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Astronomers: A comet fragment, not an asteroid, killed off the dinosaurs Jupiter's gravity pushed comet toward Sun; comet was ripped apart by tidal forces. Jennifer Ouellette, ArsTechnica, February 15, 2021 https://arstechnica.com/science/2021/02/astronomers-a-comet-fragment-not-an-asteroid-killed-off-the-dinosaurs/ The open access paper is: Siraj, A. and Loeb, A., Breakup of a Long-Period Comet as the Origin of the Dinosaur Extinction. Scientific Reports volume 11, Article number: 3803 (2021) https://www.nature.com/articles/s41598-021-82320-2 https://www.cfa.harvard.edu/~loeb/SLD.pdf Keep warm and safe out there Paul H.

Asteroid shower rained space rocks on Earth and the moon 800 million years ago By Charles Q. Choi, SpaceCom, July 21, 2020 Asteroid shower on the Earth-Moon system 800 million years ago revealed by lunar craters by Osaka University, PhysOrg, July 21, 2020 The open access paper is: Terada, K., Morota, T. & Kato, M. Asteroid shower on the Earth-Moon system immediately before the Cryogenian period revealed by KAGUYA. Nature Communications (2020). DOI: 10.1038/s41467-020-17115-6 Yours, Paul H.

There are a lot meteorite and extraterrestrial videos from the SETI Institute web page. several include meteorites and asteroids. They included. Late, Late Heavy Bombardment - Bill Bottke (SETI Talks) https://www.youtube.com/watch?v=4MMYTzb0L_s Late Heavy Bombardment - Don Lowe (SETI Talks) SETI InstitutePublished on Aug 3, 2010 https://www.youtube.com/watch?v=JAMm_0t5kcM 1I/‘Oumuamua, The First known Interstellar Visitor - Matija Cuk & Meg Schwamb (SETI Talks 2018) https://www.youtube.com/watch?v=b_vAcv7JGhQ Sutters Mill Meteorite Fall - Peter Jenniskens (SETI Talks) https://www.youtube.com/watch?v=zcSXmCrXbUo&list=PL7B4FE6C62DCB34E1&index=38 SETI Talks archive - http://seti.org/talks https://www.youtube.com/playlist?list=PL7B4FE6C62DCB34E1 Yours, Paul H.

Below are a selection of news articles, of varying sensationalism, to remind everyone what crowded and potentially dangerous solar, neighborhood that we occupy. NASA Asteroid Hunter Explains the Risks that Near Earth Objects Pose to Planet, Hanna Osborne, Newsweek, http://www.newsweek.com/asteroid-day-nasa-risk-earth-neos-629965 Space rock found to be travelling With Earth Scientists have discovered that Earth is being tailed by an Asteroid, Sean Martin, Express. http://www.express.co.uk/news/science/868068/ASTEROID-belt-nasa-end-of-the-world-earth-orbit Asteroid 2012 TC4: Space rock could come back and Smash into Earth in the near future The asteroid which had a near miss with Earth could come back and smash into the planet in the future, researchers have warned, Sean Martin, Express, Oct 13, 2017 http://www.express.co.uk/news/science/866149/Asteroid-2012-TC4-hit-Earth-end-of-the-world-nasa-esa How We Discovered, Lost, and Rediscovered the First Asteroid. It was a lot of math and staring through telescopes. Popular Mechanics http://www.popularmechanics.com/space/solar-system/a28667/how-we-discovered-lost-and-rediscovered-the-first-asteroid/ Samples Brought Back From Asteroid Itokawa Reveal 'Rubble Pile' Had a Violent Past, Curtin University Posted October 18, 2017 http://spaceref.com/asteroids/samples-brought-back-from-asteroid-itokawa-reveal-rubble-pile-had-a-violent-past.html Near-Earth Objects News https://watchers.news/category/near-earth-objects/ What I am worried about is not the asteroids that we know about. What worries me are the asteroids that we do not know about and appear abruptly out of the darkness like a drunk driver on a New Orleans street. Go read “Asteroid 2017 TF5 flew past Earth at 0.73 LD, 4 days before discovery, October 16, 2017 https://watchers.news/2017/10/16/asteroid-2017-tf5/ Unlike the dinosaurs, we have, if we want it, the technology to possibly defend ourselves from wayward asteroids. Yours, Paul H.

Large meteorite impacts drove plate-tectonic processes on the early Earth, PhysOrg, September 26, 2017 https://phys.org/news/2017-09-large-meteorite-impacts-drove-plate-tectonic.html Did meteorites create the Earth’s tectonic plates? Cosmos, September 26, 2017 https://cosmosmagazine.com/geoscience/did-meteorites-create-the-earth-s-tectonic-plates The paper is: O’Neill, C., Marchi, S., Zhang, S., and Bottke, W., 2017. Impact-driven subduction on the Hadean Earth Nature Geoscience (2017) doi:10.1038/ngeo3029 Received 12 December 2016 Accepted 22 August 2017 Published online 25 September 2017 http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo3029.html?foxtrotcallback=true Another article is: Australian rocks suggest early Earth may not have had plate tectonics, Cosmos, September 28, 2017 https://cosmosmagazine.com/geoscience/tremors-shake-tectonic-plate-theory Plate Tectonics May Have Begun a Billion Years After Earth's Birth, Live Science, September 21, 2017 https://www.livescience.com/60478-plate-tectonics-gets-new-age.html The paper is: Johnson, T.E., Brown, M., Gardiner, N.J., Kirkland, C.L. and Smithies, R.H., 2017. Earth’s first stable continents did not form by subduction. Nature, 543(7644), pp.239-242. https://www.nature.com/nature/journal/v543/n7644/abs/nature21383.html Yours, Paul H.