Two developments occurred recently to advance large telescopes and the study of the universe around us.
Scientists in the U.S. completed the first of seven 8.4-metre mirrors for the Giant Magellan Telescope under construction in Chile. Six of the mirrors will be arranged petal-like around the seventh, central mirror.
When construction is finished, the telescope will have four times the light-gathering capacity of instruments used today.
An event closer to the hearts of Victoria astronomers involves the Thirty-Meter Telescope. In November, state officials in Hawaii recommended approval for construction of the telescope on the state’s highest peak, Mauna Kea.
The recommendation is a key step in the long, complicated process required to build atop Hawaii’s volcanoes.
The Thirty-Meter Telescope will feature a light-collecting mirror that is — surprise! — 30 metres across. When it begins operation in 2020, it will be one of the world’s most powerful optical and infrared telescopes.
With telescopes, size matters.
The larger a telescope’s mirror is, the more starlight it collects. The more starlight it collects, the further it sees into space and time. That extra power allows astronomers to glean more information about the universe, permitting both greater scientific understanding and yet more research opportunities.
The University of Victoria and the Herzberg Institute for Astrophysics on Little Saanich Mountain are crucial members of the international consortium of universities and governments working on the Thirty-Meter Telescope. This is, however, only the latest large telescope Victoria has been associated with.
In 1914, construction began on Little Saanich Mountain’s first telescope, an instrument 1.85 metres, or six feet, across. For months after its completion in 1918, this telescope was the largest operating telescope in the world.
I repeat: largest OPERATING telescope.
When the Victoria telescope was being built, the father of American astronomy, George Ellery Hale, was building a 100-inch telescope at Mount Wilson, California. But he was having problems. By insisting on a 100-inch mirror, he was pushing the limits of existing technology and materials. He had trouble obtaining the glass disk that would become the mirror, the First World War slowed work further, and after the mirror was installed in 1917, it was years, according to Hale’s own correspondence, before the telescope worked properly.
Meanwhile, the Victoria group, led by astronomer John Stanley Plaskett, moved ahead with the 1.85-metre project and started observing stars with it on May 6, 1918.
The competition between the two observatories was correctly cordial. Yet some documents from the time hint at unspoken rivalry. And a certain smugness.
Four years later, the Mount Wilson team had resolved their telescope issues and brought in astronomer Edwin Hubble to stargaze. He soon discovered the universe comprises multitudes of galaxies, not one massive starfield, as previously thought.
Meanwhile, Plaskett’s crew had completed data collection and analysis of the oldest, brightest stars to be seen from Victoria, and confirmed the rotation and gravitational centre of the Milky Way galaxy.
By the mid-1930s, Hubble had declared the universe is expanding, and Hale was planning a 200-inch telescope for the desert west of San Diego. Plaskett’s team measured the size, mass and rotation of the Milky Way, and confirmed our location within it. And the Victoria telescope’s design was being replicated in new observatories around the world.
Although the rivalry is long gone and the 1.85-metre mirror has since been replaced with a newer disk, the Plaskett telescope remains in use today. It put Victoria on the scientific map, and enabled a 94-year legacy of groundbreaking research.
I look forward to seeing how local researchers’ work with the Thirty-Meter Telescope adds to the city’s long-standing reputation for cutting-edge astronomy.