The Celestial Sphere

by Matthew Johnson

The James Webb Space Telescope is scheduled to launch in December. The concept for the telescope was conceived in 1995, and construction started a decade later. Many of the components have been built using multiple technologies, with the work done by hundreds of engineering corporations in America, Canada and Europe. The honeycomb of 18 beryllium mirrors for the telescope, however, was constructed completely in America.

 The construction of the mirrors began in Utah, in the Topaz and Spor mountains in the western part of the state, the only place in the Western Hemisphere where beryllium is mined. The raw beryllium was sent to Brush-Wellman in Elmore, Ohio, where it was pressed into blanks. At Axsys Technologies, a machining plant in Cullman, Ala., the blanks were shaped to create a triangular pattern of ribs on the backside of each mirror. These which are used to secure each mirror in place and lighten the weight.

The mirrors were then shipped to L3Harris Technologies in Richmond, Calif., where the face of each mirror was ground to fine tolerances and polishing began. The mirrors then went to at Ball Aerospace in Boulder, Colo., where they underwent optical testing. Continued testing was conducted in Alabama, at NASA’s Marshall Space Flight Center in Huntsville, where a cryogenic vacuum chamber was employed to measure the tiny distortions that the mirrors will experience in the deep coldness of space. Then it was back to Ball Aerospace for post-processing of the mirrors.

After this, the mirrors returned to L3Harris Technologies in California, where they received a final polishing, performed to correct for the cryo-distortions found at the Marshall Space Flight Center. The mirrors now needed to be cleaned at Ball Aerospace. After the cleaning, they were off to Quantum Coatings in Moorestown, N.J., where they were coated with a thin veneer of reflective gold. After Ball Aerospace mounted the mirrors and more cryogenic checks were conducted at the Marshall Space Flight Center in Alabama, the finished mirrors were shipped to the NASA’s Goddard Space Flight Center in Greenbelt, Md., where assembly of the telescope began. After preliminary assembly, the scope was sent to NASA’s Johnson Space Center in Houston, Tex., where more cryogenic tests were conducted on the entire telescope. Final assembly took place at Northrop Grumman in Redondo Beach, Calif., where the scope was then attached to the spacecraft that will launch it into space.

Shortly after the Hubble Space Telescope was launched in 1990, it was discovered that its primary mirror had a flaw that affected the quality of the telescope’s images. Such a mistake will not be allowed to happen with the James Webb telescope. 

Planets: 

Mercury offers its best appearance of 2021 at dawn during the last two weeks of October. To view Mercury, one must look to the east one-half hour before sunrise. An unobstructed horizon is necessary, since Mercury always stays very close to the rising or setting sun.

To locate Venus, look low in the southwest at dusk. It is the brightest object in the sky except the sun and moon. With a small telescope, Venus can be seen to enter into phases, waxing and waning, just like our moon. This is because Venus is an inner planet, located between the sun and the Earth.

Mars is too close in its orbit to the sun to be viewed this month. 

Both Jupiter and Saturn glow brightly in the constellation of Capricorn during October. Jupiter is best viewed a few hours into the evening, beginning in late twilight. Any telescope will reveal Jupiter’s atmospheric banding and its four Galilean moons, Io, Europa, Ganymede and Callisto. Saturn, like Jupiter, is best viewed a few hours after sunset all month long. Saturn can be found just to the right of Jupiter. Titan, its largest moon, can be seen with a small telescope to the north of Saturn on Oct. 5 and 21 and to the south of the planet on Oct. 13 and 29.

 The easiest night to locate Jupiter and Saturn is Oct. 14. Look south one hour after sunset. The waxing moon will be located between Jupiter and Saturn. Jupiter will be slightly to the left and above the moon, while Saturn will be above the moon and slightly to the right. While the planet Uranus can occasionally be seen with a larger telescope, Neptune and Pluto are reserved for more professional instruments and experience. 

Meteor showers: 

October’s Orionid meteor shower peaks the night of Oct. 21. The meteors are the result of the Earth’s orbit crossing the regular 76-year path of debris left by Halley’s Comet. Unfortunately, the full moon will occur the night before the 21st, blocking out all but the brightest meteor streaks. 

Moon phases:

Oct. 6: New moon: no visible moon. The best time of the month to observe faint objects such as distant galaxies. 

Oct. 13: First quarter: right half of moon illuminated. Moon is waxing.

Oct. 20: Full moon: Hunter’s Moon.

Oct. 28: Last quarter: left half of the moon illuminated. Moon is waning. 

With cold weather ahead, this month’s luminary is known as the Hunter’s Moon. It signals a time to stock up on game, which has fattened in preparation for winter. 

 The Dakota called October’s full moon the Drying Rice Moon, in honor of the postharvest preparation of rice for winter. The Anishinaabe termed it the Falling Leaves Moon, signaling the transition from fall to winter, and the Cree called it the Migrating Moon, referring to the birds flying south to warmer climates.