The Royal Observatory’s Great Equatorial Telescope

If you’re a lover of space, science, or historic instruments, the Royal Observatory Greenwich in London offers an unmissable opportunity to explore one of the most remarkable telescopes ever built—the Great Equatorial Telescope. Located at the heart of the Royal Observatory, this awe-inspiring piece of equipment has played a pivotal role in the field of astronomy for over a century, and it continues to captivate visitors with its history and functionality.

Let’s take a closer look at why this incredible telescope and its home, the Royal Observatory, should be at the top of your list when visiting London.

The Great Equatorial Telescope: A Historic Marvel

The Great Equatorial Telescope at the Royal Observatory is a 28-inch refracting telescope, the largest of its kind in the UK. Built by the Grubb Telescope Company in Dublin, the telescope was installed in 1893 and was originally designed for astrophotography. It soon became a crucial tool for the Royal Observatory’s research, particularly in the study of double stars, expanding our understanding of these celestial objects.

This telescope, with its iconic onion dome roof, remains an enduring symbol of astronomical exploration. While the telescope was mainly used for research in the past, it still functions today and provides visitors with a glimpse of the technological marvel that has shaped space exploration for over a century.

How Does the Great Equatorial Telescope Work?

Unlike other telescopes at the Royal Observatory, the Great Equatorial Telescope is designed to rotate east to west, allowing astronomers to track the movement of stars across the sky. This unique feature is what gives the telescope its name—“equatorial,” meaning it moves parallel to the equator, aligning it with the Earth’s axis.

The telescope’s 28-inch wide lens collects starlight, which is then focused down to the eyepiece for astronomers to observe. The telescope was originally used to measure double stars, helping astronomers determine the mass of distant stars by tracking their changing angles and separation. Over time, it has played a significant role in cataloging more than 150,000 double stars.

A Rich History of Astrophysics

The Great Equatorial Telescope was integral to keeping Britain at the forefront of astrophysics during the late 19th and early 20th centuries. Under the guidance of Royal Astronomers, the telescope contributed to expanding our knowledge of the universe. It was instrumental in measuring and cataloging stars, including some of the most important celestial discoveries of the time.

The telescope also survived significant setbacks, including World War II, when the onion dome was destroyed by a flying bomb in 1944. However, the telescope was safely dismantled and stored during the war. After the war, it continued to serve the Royal Observatory at Herstmonceux Castle in Sussex before being returned to Greenwich in 1971.

See the Telescope in Action

Today, the Great Equatorial Telescope is still operational and plays an important role in public outreach and education. Visitors to the Royal Observatory can experience this historic instrument firsthand. During the winter months, the Observatory hosts astronomy sessions, where visitors can get a close look at the telescope in action. The telescope now benefits from a computer-aided guidance system and CCD cameras, which help astronomers guide the telescope’s movements and enhance its observational capabilities.

The public can also enjoy audio-visual presentations that demonstrate the telescope’s power and showcase its long history. These sessions give visitors a chance to witness the remarkable capabilities of a telescope that’s over a century old, while also learning about the history of astrophysics.

The Royal Observatory: More Than Just the Great Equatorial Telescope

The Royal Observatory Greenwich is home to much more than just the Great Equatorial Telescope. Visitors can explore the Prime Meridian of the World, where they can stand with one foot in the Eastern Hemisphere and the other in the Western Hemisphere. The Observatory is also where Greenwich Mean Time (GMT) was established, and it remains the site for global timekeeping.

Additionally, the Royal Observatory features fascinating exhibits on the history of astronomy, astrophotography, and space exploration, making it a must-visit for anyone with an interest in science and history. The Altazimuth Pavilion, home to the Annie Maunder Astrographic Telescope, is another area worth exploring.

Why You Should Visit the Royal Observatory

The Royal Observatory in Greenwich offers visitors an unparalleled opportunity to explore both history and modern science. Whether you’re an astronomy enthusiast, a history buff, or simply curious about how humanity has explored the stars, there is something for everyone.

The Great Equatorial Telescope remains a key highlight, offering a glimpse into the golden age of astronomical research. The audio-visual presentations, interactive exhibits, and the opportunity to see the telescope in action make this a truly unique experience for visitors of all ages.

The Royal Observatory also offers a range of activities, including educational programs for schools, special events, and even the chance to attend live astronomy sessions. Whether you’re visiting as part of a family outing, a group tour, or as an individual, there’s plenty to explore and learn.

Plan Your Visit

The Royal Observatory is open to the public and offers tickets for entry to the Observatory, the Great Equatorial Telescope, and other exhibitions. Tickets are included in the entry fee to the Observatory, and members can enjoy free admission.

Practical Information:

• Location:
  Royal Observatory Greenwich,
  Blackheath Avenue,
  Greenwich, London SE10 8XJ
• Opening Hours:
  Daily from 10:00 AM – 5:00 PM
• Ticket Prices:
  • Adults: £16
  • Concessions: £14
  • Children (Under 16): £7
  • Family tickets: Available at discounted rates
• Contact Information:
  • Phone: +44 20 8312 6608
  • Email: info@rmg.co.uk
  • Website: Royal Observatory Greenwich