O—S The blue graph shows the apparent percentage not the absolute number of marine animal genera becoming extinct during any given time interval. It does not represent all marine species, just those that are readily fossilized.
Impactor comparisons[ edit ] "For comparison, the Martian moon Deimos is 12 km". Check out the page on Deimos. Assuming data on that page is correct the comparison here is wrong. Phobos are much closer in size to 12km than Deimos is.
On impact with the sea, rock and the sea where they met would be dissociated into atoms, stripped of electrons to form an extremely hot plasma cloud, a very dense gas which would then rise, not through convection but because there was nowhere else to go, forming a fireball carrying between 6, and 60, billion tonnes of matter into the atmosphere at about escape velocity so that some could have gone into orbit.
The hot, dense, plasma would have been almost disc shaped, rising extremely quickly as a very wide barrel of fire. That, of course, is just the start. It's an ancient source, from the days before macs roamed the earth, but on that basis the image at Katie seems pretty reasonable.
The info's not here, let me know if you'd like to add to it to expand the article Im gonna go with my professor and say wikipedia is wrong Consider revising the phrase "who first suggested it in " to "who popularized the theory in ".
Iridium is rare because it preferentially segregated into a phase molten nickel-iron that was dense, not because iridium itself is dense. Uranium, one of the densest elements, is enriched in the Earth's crust relative to the Earth as a whole, because the element tends to move into the low density silicate minerals of the continental crust.
The sentence above is what I was taught in Science at school forty years ago. That is, the extraterrestrial nature is not due to either the presence of iridium or the amount of it; rather, it is indeed the isotope ratio that marks it as different.
The problem is, from all that i have read in Wikipedia on this and related topics, this article here is the only one that says it. Pretty well all other articles either suggest, or state outright, that it is the sudden abundance of iridium that is the evidence of the ET impact.
Where to go from here? Is this still seen to be correct? The isotopic composition is the most suggestive of ET origin? And to a more practical point, should this possibly very fine point be propagated in other pages? Please take a moment to review my edit.
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If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool. If you found an error with any archives or the URLs themselves, you can fix them with this tool.At the same time, in , geologist Walter Alvarez and his father, Nobel Prize-winning scientist Luis Walter Alvarez, put forth his hypothesis that a large extraterrestrial body had struck Earth.
In , unaware of Penfield's discovery, University of Arizona graduate student Alan R. Hildebrand and faculty adviser William V. Boynton published a draft Earth . Alvarez hypothesis has been listed as a level-5 vital article in Science, Earth science.
If you can improve it, please do. This article has been rated as Start-Class. An international panel found in favor of a theory by Luis and Walter Alvarez that an asteroid impact with Earth 65 million years ago triggered the mass extinction of the dinosaurs.
Introduction Though perhaps best known throughout the world for his science fiction, Isaac Asimov was also regarded as one of the great explainers of science. This event changed the planet’s climate and is widely believed to have triggered a mass extinction of species — including the end of the dinosaurs.
clay Fine-grained particles of soil that stick together and can be molded when wet. (YouTube link) Have you ever wanted to dance like a professional?
Of course! New motion capture software developed by a team at Berkeley can transfer body moves from one person to another- on video.