Thursday, 7 May 2020

Hubble and Juno

Mike Wong invited me to be a co-author on his excellent paper in ApJ Supplement, which describes the Hubble and Gemini support programmes for the Juno mission:

Wong, M.H., A.A. Simon, J.W. Tollefson, I. de Pater, M. Barnett, A.I. Hsu, A.W. Stephens, G.S. Orton, S.W. Fleming, C. Goullaud, W. Januszewski, A. Roman, G.L. Bjoraker, S.K. Atreya, A. Adriani, L.N. Fletcher (2020), High-resolution UV/optical/IR imaging of Jupiter in 2016-2019, The Astrophysical Journal Supplement Series, Series, 247, 58 (25 pp.) (

Credit: International Gemini Observatory/NOIRLab/NSF/AURA M.H. Wong (UC Berkeley) and team Acknowledgments: Mahdi Zamani.

Images from both facilities were released to the public and created quite a splash, with the Gemini "lucky imaging" at 5 microns even making the BBC website.  Here is a collection of the media releases:

Hubble Space Telescope
Gemini Observatory

The full dataset is also available via open access on the MAST archive.

Combined data from the Juno spacecraft, the Hubble Space Telescope and the Gemini Observatory reveal a special cloud structure near a massive cluster of lightning flashes: a three-way combination of deep clouds made of water, large convective towers — essentially Jovian cumulonimbus — and clear regions with downwelling, drier air outside the convective towers. (Image courtesy of NASA, ESA, S. Brown of JPL, M.H. Wong of UC Berkeley and A. James and M. Carruthers of STScI)

Wednesday, 6 May 2020

Recording Powerpoint

I've been wrestling with how to record myself delivering Powerpoint slideshows, as research has shown that your audience is more engaged when they can see the speaker.

In Powerpoint for Windows (with a 365 subscription) it seems that you can record both Audio and Video narration while you deliver your slides, but there doesn't appear to be a way to do this in Powerpoint for Macs (and I have the latest versions).

There is a brute-force approach using Zoom (thanks to Anita Heward for pointing this out) - you can start a personal meeting room, turn on your video, and share the screen (or just the Powerpoint window).  The Shift-Cmd-R starts and stops the video recording.  Once the meeting is ended for all participants, the recording is saved as an MP4 in my Movies directory.

Another colleague pointed me towards the free Open Broadcaster Software (OBS) Studio, and this seems to have solved my problem for me with even more control over content.

  1. Download the OBS Studio and install on your Mac.
  2. Upon opening for the first time, allow it to do the automatic configuration (i.e., I just let it set up all the defaults, and specified that I'd be using this for recording, rather than for streaming).
  3. I then added a new "Video Capture" in the Source box at the bottom, allowing it access to my Mac's webcam.  My face turns up in a little box in the OBS window, which I can resize and relocate as I see fit.
  4. I then experimented with adding a simple "Image" in the Source Box, again resizing to whatever dimensions I wanted.  But now came the tricky part - adding Powerpoint.
  5. In Powerpoint, click on "set up slide show" and make sure that "Browsed by an Individual" is checked.  This means that when you start displaying your slides, it will only occupy the window, rather than filling the whole screen.
  6. In OBS, you can then go to "add source", select the Powerpoint window, and resize the window to whatever works best for your presentation (i.e., it might occupy 60% of your screen, leaving room for your webcam).  
  7. If you have the Powerpoint window and the OBS window side by side, you can then advance the slide show easily whilst watching them change in the OBS window.
  8. Click on "Start Recording" and deliver your slide show, clicking on "Stop Recording" when you're done.  My recording was then saved as an MKV file under "Movies" on my Mac (you can change this in settings).  In OBS, go to "File > Remux Recording", choose the file you want to alter, click on "remux", and it'll generate an MP4 version of your MKV file.
  9. If you want to get really snazzy, then OBS has techniques for cutting the start and end (where you'll be fiddling with start/stop recording), and even introducing fades and titles.  But that's probably for the more advanced user.

Health warning - I haven't yet tried to record a full presentation yet, this is only at the experimentation phase...

Monday, 27 April 2020

Virtual Conferences - Part II

The ongoing Coronavirus crisis has pushed several conferences into a hasty virtual version, with varying degrees of success.  As described in my previous post, there are opportunities to be inventive and imaginative, recognising the potential advantages of inclusivity and accessibility, and to offer something that people can participate in across the time zones.  So let's see what's currently on offer.

LPSC 2020 

LPSC was cancelled in early March, without enough time to shift to a virtual format for talks and posters.  Some virtual meetings were offered spanning topics of community interest (the planetary decadal survey, NASA townhalls, etc.), and a series of Virtual Early Career Planetary Networking Events are now underway, consisting of real-time online conferences via 'RingCentral' (3 slides, 5 minutes per presenter) that are hopefully being watched by prospective employers, and can then be shared online.  LPSC have provided hosting for e-posters, as has the Earth and Space Science Open Archive (ESSOAr), which is also used for the AGU.  

Leigh:  Despite the fact that you can then get a DOI for your contribution, there doesn't appear to have been a wide-scale uptake of this approach, as I don't see many papers on the archives.  I'm not sure how many people might actually be downloading and reading them, either, unless it was really close to my research area - it's not like browsing posters and chatting to authors in person.

EGU 2020

EGU (scheduled for early May) had more time to plan, so could be more ambitious. Using the #shareEGU20 hashtag, EGU runs for four days in May and became free to join, although uploads of presentation materials and commenting required authors and participants to have a Copernicus user account.  Abstracts had been submitted before the crisis, and charged a €40 abstract processing fee.  The conference would be entirely through uploaded "displays", comments on the presentations, and real-time text chats (08:30 to 18:00 CEST).  There would be no live presentations in the science sessions, nor video or audio chats.  Union symposia (one per day, 10:45-12:30 CEST), great debates, and some townhall meetings would be hosted through videoconferencing.

For scientific sessions, authors could upload presentations for a month before the meeting, then a dedicated, live, text-based chat for discussion would be held for the presentations of that session.  Presentations could have a variety of formats - PDFs or PPTs of the slides, or even mp4 files to record a video.  The important thing was that the appropriate Creative Commons License be included, and that presentation materials (and potentially comments) would remain online.  This shouldn't make any difference to future publication - most journals specifically allow posting on a (not-for-profit) preprint server prior to submission.  Journals allow, and usually encourage, that authors discuss their work at conferences prior to writing and submitting a manuscript.

Uploads of presentation materials were encouraged from 1 April to 31 May, and the same two-month period is valid for comments by the community and replies by the authors.  Then the May 4-8th session chats are in real time and are time-limited.  EGU opens one text-based chat channel per session linked in the online programme. The link becomes active 15 minutes prior to scheduled session start and disappears 30 minutes after the scheduled end of the session. All chat channels use the software sendbird run on servers of Amazon Web Services (AWS) located in Frankfurt/Main, Germany.  Chats are not recorded and archived. The posts are deleted after the session ends.  The text-based live chat neither involves live presentations, nor video or audio chats, in order to remain inclusive for all attendees.  All orals, posters, and PICO talks were converted to 'displays' that allow those who have submitted abstracts to upload presentation materials, opt in to commenting, and participate in a live text chat during the scheduled session time.

Leigh:  I set up a personal programme for the giant planet sessions, finding a large number of withdrawn abstracts or non-presented materials.  Even so, there were tonnes of talk titles, and I found little to motivate me to download and read each one.  There needs to be a bit of organisation, so that talks are assembled into sub-groups and themes, rather than big long lists of links.  

Those links I clicked on provided the full slide decks, but without someone talking me through the materials, I quickly lost interest.  I'd much rather listen to someone tell me the story, with the central narrative and rationale that you get in a talk, rather than just reading someone's slides.  I clicked through a few titles I was interested in, but there were no comments.  I'm interested to see how the text chats go.

AAS 2020

AAS were due to hold their 236th meeting in Madison in early June, and have switched to a 3-day version of their usual summer conference (slimmed down from 4 days).  The bulk of the meeting will be held in real time, restricted to those who register, and captured for later access by registrants who might have missed something in real time.  Recordings of the plenary talks will be made freely available to all AAS members.  Science sessions will be parallel 90-minute sessions of short talks arranged thematically, with iPoster (digital interactive) contributed posters and iPoster-Plus (presentations featuring short talks illustrated with iPosters), also arranged thematically.  There would still be press conferences, but they decided not to include splinter meetings.

AAS will be using Zoom Webinars (not Zoom Meetings) for science sessions and plenaries. A “host” and a small number of “participants” control the meeting and give the presentations, while the “attendees” (from dozens to hundreds) are not seen, heard, or able to control anything or share their screens. Attendees may ask questions and respond to polls initiated and controlled by the host or participants. I've seen iPosters presented at DPS meetings, where authors use standard templates to create a digital iPoster, which is then available online shortly before, during, and after the conference.  iPosters can include audio narration; high-resolution, zoomable images; videos and animations; and text with (or without) embedded hyperlinks. In addition, iPosters include a "chat" feature that allows someone viewing an iPoster to interact in real time with the author.

Leigh:  I really like the idea of the iPosters, and have seen these in action before.  Having the regular orals delivered realtime via webinars means a substantial inconvenience for anyone in a different time zone, but at least they will be recorded and so could be viewed later (by attendees at least).  Speakers will only be answering questions during the live sessions, but there can be virtual rooms after sessions to continue the conversation.

EAS 2020

The European Astronomical Society Annual Meeting (formerly known as EWASS) was due to be held in Leiden in late June, and has moved to an online meeting using a custom-built platform from their organisers, Kuoni.  It seems that registration fees are being refunded, but that the virtual meeting will charge a reduced fee (€80 for 5 days, €50 for one day).  According to their FAQ page, the meeting will still take place over 5 days, with some elements live, and some pre-recorded.  It looks like they'll also stick to the Central European time zone, just like AAS is sticking to the US time zone, making it a challenge for participants in time zones greatly removed.    For registered participants the presentations (platform and posters) will be made available after the meeting for a limited period of time (TBD).  They are aiming to use interaction options like chat, Q&A and live polling, and there will be ePoster sessions. 

Leigh:  The virtual EAS is still evolving, but also seems to be aiming to use the regular time slot for their meeting, rather than distributing it over a longer time period.  It'll be interesting to see how the real-time and asynchronous aspects of the conference blend together.

**This post is a work-in-progress, please check back!**

Thursday, 23 April 2020

Uranus from Hubble

Tuesday, 21 April 2020

Virtual Conferences - Part I

It's now been 6 weeks since I last stepped foot in my office.  6 weeks of trying to be productive from home, and it feels like a vast swathe of my working time has been spend on virtual meetings via Zoom, Skype, Teams, BlueJeans, Webex.... I've even taken the lead on a few.

They're not great - lots of hours spent in front of my computer (sometimes listening via my mobile phone), often at inconvenient hours because of differences in time zones, and usually wishing the speaker would've just summarised their thoughts in an email.

And now we're facing the prospect of some of the major planetary science conferences moving online, and it's abundantly clear that WE CAN'T EXPECT THIS TO BE BUSINESS AS USUAL.  There has to be a better way for doing this.  Thankfully, this is an issue that's already been considered by much more thoughtful people than me.

Benefits of Virtual Conferences

Here are some of the reasons why virtual conferencing really should become more frequent in the 21st century, even without global health crises preventing travel:
  • Climate, climate, climate:  The carbon footprint of academic departments is usually overwhelmed by researchers travelling across the world for meetings, and its time for a culture change if we're to do our bit.  I think it's fair to admit that some of this travel is unnecessary.
  • Work-life balance: how many weekends have been lost to travel, ready to start a meeting at 9am on a Monday?  Family life disrupted because of the need to start at the beginning of the "working week?"  
  • Inclusivity:  How many members of our community are we missing because of parental and other carer responsibilities?  How many voices are absent because travel poses extreme challenges, financially, physically, or mentally?  Shifting online might open the door to a more inclusive conference.
  • Less time wasted on "marginally-useful" meetings: We all know them - the meetings we felt we had to show our faces at, even though we didn't have a lot to contribute, and didn't learn a lot as a result.  FOMO - fear of missing out - often drives us to attend.  Now we can attend them virtually, and possibly even multi-task to get other things done at the same time.   

Problems with Virtual Conferences

Here are some common problems with virtual meetings, some easier to solve than others:
  • Stifled Discussions:  Virtual conferences are great as a one-way flow of information, either as live talks or pre-recorded presentations.  But new collaborations and ideas often stem from the more informal coffees, lunches, poster sessions, and chance encounters.  These casual "in-person" chats are currently hard (but not impossible) to replicate in the virtual world, and lack the "spontaneity" of people meeting in the same physical location.  There's also the question of the lack of human contact, where in-person conferences might be the highlight for those working in isolation.
  • Multiple time zones:  My work is very Europe/US focussed, meaning lots of late-afternoon and evening meetings.  The idea of running an 8-hour conference day virtually is just a nonsense - no one is working at their best under those circumstances, and I personally struggle to keep my brain going late in the evening.  Not to mention those colleagues trying to follow from the east, in the middle of the night...  so: make one-way information delivery (i.e., talks) available to watch during preferred timezones, and keep discussion meetings for a mutually-convenient (and shorter) time slot.
  • Lost voices:  Raising your hand in a big meeting can sometimes be nerve-wracking.  Doing it online, when you're not sure who is listening, and in the absence of virtual cues to know how they're responding to your question (rolling their eyes, or wide-eyed astonishment), it can be extremely daunting.  We need a way to make all participants comfortable and willing to contribute.
  • Loud voices:  In the same vein, some speakers will dominate the Q&A and discussion,  overwhelming everyone else, and hogging all the precious time.  A strong moderator, able to recognise and involve everyone, is a must for inclusive virtual conferences.
  • Can you hear me now?  I was on mute... You can play conference bingo, with phrases like this on almost every meeting.  The technology is getting better and better, but often relies on the skills of the users - we shouldn't assume that all participants have good microphones, good cameras, quiet environments conducive to chats, sufficient broadband to connect, or know how to share a screen, presentation, or virtual whiteboard.  
  • Promotion and career progression:  Standing on stage and delivering your first conference talk is a tremendously nerve-wracking experience, but can open doors to future jobs and collaborations.  Early-career researchers rely on conference networking for opportunities, mid-career researchers need keynote and invited presentations for promotion, and the virtual world is hard-pushed to deliver this.  UCSB professor Ken Hiltner describes this as "present or perish."
  • The art of presentation:  I've given short lectures via web conference, and they're hard - when I'm in front of an audience, I try to read the energy, knowing when to ramp up enthusiasm to keep people going, or when to go back over a concept because of blank, horrified faces.  You play to the crowd.  You don't get that sat alone at your desk.  But that's a small price to pay.
PS:  Trying to blend virtual conferences and in-person meetings together invariably leads to problems.  It's a nightmare dialling in to a meeting when the room is full of people talking to one another.  Far better to go all-or-nothing, and to have everyone participating remotely so that they're on an equal footing!

Another Way...

Virtual conferences will probably never replicate the face-to-face interactions that we're used to.  However, the COVID-19 crisis is, by necessity, leading to innovation in virtual conferencing, but this is a challenge that was already being considered as part of the nearly carbon-neutral (NCN) conference model.  That helpful guide suggests:
  1. Speakers pre-record their conference presentations for hosting on a conference website (which can be as simple as a Wordpress site) so that they may be viewed at any time (i.e., removing the real-time requirement), giving the viewer time to think and come up with questions.  Pre-recorded videos can also be better-rehearsed and polished, and also closed-captioned (in multiple languages) for greater accessibility.
  2. A shared online Q&A session (organised into themed sub-panels) over 2-3 weeks, with written questions and answers, where the members of a panel respond to audience queries.  Eliminating the "live Q&A" and making them "asynchronous" means that the problem of multiple time zones is removed, and removing the pressure of "on-stage" questions might allow more time to think and develop robust answers.  Breakout sessions on specific themes could also be organised.
  3. Archive of content (talks and Q&A transcripts) after the conference, open access across the globe.  This one I worry about a little - sometimes conference talks are used to present data before publication/peer-review, and authors may be reluctant to risk any (social) media coverage ahead of key publications.  Maybe a "do not cite" or a time-limited shelf life could be incorporated?
I particularly like this paragraph on Hiltner's website: "Such events can result in far more efficient use of a conference goer’s time, as one can quickly scan through the text of a talk or a Q&A session for material of interest. Consequently, this NCN approach allows us to listen to all the talks of interest to us – and none of those that are not – in the order, and at a time, of our choosing"

Hiltner encourages conference organisers to experiment with this scheme, and I personally feel that a blend of pre-recorded talks (sometimes called "asynchronous" content), real-time live discussion ("synchronous"content), and Q&A might be the right combination of flavours, and I hope that our planetary-science conferences (DPS, EPSC, AGU, EGU, LPSC, COSPAR) find a balance.  Tanja de Bie of the Leiden Centre for Innovation also has a handy run-down of remote conference pros, cons, and suggestions. 

And the ACM guide for virtual conferences provides a low-overhead virtual conference:  "First, ask authors to pre-record their talks and upload the videos to YouTube. Link those video from the conference website. This involves very low overhead on the part of the conference organizers, as they do not have to deal with supporting the live presentation of all these talks. Additionally, set up a few synchronous sessions for Q&A with groups of authors and panels using one of the videoconferencing and/or Webinar systems (e.g., Zoom). Consider also setting up a Slack workspace for participants to chat before, during, and after the live sessions. The links to the live sessions can be disseminated in Slack."

In particular for planetary science, there's an opportunity for short, focussed sub-meetings (i.e., a week-long meeting on one topic), eliminating the nightmare of overlapping parallel sessions that plague the major meetings.  Why be constrained to a single week?  Why not have the conference over a month, spreading out the themes?  I think you still need to make it "an event" over a limited time period, so it doesn't just feel like a series of talks on a website.  Provided everyone is in the same boat, why not have regional hubs, so some people could meet in person to watch presentations and hold panels?

In Part II of this post, I'll try to look at some examples of virtual conferences being held in 2020, to explore the pros and cons....


Friday, 20 March 2020


This week has been a long year.

It's Friday March 20th 2020, and if the world had been anywhere close to normal, I would have been hurtling down a white water rapid with old friends on a stag party today, before enjoying a night out on the town.  But like a hundred million other social engagements, that's all been brought to an earth-shattering halt by a global public health crisis.

Last Sunday I started to experience griping stomach pains, which I initially put down to some dodgy food the night before (I'd been foolishly left in charge of the cooking).  But by that evening, I was unable to get warm, sat shivering in a dressing gown on the sofa whilst the kids got prepped for the school week ahead.  A blue lump of clammy awfulness.  Fever raged all night, and I knew I had a problem the next morning - headaches, chills like ice, and moments of intense heat and dehydration.  I'd been expected in the office to examine 3rd-year physics projects Monday afternoon, and it has to be damned serious for me to let people down.  But that's what I had to do, sending a series of apologetic cancellation emails Monday morning (including to my fellow stag party members), before collapsing on the sofa that afternoon.

Monday evening, the UK brought in new guidance requiring all household members to self-isolate for 14 days, if even one person shows any symptoms of COVID-19, including high fever and a continuous new cough.  My kids were disappointed to be missing their school friends - my daughter especially so, as she'd been practising for the school production.  Soon enough though, that too was cancelled.  So from Tuesday, the four of us were in self-isolation for two weeks.

The fever lasted through Monday night and into Tuesday, probably around 36 hours in total.  When it finally broke, I tried to get some work done, but the griping stomach pains continued into the next day too, doubling me over in pain.  I spoke to the NHS 111 line (who essentially read me everything I'd already read online, but couldn't advise any further), who put me onto a GP for reassurance and recommended some over-the-counter medication, which some kind neighbours picked up for us and left at our door.  These helped, but by Wednesday afternoon the illness provided a second sting, as the fever returned with a vengeance - and once again I was in bed with high temperature and dehydration.  Now 72 hours in.

Thankfully the fever had broken by Thursday morning, and the stomach pains greatly diminished.  I'm left with a mild dry cough and a strange sensation of being an asthmatic, with slightly troubled breathing, particularly when climbing stairs.  All this for a reasonably healthy 38-year-old.

Now, all this sounds suspiciously like the symptoms of COVID-19 to me.  I rarely get colds, I don't remember the last time I ever had flu-like symptoms, and I find the chances of it happening during the same week as a global pandemic escalation all a little suspicious.  But clearly not impossible.  So, for overseas readers, you might be wondering why I don't just get tested?  That's because the lacklustre and (some might say) irresponsible responses of the UK government has been not to test the wider population, focussing only on hospitals.  Not only does this mean that the numbers of infections you've been reading about are nonsense, but also that it's going to be near-impossible to track the spread of this disease.  Plus, it means I can't know whether I'm now immune, nor whether my family are all self-isolating for no reason.  In short: the UK needs to step up its testing as a matter of urgency.

If it is COVID-19, where might I have caught this from?  Up until Tuesday 10th March I'd been working from the office, commuting to work every day by train, and interacting with the students.  I started home working on the Wednesday out of an abundance of caution, but I'm so glad I did, as it limited my contact during the potential 5 days of being asymptomatic, before my fever started on Sunday.  One superb reason why people should be taking the social distancing guidelines seriously.

A lot has changed in a week - schools all closed yesterday.  University of Leicester brought forward end of term to today.  I've had all future meetings cancelled or postponed.  Weddings put off to future, happier times.  My diary is empty.  They've ordered all the pubs closed.  My wife is a key worker, so I'm facing the prospect of home schooling for at least part of each week for months to come, meaning productivity will drop to somewhere near zero.  But all of these are nothing compared to what some are about to go through.  I've been touched by the kindness and generosity of our friends and family while we've been self-isolating - we'll all need so much more of this if we're to cope with the dark times ahead.

And finally, permit me to be blunt and angry for a moment:  to the cretins and morons who are selfishly stockpiling or flouting the guidelines on social distancing, stop.  Just stop.  Your stupidity could have catastrophic consequences for all of us, and particularly the most vulnerable in our society.  I hope your victims have the opportunity to forgive you.

Good luck everyone, stay healthy, and stay kind.

Wednesday, 26 February 2020

Examining Ice Giants With NASA’s Webb Telescope

From a NASA/Goddard press release on February 26th 2020, covering our Guaranteed Time Observations of Uranus and Neptune:

Credits: NASA, ESA, and M. Showalter (SETI Institute); Right: NASA, ESA, L. Sromovsky and P. Fry (U. Wisconsin), H. Hammel (Space Science Institute), and K. Rages (SETI Institute)

Far-flung Uranus and Neptune — the ice giants of our solar system — are as mysterious as they are distant. Soon after its launch in 2021, NASA’s James Webb Space Telescope will change that by unlocking secrets of the atmospheres of both planets.

The cold and remote giant planets Uranus and Neptune are nicknamed the “ice giants” because their interiors are compositionally different from Jupiter and Saturn, which are richer in hydrogen and helium, and are known as the “gas giants.” The ice giants are also much smaller than their gaseous cousins, being intermediate in size between terrestrial planets and the gas giants.  They represent the least-explored category of planet in our solar system.  Scientists using Webb plan to study the circulation patterns, chemistry and weather of Uranus and Neptune in a way only Webb can.

“The key thing that Webb can do that is very, very difficult to accomplish from any other facility is map their atmospheric temperature and chemical structure,” explained the studies’ leader, Leigh Fletcher, an associate professor of planetary science at the University of Leicester in the United Kingdom. “We think that the weather and climate of the ice giants are going to have a fundamentally different character compared to the gas giants. That’s partly because they’re so far away from the Sun, they’re smaller in size and rotate faster on their axes, but also because the blend of gases and the amount of atmospheric mixing is very different compared with Jupiter and Saturn.”

All the gases in the upper atmospheres of Uranus and Neptune have unique chemical fingerprints that Webb can detect. Crucially, Webb can distinguish one chemical from another.  If these chemicals are being produced by sunlight interacting with the atmosphere, or if they’re being redistributed from place to place by large-scale circulation patterns, Webb will be able to see that.

These studies will be conducted through a Guaranteed Time Observations (GTO) program of the solar system led by Heidi Hammel, a planetary scientist and Webb Interdisciplinary Scientist. She is also Vice President for Science at the Association of Universities for Research in Astronomy (AURA) in Washington, D.C. Hammel’s program will demonstrate the capabilities of Webb for observing solar system objects and exercise some of Webb’s specific techniques for objects that are bright and/or are moving in the sky.

Uranus: The Tilted Planet

Unlike the other planets in our solar system, Uranus — along with its rings and moons — is tipped on its side, rotating at roughly a 90-degree angle from the plane of its orbit. This makes the planet appear to roll like a ball around the Sun. That weird orientation — which may be the result of a gargantuan collision with another massive protoplanet early in the formation of the solar system — gives rise to extreme seasons on Uranus.

When NASA’s Voyager 2 spacecraft flew by Uranus in 1986, one pole was pointing directly at the Sun.  “No matter how much Uranus would spin,” Hammel explained, “one half was in complete sunlight all the time, and the other half was in total darkness. It’s the craziest thing you can imagine.”

Disappointingly, Voyager 2 saw only a billiard-ball smooth planet covered in haze, with only a scant handful of clouds. But when Hubble viewed Uranus in the early 2000s, the planet had traveled a quarter of the way around in its orbit. Now the equator was pointed at the Sun, and the entire planet was illuminated over the course of a Uranian day.

“Theory told us nothing would change,” said Hammel, “But the reality was that Uranus started sprouting up all kinds of bright clouds, and a dark spot was discovered by Hubble. The clouds seemed to be changing dramatically in response to the immediate change in sunlight as the planet traveled around the Sun.”

As the planet continues its slow orbital trek, it will point its other pole at the Sun in 2028.

Webb will give insight into the powerful seasonal forces driving the formation of its clouds and weather, and how this is changing with time. It will help determine how energy flows and is transported through the Uranian atmosphere. Scientists want to watch Uranus throughout Webb’s life, to build up a timeline of how the atmosphere responds to the extreme seasons. That will help them understand why this planet’s atmosphere seems to go through periods of intense activity punctuated by moments of calm.

Neptune: A World of Supersonic Winds

Neptune is a dark, cold world, yet it is whipped by supersonic winds that can reach up 1,500 miles per hour. More than 30 times as far from the Sun as Earth, Neptune is the only planet in our solar system not visible to the naked eye. Its existence was predicted by mathematics before its discovery in 1846. In 2011, Neptune completed its first 165-year orbit since its discovery.

Like Uranus, this ice giant’s very deep atmosphere is made of a thick soup of water, ammonia, hydrogen sulfide and methane over an unknown and inaccessible interior. The accessible upper layers of the atmosphere are made of hydrogen, helium and methane. As with Uranus, the methane gives Neptune its blue color, but some still-mysterious atmospheric chemistry makes Neptune’s blue a bit more striking than that of Uranus.

“It’s the same question here: How does energy flow and how is it transported through a planetary atmosphere?” explained Fletcher. “But in this case, unlike Uranus, the planet has a strong internal heat source. That heat source generates some of the most powerful winds and the most short-lived atmospheric vortices and cloud features of anywhere in the solar system. If we look at Neptune from night to night, its face is always shifting and changing as these clouds are stretched and pulled and manipulated by the underlying wind field.”

Following the 1989 Voyager 2 flyby of Neptune, scientists discovered a bright, hot vortex — a storm — at the planet’s south pole. Because the temperature there is higher than everywhere else in the atmosphere, this region is likely associated with some unique chemistry. Webb’s sensitivity will allow scientists to understand the unusual chemical environment within that polar vortex.

Just the Beginning

Fletcher advises to be prepared for seeing phenomena on Uranus and Neptune that are totally unlike what we’ve witnessed in the past. “Webb really has the capability to see the ice giants in a whole new light.  But to understand the continual atmospheric processes that are shaping these giant planets, you really need more than just a couple of samples,” he said. “So we compare Jupiter to Saturn to Uranus to Neptune, and by that, we build up a wider picture of how atmospheres work in general. This is the beginning of understanding how these worlds are changing with time.”

Hammel added, “We now know of hundreds of exoplanets — planets around other stars — of the size of our local ice giants. Uranus and Neptune provide us ground truth for studies of these newly discovered worlds.”

The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

For more information about Webb, visit

Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.

Ann Jenkins / Christine Pulliam
Space Telescope Science Institute, Baltimore
410-338-4488 / 410-338-4366 /

Last Updated: Feb. 26, 2020
Editor: Rob Garner