Kelly Beatty
NEWS by Kelly Beatty

Sky & Telescope's New Moon Globe

Introducing the first entirely new globe of the Moon's surface in more than 40 years.

I've always been fascinated with cartography, and I've got a particular soft spot for globes. I love 'em all: Earths with raised relief or now-obsolete borders, celestial spheres old and new, globes of Mars and Venus. When I was very young I had a glow-in-the-dark Moon globe that doubled as a coin bank. I've even made myself a crude set of four spheres portraying Jupiter's Galilean satellites.

Arrival of <i>S&T</i> Moon globe
Joel Toner holds the newly arrived Moon globe, as (from left) Gregg Dinderman, Alan MacRobert, Robert Naeye, and Sean Walker look it over.
S&T: Dennis di Cicco
So you can imagine my joy when, last week, the first samples of the new Sky & Telescope Moon globe arrived. With a diameter of 12 inches (30 cm), it's the standard size for most others these days. In fact, Replogle Globes has been making and marketing a lunar likeness for more than 40 years. Then why, you might ask, was another one needed?

For one thing, the Replogle version doesn't show the real Moon. Instead, it's an airbrushed map derived from the U.S. Air Force's Lunar Astronautical Charts. Chances are you've never heard of these — that's because they were created during the 1960s in support of NASA's nascent lunar-exploration program.

Lunar globes compared
The Sky & Telescope Moon globe (left) compared to the a widely used version created during the 1960s.
S&T: Dennis di Cicco
Make no mistake: the LAC series was meticulously compiled and executed. But Replogle's adaptation doesn't look anything like what you'd see in the eyepiece — there's little distinction between the dark lunar maria and the brighter highlands, for example.

That old globe, while serviceable, just wasn't satisfying. So for years I've been prowling around for a suitable database of lunar photos to make a new one. The Clementine orbiter, launched in 1994, got pole-to-pole coverage, but its images lacked enough resolution and snap. Then came Japan's highly successful Kaguya spacecraft, which orbited from 2007 to 2009, but its images had issues with coverage and lighting angles.

Eventually, the Lunar Reconnaissance Orbiter Camera, launched aboard a NASA spacecraft in 2009, made this new Moon globe possible. You're probably familiar with LROC's high-resolution views of the Apollo landing sites. But it's the camera's wide-angle channel that really caught my attention, as evidenced by this half-gigabyte portrayal of the lunar near-side.

The pieces finally started coming together about a year ago. Mark Robinson, leader of the LROC team, told me the instrument was just completing a global mapping effort with 100-m resolution. The final mosaic consisted of more than 15,000 images acquired between November 2009 and February 2011, with the Sun shining on the surface at incidence angles between 55° and 70° at the equator, lighting favorable for identifying surface features. Several months of back-and-forth ensued to deal with small gaps and imaging artifacts.

To make a smooth globe, the images taken by NASA's Lunar Reconnaissance Orbiter had to be morphed into these two "daisy" projections, one for each hemisphere.
Trent Hare / USGS
Cartographic specialist Trent Hare of the U.S. Geological Survey helped get the LROC data into the right projection — a daisy-shaped image — that would be used to make each hemisphere.

Meanwhile, imaging editor Sean Walker had been perusing the LROC images and likewise came to the conclusion that the time was right for a next-gen lunar globe — one with exquisite, magnifying-glass detail. Joel Toner, Sky & Telescope's publisher, gave the green light for the project to proceed. From the get-go, we wanted something that looked like the Moon (which, in reality, is quite dark) and yet could be labeled clearly with feature labels. So, once we had the two "daisies," it fell to Walker's imaging wizardry to tweak the balance and contrast for both realism and usefulness.

Aarrgh — those #&@$%# labels! How were we going to decide what would be identified and what wouldn't? I started with the USGS's master list of lunar features and selected all the craters with a diameter of at least 75 km (on the near side) and 85 km (on the far side). Then I grabbed the names of every dark feature — all the lunar real estate called mare, lacus, sinus, or palus — along with lots of well-known smaller craters, rilles, peaks, valleys, and spacecraft landing sites. Walker, along with editors Alan MacRobert, Tony Flanders, and Robert Naeye, added even more "must have" features — a collection that kept getting longer and longer.

<i>Sky & Telescope</i>'s Moon globe
Sky & Telescope's Moon globe has more than 850 named features and spacecraft landing sites on the lunar near and far sides. It also comes with an explanatory sheet.
S&T: Dennis di Cicco
By the time we were done, the list had grown to 850 names! The task of adding those to the daisies fell to Gregg Dinderman. Placing them accurately on maps that would eventually be sliced, diced, and glued onto a round ball was a tedious, frustrating Adobe Illustrator marathon. Thank you, Gregg! And we fussed a lot with those labels, checking and rechecking every one. ("Is the correct spelling Tsander or Zander?" "Bel’kovich or Belkovich?" "Fitzgerald or FitzGerald?")

I'm thrilled with (and very proud of) the final result — the first entirely new globe of the lunar surface in more than 40 years. It's emblematic of Sky & Telescope continuing efforts to produce astronomical products that are accurate, timely, and useful. I hope you get a chance to see one soon, and I'd welcome your feedback.

By the way, this might not be the only lunar globe that gets produced from LRO data. For example, the LROC original is so detailed that making a globe 32 inches across — the largest in Replogle's repertoire — isn't completely wacky. But I'll save that story for a future posting.

Posted by Kelly Beatty, April 9, 2012
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First comments (from 12)

Globes

Posted by John Sheff April 9, 2012 At 10:10 AM PDT
Hi, Kelly, It's great to hear about new globes. Do you know whether there is an updated Mars globe in the works? The one I have (from S&T) is based on Viking orbiter imagery 35 years old, and a lot has happened on Mars since then. And, since you mention it, I have long wanted to have globes of the Galilean moons of Jupiter, as well as Mercury. Do you know of any plans to produce those? Thanks, - John Sheff


Moon Globe to scale with 12 inch earth globe

Posted by Nick Dvoracek April 9, 2012 At 02:13 PM PDT
I always thought it would be cool to make a moon globe about 3.25 inches in diameter so it would be in scale with a 12 inch earth globe.


Moon Map Globe

Posted by George Stonebreaker April 9, 2012 At 05:35 PM PDT
What a great globe, and how cool it is to have been in New Symrna Beach Florida when the LRO was launched. I watched it go and I have been keeping up with it ever since. I have been Moon Watching for years and I never tire of our closest neighbor. Even on partly cloudy nights if there is a moon you have something to enjoy and you can spend hours looking at and trying to pick out the different targets and it is a great way to interest new people to the ranks of Amateur Astronomy, if you can throw in a couple of planets they are hooked. Keep up the good work S&T, you've got my support. When can we expect a globe we can purchase? I can't wait to get my hands on one. Clear Skies and keep looking up.


Buying a Moon Globe

Posted by Kelly Beatty April 10, 2012 At 05:59 AM PDT
George... I guess I was downplaying the fact that this globe is now available. You can purchase one by going here: http://www.shopatsky.com/product/moon-globe/new-arrivals


Equator

Posted by Jeff April 10, 2012 At 07:38 PM PDT
The one thing that really bugs me is the large seam around the equator.


re: Equator

Posted by Kelly Beatty April 11, 2012 At 04:16 AM PDT
Jeff... that seam is common to all Replogle globes. after the maps are applied to the two cardboard hemispheres, they are joined at the equator (matched by hand, in fact). the tape covers the line where they meet. check out this video about the process: http://www.youtube.com/watch?v=qgErv6M19yY


how about a new Moon map?

Posted by Grant Miller April 13, 2012 At 06:04 PM PDT
Nice globe! And probably worth the $99. But how about a new more moderately priced($25?) Moon map for use at the telescope. It should be laminated or printed on "plastic" like the DeepMap 600. The LRO images used for the globe should be ideal for a detailed map.


Earth

Posted by Kevin Conod April 13, 2012 At 07:49 PM PDT
@Nick: on the contrary - I would like to see this Moon globe paired with a 44 inch diameter Earth globe!


New Moon Globe

Posted by Gary Linford April 14, 2012 At 02:25 PM PDT
Nice Work! Our 1969 NASA-Apollo 12” Rand McNally lunar globe has been in our library for many years, with the 12” S&T Mars globe and a 12” Replogle Earth globe. It depicts the lava-flooded maria well, but on eBay, the new S&T Moon globe costs much less. Don’t forget--the lunar surface area of 38,000,000 square km is comparable with North and South America put together. The MIT library had a 48” plaster Earth globe but wasn’t that interesting given that 72% of the Earth is blank, covered with water.


New Moon

Posted by Phyllis Dwyer April 16, 2012 At 06:03 AM PDT
Yay! Globes!


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