class 6th state board
chapter 2.4 Anak Krakatoa
Maharashtra board
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please add me brainliest
uggests that some 4.47 billion years ago—a mere 60 million years after Earth took shape and 40 million years after the moon formed—a moon-size object sideswiped Earth and exploded into an orbiting cloud of molten iron and other debris.
The metallic hailstorm that ensued likely lasted years, if not centuries, ripping oxygen atoms from water molecules and leaving hydrogen behind. The oxygens were then free to link with iron, creating vast rust-colored deposits of iron oxide across our planet's surface. The hydrogen formed a dense atmosphere that likely lasted 200 million years as it ever so slowly dissipated into space.
After things cooled down, simple organic molecules began to form under the blanket of hydrogen. Those molecules, some scientists think, eventually linked up to form RNA, a molecular player long credited as essential for life's dawn. In short, the stage for life's emergence was set almost as soon as our planet was born.
That scenario captivated participants at an October 2018 conference here, where geologists, planetary scientists, chemists, and biologists compared notes on the latest thinking on how life got its start. No rocks or other direct evidence remain from the supposed cataclysm. Its starring role is inferred because it would solve a bevy of mysteries, says Steven Benner, an origin of life researcher at the Foundation for Applied Molecular Evolution in Alachua, Florida, who organized the Origins of Life Workshop.
The metal-laden rain accounts for the distribution of metals across our planet's surface today. The hydrogen atmosphere would have favored the emergence of the simple organic molecules that later formed more complex molecules such as RNA. And the planetary crash pushes back the likely birthdate for RNA, and possibly life's emergence, by hundreds of millions of years, which better aligns with recent geological evidence suggesting an early emergence of life.
A head start
Multiple lines of evidence from chemistry, biology, and geology help explain how RNA could have emerged, leading to the first life, surprisingly soon after Earth formed.
