchean (3.6 to 3.2 billion years ago), and Eoarchean (4 to 3.6 billion years ago).*
If you were able to travel back to visit the Earth during the Archean, you would likely not recognize it as the same planet we inhabit today. The atmosphere was very different from what we breathe today; at that time, it was likely a reducing atmosphere of methane, ammonia, and other gases which would be toxic to most life on our planet today. Also during this time, the Earth's crust cooled enough that rocks and continental plates began to form.
It was early in the Archean that life first appeared on Earth. Our oldest fossils date to roughly 3.5 billion years ago, and consist of bacteria microfossils. In fact, all life during the more than one billion years of the Archean was bacterial. The Archean coast was home to mounded colonies of photosynthetic bacteria called stromatolites. Stromatolites have been found as fossils in early Archean rocks of South Africa and western Australia. Stromatolites increased in abundance throughout the Archean, but began to decline during the Proterozoic. They are not common today, but they are doing well in Shark Bay, Australia (see photo below).
The sun formed within such a cloud of gas and dust, shrinking in on itself by gravitational compaction until it began to undergo nuclear fusion and give off light and heat. Surrounding particles began to coalesce by gravity into larger lumps, or planetesimals, which continued to aggregate into planets. "Left-over" material formed asteroids and comets, like asteroid Ida, above right.
Because collisions between large planetesimals release a lot of heat, the Earth and other planets would have been molten at the beginning of their histories. Solidification of the molten material into rock happened as the Earth cooled. The oldest meteorites and lunar rocks are about 4.5 billion years old, but the oldest Earth rocks currently known are 3.8 billion years. Sometime during the first 800 million or so years of its history, the surface of the Earth changed from liquid to solid. Once solid rock formed on the Earth, its geological history began. This most likely happened prior to 3.8 billion years, but hard evidence for this is lacking. Erosion and plate tectonics has probably destroyed all of the solid rocks that were older than 3.8 billion years. The advent of a rock record roughly marks the beginning of the Archean eon.
Resources and references
Bengtson, S. (ed.) 1994. Early Life on Earth. Nobel Symposium 84. Columbia University Press, New York.
Schopf, J.W. (ed.) 1983. Earth's Earliest Biosphere: Its Origin and Evolution. Princeton University Press, Princeton. 543 pp.
Read more about Shark Bay and its stromatolites or stromatolites in general on Wikipedia.
Learn more about the Archean and Hadean on Wikipedia.
Find out more about the Precambrian paleontology and geology of North America at the Paleontology Portal.
