(C) Daily Kos This story was originally published by Daily Kos and is unaltered. . . . . . . . . . . White to move and mate in two #530 - Asteroid Day [1] ['This Content Is Not Subject To Review Daily Kos Staff Prior To Publication.'] Date: 2024-07-02 June 30 was Asteroid Day. It is a day used to learn about asteroids and to increase public awareness of the risks of asteroid impacts. Asteroids are small, airless rocky worlds leftover from the formation of our solar system about 4.6 billion years ago. Early on, the birth of Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, causing the small objects that were there to collide with each other and fragment into the asteroids seen today. There are millions of asteroids; the large majority of known asteroids orbit in the asteroid belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter (the Jupiter trojans). However, other orbital families exist with significant populations, including the near-Earth asteroids. The asteroid belt (white) and Jupiter's trojan asteroids (green) Trojans share an orbit with a larger planet or moon, but do not collide with it because they orbit in one of the two Lagrangian points of stability L4 and L5, which lie 60° ahead of and behind the larger body. Occasional collisions and gravitational tugs perturb the orbits of asteroids into elliptical ones, some of which cross the orbits of Earth. Such asteroids are known as Near-Earth Asteroids. The JPL Center for NEO Studies (CNEOS) tracks Near-Earth Objects (NEOs) and provides impact probabilities in support of NASA’s Planetary Defense Coordination Office. Various observatories around the world scan the sky for near-earth asteroids and comets. The charts below shows the history of Near-Earth Asteroid (NEA) discoveries per year, by survey and by size. That’s a lot of asteroids whose orbit brings them close to earth. Asteroids smaller than about 25 meters generally burn up as they enter the Earth's atmosphere and cause little or no damage. The Tunguska event (on June 30, 1908) was caused by a stony asteroid estimated to be 50–60 meters wide. The airburst at 6–10 km above the Earth's surface flattened an estimated 80 million trees over an area of 2,150 square km. No impact crater was found. Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the impacted area. Only once every few million years, an object large enough to threaten life on Earth comes along. Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences. According to abundant geological evidence, an asteroid roughly 10 km across hit Earth about 65 million years ago. This impact made a huge explosion and a crater about 180 km across. Debris from the explosion was thrown into the atmosphere, severely altering the climate, and leading to the extinction of roughly 3/4 of species that existed at that time, including the dinosaurs. BTW, an asteroid named 2024 MK flew past Earth on June 29 at a distance of 290,000 km; it was 120 - 260 m in size. See diary It's Asteriod Day 2021. Let's talk and learn about Asteroids, Comets and Planetary Defense for a more detailed look at asteroids, programs to detect them and techniques to defend earth from a potential collision in the future. 433 Eros is a near-Earth asteroid approximately 34.4×11.2×11.2 km Now let’s solve today’s puzzle composed in 1967 by noted Dutch chess composer and Grandmaster Jacobus Haring (1913 - 1989). P.S. The chess puzzle is published on Sundays, Tuesdays and Thursdays at 6:00 p.m. ET. It is customary for advanced players to wait till midnight ET before posting the full solution. Before then, they provide some stats about the solution (e.g., the minimum number of distinct checkmate moves), help guide others, and sometimes post hints. But there are no hard-and-fast rules; feel free to post comments as you please. [END] --- [1] Url: https://www.dailykos.com/stories/2024/7/2/2250421/-White-to-move-and-mate-in-two-530-Asteroid-Day?pm_campaign=front_page&pm_source=more_community&pm_medium=web Published and (C) by Daily Kos Content appears here under this condition or license: Site content may be used for any purpose without permission unless otherwise specified. via Magical.Fish Gopher News Feeds: gopher://magical.fish/1/feeds/news/dailykos/