Free Astronomy Magazine September-October 2019

Editor in chief Michele Ferrara Scientific advisor Prof. Enrico Maria Corsini Publisher Astro Publishing di Pirlo L. Via Bonomelli, 106 25049 Iseo - BS - ITALY email info@astropublishing.com Internet Service Provider Aruba S.p.A. Via San Clemente, 53 24036 Ponte San Pietro - BG - ITALY Copyright All material in this magazine is, unless otherwise stated, property of Astro Publishing di Pirlo L. or included with permission of its author. Reproduction or retransmission of the materials, in whole or in part, in any manner, with- out the prior written consent of the copyright holder, is a violation of copy- right law. A single copy of the materi- als available through this course may be made, solely for personal, noncom- mercial use. Users may not distribute such copies to others, whether or not in electronic form, whether or not for a charge or other consideration, with- out prior written consent of the copy- right holder of the materials. The publisher makes available itself with having rights for possible not charac- terized iconographic sources. Advertising - Administration Astro Publishing di Pirlo L. Via Bonomelli, 106 25049 Iseo - BS - ITALY email admin@astropublishing.com ASTROFILO l’ September-October 2019 BI-MONTHLY MAGAZINE OF SCIENTIFIC AND TECHNICAL INFORMATION FREELY AVAILABLE THROUGH THE INTERNET English edition of the magazine S U M M A R Y 4 14 20 22 24 K dwarfs, the best target for biosignatures For many years, we have believed that M dwarfs were the ideal stars around which to look for the first signs of extraterrestrial life. Now we have realized that planets in M dwarf habitable zones are subjected to extreme conditions and phenomena for a time incompatible with life as we know it. Researchers... La Silla 50 th anniversary culminates with total solar eclipse At 16:40 CLT, the Moon covered the face of the Sun, in a total solar eclipse visible from a 150-km-wide swathe of northern Chile, including ESO’s La Silla Observatory, which celebrated half a century of astro- nomical research this year. ESO, in collaboration with the Government of Chile, organised an outreach... First 18 ELT primary mirror blanks arrive at Safran Reosc The first set of 18 blanks for the primary mirror of ESO’s Extremely Large Telescope have arrived safely at Safran Reosc in Poitiers, France. The contracts for casting the blanks of the mirror segments, as well as polishing, mounting and testing them, were signed in 2017 with respectively the German company... The Tunguska event, now rarer than expected Every day, over 100 tons of dust and particles of interplanetary sand fall to Earth. At least once a year, a meteoroid as big as a car hits the atmosphere, generates an impressive fireball, and disintegrates before reaching the surface. Every several hundred years, a small asteroid as big as a football field impacts our... NEAR instrument sees first light Breakthrough Watch, the global astronomical program looking for Earth-like planets around nearby stars, and the European Southern Observatory (ESO), Europe’s foremost intergovernmental astronomical organisation, announced “first light” on a newly-built planet-finding instrument at ESO’s Very Large... “Moon forming” circumplanetary disk in a distant star system Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the first-ever observations of a circumplanetary disk, the planet-girding belt of dust and gas that astronomers strongly theorize controls the formation of planets and gives rise to an entire system of moons, like... Space radiation − a deadly obstacle Research on space radiation has expanded rapidly in recent years, but many uncertainties remain in pre- dicting the biological responses of humans to radiation exposure. Future manned space missions will travel far beyond low Earth orbit and away from the protection of the Earth's magnetosphere, where... ESO contributes to protecting Earth from dangerous asteroids The International Asteroid Warning Network (IAWN) coordinated a cross-organisational observing cam- paign of the asteroid 1999 KW 4 as it flew by Earth, reaching a minimum distance of 5.2 million km on 25 May 2019. 1999 KW 4 is about 1.3 km wide, and does not pose any risk to Earth. Since its orbit is... VST captures a celestial gull in flight The main components of the Seagull are three large clouds of gas, the most distinctive being Sharpless 2-296, which forms the “wings”. Spanning about 100 light-years from one wingtip to the other, Sh2-296 displays glowing material and dark dust lanes weaving amid bright stars. It is a beautiful example of... The early days of the Milky Way revealed by Gaia The universe 13 billion years ago was very different from the universe we know today. It is understood that stars were forming at a very rapid rate, forming the first dwarf galaxies, whose mergers gave rise to the more massive present-day galaxies, including our own. However, the exact chain of the events... 34 38 40 50 52