If this photograph looks amazing, we’re poised to explore one of the sky’s most stunning sights. It’s the lunar crater Copernicus, which many regard as the Moon’s loveliest object. It’s easy to find if you gaze moonward two or three nights after the first quarter (evening half Moon) phase. It basically sits all by itself to the upper left of the Moon’s center. And though a mere 57 miles in diameter, equal to about four Thruway exits, it displays tons of detail through even the most modest backyard telescope.
Recently taken by the skilled New England amateur astronomer Robert Reeves, this image shows what you can experience from your own backyard. Even better, lunar features dramatically change from night to night as the shadow-line separating day from night creeps along the lunar surface at ten miles an hour. Nowhere else can such a small financial investment yield such a huge aesthetic payoff. On nights when our air is steady — meaning the stars are not twinkling — details like these materialize through any $300, three-inch telescope. Of course, better equipment produces incrementally superior images, and, like boat owners eyeing the larger vessel at the next marina, it can be hard to know when enough is enough. The 14-inch instrument Richard used for this picture cost about $6000. But I could not claim my $24,000 observatory set-up could show you anything better. The point? Get yourself a six- or eight-inch reflector, a three-inch refractor, or an eight-inch Schmidt Cassegrain with a steady tripod and you’ve got a lifetime of exquisite viewing.
Such as decades of gaping at Copernicus. Notice that unlike the other craters in this photograph, its inner walls have steps or terraces that lead down to the shadowed crater floor. The small craters in this image lacks such terraces, a common result when the incoming meteor was too small to carve out a cup larger than 15 or 20 miles. Also notice that some craters have sharp rims while others display rounded edges. The sharp-edged ones are newer so don’t suffer the erosional effects that have gradually made the lunar surface a land of rounded, Catskill-like features. Copernicus was created only 800 million years ago while most lunar craters arose from the “great bombardment” that peppered both the Moon and Earth four billion years ago.
Thus, you can read the Moon like a history book from your own backyard. That’s why it’s so fascinating that I still observe it several times a month even after 50 years. In our age of super telescopes like the James Webb, and mind-twisting celestial objects like quasars and colliding neutron stars, this nearest of all celestial objects visually remains the best of them all.