Astronomy

JunoCam image North Visible light Depth below cloud tops 0 km 20 km 50 km 90 km 150 km 350 km Cooler Warmer Microwave ASTRONEWS ...

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Time (million years ago) (^0050100150200250300) 0.1 0.2 0.3 0.4 0.5 0.6 Crater formation rate (number/million years ago) 11.6 Ex ...

Time (million years ago) 11.6 36 66 36 66 91 121 145 167 201 228 94 118 145 168 201 225 252 Popigai, Chesapeake Chicxulub Morokw ...

Time (million years ago) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 MAJOR IMPACTS FLOOD-BASALT ERUPTIONSFLOOD-BASALT ERUP ...

WWW.ASTRONOMY.COM 27 of pressure in the upper mantle would result in large-scale melting. This would lead to the production of m ...

28 ASTRONOMY • APRIL 2018 C CHILE IS HOME TO SOME of the world’s best skies — and some of the world’s most advanced instruments ...

WWW.ASTRONOMY.COM 29 and Chile. Each year, the program selects nine ambassadors, and the ACEAP team — and family — grows. Past a ...

Atacama Desert Santiago PACIFIC OCEAN Calama La Serena Valparaíso Copiapó An de s^ M ou nt ai ns ALMA Observatory SOUTH AMERICA ...

WWW.ASTRONOMY.COM 31 World-class observatories We spent two nights at CTIO, touring the observatory by day and forgoing sleep to ...

32 ASTRONOMY • APRIL 2018 required to build and operate a telescope array in such an extreme environment. Astronomical community ...

WWW.ASTRONOMY.COM 33 about outreach goals, some spanning con- tinents to include returning to Chile for future outreach. Among t ...

34 ASTRONOMY • APRIL 2018 A: This is a question that comes up again and again, but as it turns out, there isn’t a clear definiti ...

WWW.ASTRONOMY.COM 35 spacecraft show that the total mass loss rate from Io is about 2,200 pounds (1,000 kilograms) per second. A ...

April 2, 5 A.M. Looking south-southeast SCORPIUS AQUILA OPHIUCHUS SAGITTARIUS Mars Altair Saturn Antares 10° Red and ringed plan ...

AQUILA DRACO HERCULES OPHIUCHUS LY R A CYGNUS April 22, 2 A.M. Looking east Vega Deneb Altair Radiant 10° Lyrid meteor shower WW ...

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PATHOF THE PLANETS The planets in the sky These illustrations show the size, phase, and orientation of each planet and the two b ...