Chasing shadows at Jupiter: a livestream telescope observation from the summit of Mauna Kea

A moon of Jupiter, Ganymede and its shadow moves across.
Image of Jupiter and Ganymede with shadow
NASA / JPL / Ian Regan
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This event is free and open to the public for the Royal Astronomical Society's bicentenary celebrations and will take place online in collaboration with the Department Physics and Astronomy at the University of Leicester.

To register to attend this free, public, all-ages online event, please register here:

Register via Evenbrite if you would like to join us on Zoom and want a first-hand connection to asking the scientists questions. Otherwise, we will be live-streaming on YouTube here:


On July 17th 2020, we will be remotely observing the shadow of the Solar System’s largest moon Ganymede as it passes over the face of Jupiter with the assistance of Dr. Tom Stallard and Dr. Henrik Melin, Astronomers from the University of Leicester.  Using computers within the UK, they will link to the Infrared Telescope Facility in Hawaii, observing the effects of the eclipse of Ganymede on Jupiter's upper atmosphere.

Weather permitting, the University of Leicester is to live stream this event with the RAS, between 11am and 4pm BST. During the day, one of our observers will take a break from chasing the shadow of Ganymede to host a Q&A, describing the observation, the science that drives it and what we are seeing within our freshly taken data.  If the weather in Hawaii is poor, we will describe what it is like to be an observer when you can't take any data. The day will also include talks by Prof. Emma Bunce, President of the RAS and Professor of Planetary Plasma Physics at the University of Leicester, whose research is on the magnetospheres of Saturn and Jupiter, as well as RAS librarian Dr Sian Prosser discussing early observations of Jupiter as part of the RAS bicentenary celebrations.

This observation is expected to give us vital new insights into how Jupiter's extreme upper atmosphere changes as the planet rotates from day to night. We have no way to measure the night side from Earth, and the measurement would also be very difficult from the Juno spacecraft, currently in orbit around Jupiter.  Unlike at Earth, where lunar eclipses last only a few minutes, the darkness of Ganymede's shadow will envelop a small part of Jupiter for over an hour – we hope to observe this region for more than three hours, allowing us to see Jupiter's ionosphere in darkness for the first time.

Join us throughout the day to see how our observation is progressing, or at one of the talks or question and answer sessions, where we will attempt to help explain the science and astronomy in action.


On the day the scientists are:

Dr. Tom Stallard 

Dr. Henrik Melin 

Professor Emma Bunce - University of Leicester, Head of School, Physics and Astronomy

Dr. Sian Prosser - RAS Librarian 

Lucinda Offer – RAS Education, Outreach and Bicentenary Events Officer - will be hosting the event. Please contact her at for any enquiries.

Schedule - Friday 17th July 2020

Time for event is 11-4pm


All times are UK

11am - Attendees can tune-in to watch set-up

11:30am - Observe Ganymede move onto limb

12pm - Dr. Stallard can begin discussing the science being done

12:30pm - Session 1: Q&A with Dr. Stallard and Dr. Melin

1pm - Professor Emma Bunce - JUICE mission

1:30pm - Check-in with Dr. Stallard and Dr. Melin

2pm - Dr. Sian Prosser shares RAS collection of Jupiter observations

2:30pm - Check-in with Dr. Stallard and Dr. Melin

2:50pm - Dr. Stallard and Dr. Melin - shadow moves off Jupiter 

3pm - Session 2: Q&A with Dr. Stallard and Dr. Melin

3:30pm End of observation

*There may be an opportunity to view Uranus afterwards until 5pm. 


**Please note that the above schedule should only be used as a rough guide and is subject to change. 

We recommend tuning in early to see it live. It will be recorded and available online afterwards. 

Thank you for your understanding.




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