As astronomers we are always looking for new ways to view the universe beyond Earth. In this issue, read how Juno’s first seven orbits are already changing what we know about Jupiter’s atmosphere, composition, and magnetic field. Find out how machines learn to identify gravitational lenses and types of galaxies — and learn how Big Data from vast sky surveys will change the way professional astronomers do astronomy. Peer into the depths of the Great Orion Nebula and its neighbors through the eyes of an observer’s sketchpad. Understand why magnification does not mean more light or greater contrast for your observations with an in-depth exploration of what exactly surface brightness means for an observer. Spot a fifth magnitude open cluster in Cassiopeia, tour craters named for the Lunar Hall of Fame, and read our test report on a new mini tracker. Enjoy these and other stories in the December 2017 issue of Sky & Telescope.
NASA's Juno mission is revealing that our solar system's largest planet is a fantastic, cyclone-festooned world with a strange interior.
By Fran Bagenal
Machines Learning Astronomy
The new era of artificial intelligence and Big Data is changing how we do astronomy.
By Monica Young
Understanding Surface Brightness
It took a while, but the light bulb finally went on above my head
By Jerry Oltion
The Jewel in the Sword
An observer captures on a sketchpad the stunning details of one of the most wondrous objects in the night sky.
By Howard Banich
Autoguiding with PHD2
This open-source freeware can help you take perfectly tracked astrophotos.
By Jerry Lodriguss
Beyond the Printed Page
Does Dark Energy Change Over Time?
Read the full article about how scientists are considering whether the mysterious “force” accelerating the universe’s expansion changes with time.
Teach Yourself Machine Learning
The upcoming successors of the SDSS will mean a lot of data for astronomers to make sense of. Learn about the tools they will employ to find patterns in the massive influx of information.
Sketching the Great Orion Nebula
In 1659 Christiaan Huygens was first to publish a drawing of M42. Learn how he sketched it and how the author made his sketch of the same nebula, featured in this issue.
Lunar Librations and Phases of the Moon
Librations and other lunar data for December 2017.
ALSO IN THIS ISSUE
A Cornucopia of Celestial Curiosities
The year's end prompts reminiscences of stellar things past.
By Fred Schaaf
Go out early and stay out late to catch the best meteor shower of the year.
By S. N. Johnson-Roehr
Lunar Hall of Fame
Beginning in 1645, obsessed observers drew maps of the Moon's face in ever-greater detail.
By Charles Wood
Look to Cassiopeia for her varied collection of celestial treasure.
By Sue French
Table of Contents
See what else December's issue has to offer.