Astronomy 2018-04.pdf

EARTHCHANGEThe world s best-selling astronomy magazineAPRIL 2018 www.AVol.46 Issue 4Secrets of nightscape photography p.50Have exploding stars altered human evolution?p.44Travel along to see Chiles greatest telescopes p.28 Binoculars made for the night sky p.64 PLUS Springs best and brightest galaxies p.59 EXTINCTION may come from the galaxy s disk p.22COULDMATTERDARK HOWEXCLUSIVEBONUS ONLINE CONTENT CODE p.4At Sky-Watcher USA were ready for the season with four complete lines of award-winning Dobs:traditional,collapsible,GoTo and Stargate truss-tube.With this variety we have something for every taste and budget.From March 1,2018 through March 31,2018,all of our Dobs will be on sale.Dont miss out on some of the best savings of the year!So if youre looking for a big light bucket with a little price tag,Sky-Watcher USA has what you need.2018 Sky-Watcher USA.Specifications subject to change without notice.20-18002.We love it when we can bring big apertures to people for less money.Please take advantage of it!For information on all of our products and services,or to find an authorized Sky-Watcher USA dealer near you,just visit .Dont forget to follow us on Facebook and Twitter!Sky-Watchers complete lines of award-winning traditional,collapsible and Stargate Dobsonians are on sale Regular price Sale price You save6 Traditional Dobsonian.$305.$285.$208 Traditional Dobsonian.$385.$355.$3010 Traditional Dobsonian.$595.$545.$508 Collapsible Dobsonian.$475.$425.$5010 Collapsible Dobsonian.$695.$635.$6012 Collapsible Dobsonian.$1095.$1015.$808 GoTo Collapsible Dobsonian.$1050.$950.$10010 GoTo Collapsible Dobsonian.$1335.$1135.$20012 GoTo Collapsible Dobsonian.$2105.$1880.$22514 GoTo Collapsible Dobsonian.$2555.$2305.$25016 GoTo Collapsible Dobsonian.$3400.$2950.$45018”Stargate.$5999.$5499.$50018”GoTo Stargate.$6999.$6499.$50020”Stargate.$6999.$6499.$50020”GoTo Stargate.$7999.$7499.$500For over 25 years,The Great Courses has brought the world s f oremost educators to mi lli ons who want to go deeper i nto the subj ects that matter most.No exams.No homework.Just a world of knowledge avai lable anyti me,anywhere.Download or stream to your laptop or PC,or use our f ree apps f or i Pad,i Phone,Androi d,Ki ndle Fi re,or Roku.Over 600 courses avai lable at www.TheGreatC.The Higgs Boson and BeyondTaught by Professor Sean CarrollCALIFORNIA INSTITUTE OF TECHNOLOGYLECTURE TITLES1.The Importance of the Higgs Boson2.Quantum Field Theory3.Atoms to Particles4.The Power of Symmetry5.The Higgs Field6.Mass and Energy7.Colliding Particles8.Particle Accelerators and Detectors9.The Large Hadron Collider10.Capturing the Higgs Boson11.Beyond the Standard Model of Particle Physics12.FrontiersHiggs in SpaceThe Higgs Boson and Beyond Course no.1205|12 lectures(30 mi nutes/lecture)Understand This Triumph of Modern PhysicsThe recent discovery of the Higgs boson was celebrated around the world.The quest to pursue it cost 10 billion dollars;involved years of international collaboration among top physicists,engineers,and other experts;and led to the construction of the single largest and most complex device in the history of mankind.And yet,few people truly understand what the Higgs boson is or why it is so significant.In The Higgs Boson and Beyond,award-winning theoretical physicist Sean Carroll,a brilliant researcher as well as a gifted teacher who excels in explaining scientific concepts to the public,leads you through this thrilling story.He clearly explains the necessary background of the basics of quantum mechanics,the Standard Model of particle physics,and more,helping you realize how the discovery of the Higgs boson validates and deepens our understanding of the universe.Off er expires 05/07/18THEGREATCOURSES.COM/4ASTR1-800-832-2412LIMITED TIME OFFERORDER BY MAY 770%offSAVE UP TO$160DVD$199.95 NOW$39.95Video Download$169.95 NOW$24.95CD$134.95 NOW$24.95Audio Download$89.95 NOW$17.95+$5 Shi ppi ng&Processi ng(DVD&CD only)and Li f eti me Sati sf acti on GuaranteePriority Code:156768CONTENTSPicture of the DayGorgeous photos from our readers.News The latest updates from the science and the hobby.Ask Astro Archive Answers to all your cosmic questions.My Science Shop Perfect gifts for your favorite science geeks.4 ASTRONOMY APRIL 201822 COVER STORYDark matter s shadowy effect on Earth Earths periodic passage through the galaxys disk could initiate a series of events that ultimately lead to geological cataclysms and mass extinctions.MICHAEL R.RAMPINO28Sharing the skies above ChileThe Astronomy in Chile Educator Ambassadors Program explores the unique collaboration forged by U.S.astronomy observatories in Chile.ALISON KLESMAN34Ask AstroPlanet or moon?36Sky This MonthMars and Saturn rendezvous.MARTIN RATCLIFFE AND ALISTER LING38StarDome and Path of the PlanetsRICHARD TALCOTT;ILLUSTRATIONS BY ROEN KELLY44How supernovae have affected life A nearby exploding star may affect Earth in ways were just now beginning to understand.ADRIAN L.MELOTT50Secrets of n