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The theory of panspermia speculates that life on Earth may have come from biological matter carried by space dust [93] or meteorites. [94] While current geochemical evidence dates the origin of life to possibly as early as 4.1 Ga, and fossil evidence shows life at 3.5 Ga, some researchers speculate that life may have started nearly 4.5 billion ...
The Hadean (/ h eɪ ˈ d iː ə n, ˈ h eɪ d i ə n / hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four known geologic eons of Earth's history, starting with the planet's formation about 4.6 billion years ago [4] [5] (estimated 4567.30 ± 0.16 million years ago [2] set by the age of the oldest solid material in the Solar System — protoplanetary disk dust particles — found as ...
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
The earliest life on Earth arose at least 3.5 billion years ago. [16] [17] [18] Earlier possible evidence of life includes graphite, which may have a biogenic origin, in 3.7-billion-year-old metasedimentary rocks discovered in southwestern Greenland [19] and 4.1-billion-year-old zircon grains in Western Australia. [20] [21]
ɑːr ˈ k iː ə n / EE-oh-ar-KEE-ən; also spelled Eoarchaean) is the first era of the Archean Eon of the geologic record. It spans 431 million years, from the end of the Hadean Eon 4031 Mya to the start of the Paleoarchean Era 3600 Mya. Some estimates place the beginnings of life on Earth in this era, while others [2] place it earlier.
NASA Finds Evidence of Past Martian Microbial Life buradaki - Getty Images In its ancient past, Mars likely contained many of the necessarily ingredients for microbial life to flourish on its surface.
Lead isotope isochron diagram showing data used by Patterson to determine the age of Earth in 1956. Most geological samples from Earth are unable to give a direct date of the formation of Earth from the solar nebula because Earth has undergone differentiation into the core, mantle, and crust, and this has then undergone a long history of mixing ...