What's the maximum number of planets that could orbit the sun?

Mysteries of Stephen Hawking's doodle-filled blackboard may finally be solved | 430-year-old ninja weapons possibly identified | Ancient surgical implant or modern-day fake? Peru skull leaves mystery. Created for {EMAIL} | [Web Version]( February 14, 2022 CONNECT WITH LIVESCIENCE  [Facebook]( [Twitter](  [LIVESCIENCE]( [LIVESCIENCE]( Amazing science every day [SIGN UP]( ⋅ [WEBSITE](  [] Top Science News [] [Mysteries of Stephen Hawking's doodle-filled blackboard may finally be solved]( [Mysteries of Stephen Hawking's doodle-filled blackboard may finally be solved]( (Isidora Bojovic/Science Museum Group) A new museum exhibit hopes to uncover the secrets behind the doodles, in-jokes and coded messages on a blackboard that legendary physicist Stephen Hawking kept untouched for more than 35 years. The blackboard dates from 1980, when Hawking joined fellow physicists at a conference on superspace and supergravity at the University of Cambridge in the U.K., according to The Guardian. While attempting to come up with a cosmological "theory of everything" — a set of equations that would combine the rules of general relativity and quantum mechanics — Hawking's colleagues used the blackboard as a welcome distraction, filling it with a mishmash of half-finished equations, perplexing puns and inscrutable doodles. Full Story: [Live Science]( (2/13) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] History & Archaeology [] [430-year-old ninja weapons possibly identified]( [430-year-old ninja weapons possibly identified]( (Pictures From History/Universal Images Group via Getty Images) Artifacts found in Japan may be ninja weapons, including several that look like they were the forerunner to the well-known throwing star, have been found at several sites, including two castles, scientists say. Archaeologists excavated the artifacts between 1960 and 2010 at several Japan sites, including two castles — Iwatsuki Castle and Hachioji Castle. The possible ninja artifacts date to the Siege of Odawara which took place in 1590. During this siege, the Toyotomi and Tokugawa clans defeated the Hojo clan, which had controlled a sizable portion of Japan, and captured both castles. Full Story: [Live Science]( (2/14) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] [Ancient surgical implant or modern-day fake? Peru skull leaves mystery.]( [Ancient surgical implant or modern-day fake? Peru skull leaves mystery.]( (Photo courtesy of the Museum of Osteology) An elongated, cone-shaped skull with a possible metal implant could represent some of the earliest evidence from Peru of an ancient surgical implant. Or it could be a modern-day fake. The fact that the skull, which was donated to the Museum of Osteology in Oklahoma City, has a cone shape is nothing too unusual, as Peruvians during ancient times were known to squeeze children's heads with bands during development to achieve the distinctive shape. Full Story: [Live Science]( (2/14) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] Life’s Little Mysteries [] [Why do cats and dogs rub their butts on the floor?]( [Why do cats and dogs rub their butts on the floor?]( (harpazo_hope via Getty Images) Dogs and cats are cute, playful, lovable… and extremely gross. Besides eating poop and licking their butts, one of the most bizarre things these pets can do is rub their rumps on the floor. But why do dogs and cats do this "butt scooting?" Pets rub their butts on the floor simply because it's the easiest way to itch them, said José Arce, president of the American Veterinary Medical Association. Just like humans, pets sometimes get itches on random parts of their bodies. And when a pet's butt is itchy, dragging it across the floor is the easiest way to scratch it. Full Story: [Live Science]( (2/13) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] [What's the maximum number of planets that could orbit the sun?]( [What's the maximum number of planets that could orbit the sun?]( (Shutterstock) The solar system contains eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, all of which circle the sun due to its intense gravitational pull. But is this the maximum number of planets that can orbit the sun? Or is there room for more? Compared with other known planetary systems, the solar system contains an unusually high number of planets. In total, there are 812 known planetary systems with three or more confirmed planets, and only one other known system, Kepler-90, that contains as many planets as the solar system, according to The Extrasolar Planets Encyclopaedia. There is a good chance that a lot of these systems have small inner planets that we cannot detect, so it is unlikely that the solar system is actually the most populated planetary system in our cosmic neighborhood. But it highlights that eight planets may be near the upper limit of how large a planetary system can naturally grow. Full Story: [Live Science]( (2/12) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] That’s Strange! [] [5 million shipwrecked Legos still washing up 25 years after falling overboard]( [5 million shipwrecked Legos still washing up 25 years after falling overboard]( (A.J.B. Lane) A once-in-a-century wave that pummeled a cargo ship in 1997 caused the worst toy-related environmental disaster of all time. As the vessel Tokio Express pitched and rolled near the United Kingdom's southwestern coast, 62 shipping containers tumbled off the ship — and one of them dumped nearly 5 million plastic Lego pieces into the ocean. Soon after the event, which some referred to as the Great Lego Spill, beachgoers in Cornwall, U.K., began finding brightly-colored plastic Legos. Even now, 25 years after the Feb. 13 disaster, numerous Legos from the spill still appear on beaches in Cornwall. Full Story: [Live Science]( (2/12) [LinkedIn]( [Twitter]( [Facebook]( [Email]( [] Daily Quiz [] POLL QUESTION: Theoretically, how many moon-size planets could orbit the sun? (Learn the answer [here]() [Vote]( [No more than 25]( [Vote]( [About 2,400]( [Vote]( [About 11,000]( [Vote]( [More than 65,000](   [Sign Up]( | [Update Profile]( | [Unsubscribe]( [Privacy Policy]( | [Cookies Policy]( | [Terms and Conditions]( CONTACT US: [FEEDBACK](mailto:livescience@smartbrief.com) | [ADVERTISE]( Future US LLC © 1100 13th St. NW, Suite 1000, Washington, DC 20005