Set within the private grounds of Marlborough College is the fabulous Blackett Observatory. It is home to an incredible 10″ Cooke refractor steeped in history that offers stunning views of the Cosmos! Observing is organised by the observatory’s enthusiastic Director, Gavin James.
The observatory is not often open to the public; however, the facility is accessible to those outside the College interested in Astronomy. For example, you can become a ‘Friend of the Marlborough telescope‘, which costs just a few pounds per year, and in return, you will be given access to their stargazing events diary, arrange private visits and attend regular lectures at the College.
Location events organiser
Blackett Observatory organises events at this location
Please contact Blackett Observatory directly with any enquiries relating to visiting this location
Email: [email protected]
Website: Blackett Observatory
Weather forecast
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02/07/26
23° 1% -
02/07/26
23° 1% -
02/07/26
21° 0% -
03/07/26
16° 1%
Weather forecast for Marlborough (0.7 miles away) updated 02/07/26 at 12:01. Powered by Met Office data.
Local light pollution
Blackett Observatory is estimated to have light pollution levels similar to a semi-rural location based on the latest data from the VIIRS satellite. For more advanced light pollution data, view this location on DarkSkySites.
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Dark site
The above demonstrates the estimated effect of light pollution - graphics created using Stellarium.
Best time to visit
The below chart shows when the skies will be at their darkest at this location and therefore the best time to visit. Moonlight is shown in light yellow and the Sun's twilight in light blue. Midnight on the date shown is shown as a white line with sunset to the left and sunrise the next morning to the right. A black background with stars shows the best times for stargazing. See our dark sky calendar for more details.
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Find more dates
If you are planning to visit this location check our dark sky calendar to find out when is best!
CalendarEvents nearby
Stay and gaze nearby
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