Happy to be here — Standing on new shores
Published 11:41 am Sunday, September 4, 2022
Here in Virginia, the opening years of the seventeenth century are probably best remembered for the arrival of the Susan Constant, Godspeed, and Discovery. The ships made landfall in 1607. The colonists they carried scouted along the unfamiliar coast and eventually chose the location we know today as Jamestown. They did not know how their adventure would unfold.
At the same time during those first few years of the 1600s, astronomers were discovering new facts about the heavens and also gazing on unfamiliar vistas. Johannes Kepler, published studies of planetary motion, observed a supernova, and provided data on a comet that eventually came to be known as Halley’s Comet. The biggest advance, however, may have centered around the arrival of new technology: the telescope.
The first telescope was developed in the Netherlands in 1608. It featured a glass lens to collect light and an eyepiece to deliver a magnified view. Arguably, the most famous person to point such a telescope toward the night sky was Galileo Galilei. With a device boasting a magnification of about 30 times, Galileo viewed mountains and craters on the moon, spotted Jupiter’s four largest moons, and noted the phases of Venus.
Since those days, advances in telescopic design have enabled people to explore deeper and deeper into the heavens. Isaac Newton developed a reflecting telescope that relied on mirrors to gather and focus light, an innovation that facilitated the development of telescopes with bigger apertures. Two and a half centuries later in 1924, using a 100-inch reflector, the Hooker Telescope at Mount Wilson Observatory in California, Edwin Hubble made observations that demonstrated the existence of galaxies beyond our own Milky Way. A few years later, he discovered that the universe was expanding and measured its expansion rate.
These first telescopes, identified as optical telescopes, gathered visible light, which is only a small part of the electromagnetic spectrum. Other instruments followed that could collect longer wavelengths associated with the infrared, microwave, and radio parts of the spectrum, as well as shorter wavelengths in the ultraviolet, x-ray, and even gamma-ray ranges. The space age created an opportunity to put telescopes in orbit where they could avoid the effects of light being blocked or distorted by Earth’s atmosphere.
One of the most famous of these orbiting telescopes is the Hubble Space Telescope, named in honor of Edwin Hubble. Launched in 1990, this telescope sits in orbit approximately 340 miles above the earth and has the ability to view light at ultraviolet, visible, and near-infrared wavelengths. Its primary mirror measures 7.9 feet across. Hubble may be best known for its unprecedented, spectacular images of celestial objects near and far, but it also has played a significant role in advancing our understanding of the universe. Some of its achievements include gathering data about planet formation processes, identifying characteristics of black holes, and discovering the existence of dark energy.
A more recent addition to the telescope lineup is the James Webb Space Telescope. A NASA-led partnership, which includes the European and Canadian space agencies, launched the mission last December on Christmas Day. The JWST was placed in orbit around the sun at a distance of about a million miles from the earth. For comparison, the moon orbits the earth at a distance of about 250,000 miles.
The JWST builds on Hubble’s achievements. Its primary mirror, comprised of 18-gold-plated hexagonal segments that give it a honeycomb-like appearance, measures 21.3 feet across. Its instruments are designed to complement and extend Hubble’s range by collecting light in near infrared and mid infrared wavelengths. According to NASA, the JWST will be able to see objects that are 10 to 100 times fainter than Hubble. The first data and images were received in July.
By gathering such light from our own celestial neighborhood and from the farthest reaches of the visible universe, JWST will help scientists look for the oldest galaxies, study how galaxies change through time, investigate the lifecycle of stars, look for planets that orbit other stars, and examine atmospheres and other physical properties of planetary systems. As scientists seek to better understand our place in the cosmos, humanity once again finds itself standing on new shores. Our adventure continues.
Karen Bellenir has been writing for The Farmville Herald since 2009. Her book, Happy to Be Here: A Transplant Takes Root in Farmville, Virginia features a compilation of her columns. It is available from PierPress.com. You can contact Karen at kbellenir@PierPress.com.