Blackett Observatory Dome
Welcome to the Marlborough College Blackett Observatory, home to the largest refracting telescope in Wiltshire. Learn more...
moon phase info

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SpaceWeather | More weather... Coordinates: 51.25.25 N and 1.44.24 W
Marlborough College
Oxford Astrophysics
Green Templeton College

Next Event: Thursday 27th May - Solar H-alpha Observing (14:30 BST)

If the weather is kind and the sky is clear, there will be a live stream of the solar surface from the 10-inch via Zoom. In the event of inclement weather, there will be a Cloudy Alternative. A link for this observing session will be emailed to Friends nearer the day.


Blackett Observatory Radio Meteor Detection System - Live Stream

The radio meteor detection system is now being live streamed 24/7 on this website, scroll down to view...


Unfortunately the Observatory will remain closed to visitors
while social distancing measures are in place

A range of talks and observing sessions will be delivered online instead

NASA Astronomy Picture of the Day

What's Up!

Week of 10th May

  • Astronomical twilight ends at 23:34 BST at the beginning of the week and at 00:02 BST by the end of the week

  • On Thursday, the very thin, 1.8 days old, waxing Crescent Moon will be in conjunction with Mercury (mag +0.1), separated by about 2.5°. Look at around 14° altitude above the west-northwest horizon at about 21:00 BST, after sunset. You will also find Venus (-3.9) lower down, just above the horizon

  • On Sunday, Mercury will reach its highest point in the sky for this apparition, sitting at an altitude of 16° at 21:00 BST

  • The Moon is New on Tuesday

  • The Sun currently has one active region, AR 2822. The sunspot number is 17

  • The ISS makes the following visible evening passes this week:
    Friday: 21:51, SSE to ESE, max 13° and 23:25, SW to E, max 49°
    Saturday: 22:38, SW to E, max 36°
    Sunday: 21:51, SSW to E, max 26° and 23:27, WSW to E, max 78°



Blackett Observatory Radio Meteor Detection System - LIVE STREAM

Press the '>' Play icon to start the Live Stream
You may need to turn up the volume
Best viewed in Full Screen

Random Blackett Image
Past Events - Public Open Evening


5th May

GCSE Solar observing:The Remove astronomers returned t the Dome for an early, Period 1, session. The sky was clear, though it was a little chilly. The Sun had no spots, but with the white light filter and the 10 inch on full apperture, the tiny, 1000km sized, convection cells (granulation) on the photosphere were visible

23rd April

GCSE Solar observing: As part of Topic 10, the Remove Astronomy set of 15 pupils came up to the Dome and were supervised by CEB and GKWJ. The sky was clear and the Sun was observed first in Solar Goggles and then using Solar Scopes. The rotation rate of the Earth was estimated from the projected image. The 2 ETXs were then used with white-light filters to view the photosphere and the 2 sunspot groups were clearly vsisble. The image was as expected clearer at 35x magnification than 70x. The 10 inch was then used with the hydrogen-alpha filter to view the chromosphere and a large, bonfire shaped, prominence seen on the south westerm limb. This was drawn by the students

25th March

MCBO Outreach: GKWJ presented a live guided tour of the Blackett Observatory to a Zoom gathering of 50+ members from the Basingstoke and Newbury Astronomical Societies. The audience heard about the history of the observatory and its main instrument, the Cooke 10-inch. The session concluded with a live-stream view of the waxing Gibbous Moon through the 10-inch, allowing viewers to enjoy impressive detail of the Montes Alpes, Rima Suess, Schickard crater and more

22nd March

Radcliffe Society: Members of the society met online for the March meeting. First, a pupil spoke about his Royal Astronomical Society award winning poster on radio meteor detection. The group then looked back at the three recent missions to Mars, enjoying the Night Sky News video from popular Oxford astrophysicist YouTuber, Dr Becky Smethurst. The session ended with an appraisal of the scientific accuracy of the film 'The Martian'. Next meeting: 24th May

18th March

Sun-Earth Day Lecture: CEB delivered the 2021 NASA/ESA Sun-Earth Day Lecture to a group of Friends, pupils and invited guests via Zoom. The lecture title was 'The 'computer' who unlocked the universe' - a fascinating look at the work of four of the most influential women in the history of astronomy

16th March

GCSE Observing: 10 pupils from the Remove joined GKWJ at the Dome for observing. The session started with a view of the 3 day old crescent Moon in the 10-inch - a marvellous sight! The pupils then made sketches of the southwestern sky, placing Orion carefully with respect to the horizon, meridian and celestial equator. They estimated the right ascension of Betelgeuse, given the local sidereal time and estimated magnitudes of various stars. A most enjoyable return to observing

11th March

GCSE Observing: Members of the Hundred joined GKWJ at the Dome for a long awaited observing session. Conditions were windy with fast moving patchy cloud. Pupils made an observing target list, selecting one of each astronomical object type. Observing started outside with the naked eye, finding: Orion, Orion's Belt, Betelgeuse, The Orion Nebula (M42), The Pleiades (M45) and Mars. The Right Ascension of Betelguese was estimated using the Local Sidereal Time and finding the Meridian. The group moved inside to slew the 10-inch to The Whirlpool Galaxy (M51), but unfortunately thickening cloud brought the session to an end. Irritatingly, the sky cleared some ten minutes later!

2nd March

House visit:7 Shell pupils from PR joined CEB on Zoom for the rearranged Dome visit. This was the last visit this year. Visits will recommence in September (hopefully live)

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