We live in a day and age where we are are fairly well-versed with our surroundings. By that, I’m talking not just about our immediate surroundings here in earth, but also that of the earth in the solar system. The planets, their satellites, the asteroids and other heavenly bodies in the neighbourhood of our home planet have been well established now.
And yet, not long ago, we were still peering at the skies, discovering new planets and their satellites. William Lassell was one of them, and though he started out as an amateur, he ended up with a notable list of discoveries.
Born in Bolton, Lancashire in 1799, Lasell went on to set up a successful brewing business in Liverpool. It was the high profits from his work that allowed him to turn his attention to other interests. He was drawn towards machinery in general and the construction of reflecting telescopes in particular.
Achieves equatorial mounting
Lassell developed a steam-driven machine to be used for grinding and polishing large mirrors. With these machines, he was able to attain the quality that was then possible only using hand polishing. With the aid of this machine of his own design, Lassell built a 24-inch reflecting telescope.
The interest in telescopes naturally spilled over towards astronomy. Lassell mounted his telescopes on an axis with the ability to move parallel to the Equator. Among the first telescopes to achieve equatorial mounting, it allowed astronomers the flexibility to follow a star through its course throughout the day.
On September 23, 1846, Neptune was first observed at Berlin Observatory. Seventeen days later, on October 10, Lassell used his telescope to discover one of Neptune’s satellites. We now know that the moon that Lassell had discovered, Triton, is the largest of Neptune’s satellites.
Bond with the Bonds
Next up, he turned his attention towards Saturn. And in 1848, he discover Hyperion, one of Saturn’s many moons. Lassell shares this discovery with William Cranch Bond and George Phillips Bond, who made the discovery on the same night.
His connection with the Bonds continued as their works overlapped once again. Lassell made his first sighting of the dark inner ring of Saturn, which he called crepe ring, two years later. Having spent an entire night to confirm his discovery, Lassell then saw an article in the newspaper announcing the Bonds’ discovery of the same phenomenon.
On October 24, 1951, Lassell had further success, this time with Uranus. He discovered Ariel and Umbriel, two of Uranus’ many moons. That took his total of discoveries with respect to planetary satellites to four.
Honours and awards
Despite starting out as an amateur, Lassell went on to become a Fellow of the Royal Astronomical Society (1839) and was awarded the Gold Medal of the Royal Astronomical Society in 1849. He was also elected as a Fellow of the Royal Society in that same year and went on to win their Royal Medal in 1858. And after his death in 1880, his telescope was left to the Royal Observatory in Greenwich.
