On this date 140 years ago, American physician and prominent amateur astronomer Henry Draper (1837-1882) made the first successful photograph of the Great Nebula in Orion, now usually referred to as the Orion Nebula. He used an 11-inch telescope (an Alvan Clark refractor!) and an exposure time of 50 minutes for the black and white photograph.
Draper continued to improve his technique, and a year and a half later he obtained a 137-minute exposure showing much more detail.
It really is amazing how image recording technology has improved over the past century and a half! At its best, film-based photography had a quantum efficiency of only about 2%, which means that only 2 out of every 100 photons of light impinging on the photographic medium is actually recorded. The rest is reflected or absorbed. The human eye—when well dark adapted—has a quantum efficiency of 15% or better, easily besting photography. Why, then, do photographs of deep sky objects show so much more detail than what can be seen through the eyepiece? The explanation is that the human eye can integrate photons and hold an image for only about 0.1 second. Film, on the other hand, can hold an image much longer. Even with reciprocity failure, photographic media like film can collect photons for minutes or even hours, giving them a big advantage over the human eye. But charge-coupled devices (CCDs) are a considerable improvement over older technologies since they typically have a quantum efficiency of 70% up to 90% or more. The CCD has truly revolutionized both professional and amateur astronomy in recent decades.
Fifty years ago this day, the Soviet Union’s Luna 16 robotic probe made a night landing in the Sea of Fertility. It drilled nearly 14 inches into the lunar regolith, collected 3.6 ounces of soil, and delivered its precious cargo to Earth four days later.
The astronauts on Apollo 11, 12, 14, 15, 16, and 17 between 1969 and 1972 brought back a total of 840 lbs of moon rocks and soil. Each successive Apollo mission brought back a larger amount of lunar material.
The Soviets brought back a total of 0.7 lbs of lunar soil through their robotic sample return missions Luna 16 (1970), Luna 20 (1972), and Luna 24 (1976).
So, excluding lunar meteorites that have befallen the Earth, a total of 840.7 lbs of lunar material has been brought to research laboratories here on Earth.
After a hiatus of over 44 years, China plans to launch two lunar sample return missions, Chang’e 5 in November 2020 and Chang’e 6 in 2023 or 2024. Chang’e 5 is expected to return at least 4.4 lbs of lunar material from nearly 7 ft. below the surface at its landing site in the Mons Rümker region of Oceanus Procellarum.
Chang’e is the Chinese goddess of the Moon, and is pronounced chong-EE.
Recently, I wrote about the extraordinary orchestral music of 20th-century Spanish composer Joaquín Rodrigo (1901-1999). In that piece, I lauded a collection of Rodrigo’s orchestral work, all conducted by the esteemed Mexican conductor Enrique Bátiz with three different orchestras. Today, I would like to share with you the best and most complete recordings of Rodrigo’s piano music, a two-disc set by Gregory Allen and Anton Nel (two piano and piano four hands works).
I wish other music CDs had as much detail about each of the pieces as the enclosed booklet by Gregory Allen and Linton Powell has, nicely indexed by CD track in the margins of the narrative. They write: “The present recordings represent the first complete collection of Rodrigo’s original piano music for two and four hands, omitting only a few transcriptions and lost early works.” In a footnote, they detail the works that are excluded. I am familiar with only one of these, the Cinco piezas del siglo XVI of 1937, which is worth seeking out.
At the end of the documentary Shadows and Light, made when Rodrigo was 90, there is a spellbinding performance of Zarabanda lejana (Distant Sarabande) of 1926. I’m pretty sure the recording they used was the one on these discs. The tempo and sensitivity of this performance is perfect. I have another recording that seems rushed by comparison, and it ruins the mood.
Here we have 2 hours and 33 minutes of delightful piano music composed by Joaquín Rodrigo, sure to increase your appreciation for this great 20th-century composer. Of course, I have a number of favorites.
Zarabanda lejana (Distant Sarabande)
Cinco piezas infantiles (Five children’s pieces), for two pianos
Sonatina para dos Muñecas (Sonatina for two Puppets), for piano four hands
Gran Marcha de los Subsecretarios (Grand March of the Subsecretaries), for piano four hands
Atardecer (Dusk), for piano four hands
À l’ombre de Torre Bermeja (In the Shadow of the Crimson Tower)
Plegaria de la Infanta de Castilla (Prayer of the Princess of Castile), from Cuatro piezas para piano
If you need any more convincing that this recording is a “must have”, here are words written by Joaquín Rodrigo himself.
“Gregory Allen’s recording of my works for piano is excellent. His magnificent technique and his authentically fine interpretation satisfy me completely.”