With the chaos of social media (mainly Twitter) at the end of 2022, I started to experiment with Substack as a forum for posting news and blog posts. I’m not too sure yet, but this blog may be discontinued and relocated.
So if it looks like I’ve vanished from cyberspace, do check out leighfletcher.substack.com
Over the past few weeks I've answered several media enquiries about the future of Ice Giant exploration - here was one exchange by email with Metro News.
Q: Why is Uranus called one of the most intriguing bodies in the solar system?
Uranus is known as an Ice Giant, sitting in between its larger Gas Giant cousins (Jupiter and Saturn), and the smaller terrestrial worlds. When we look out at the ever-growing collection of extrasolar planets (worlds beyond our Solar System), we find that planets of similar sizes to Uranus and Neptune are commonplace. We might therefore have two great examples of the most common outcome of the planetary formation process, right here in our Solar System, and yet their composition, their nature, and their origins remain a mystery.
Uranus is also a world of extremes – tipped onto its side by a catastrophic collision in the distant past, the planet’s atmosphere, magnetosphere, satellites and rings experience the strangest seasons of anywhere in our Solar System. And because we’ve only had a robotic spacecraft visit Uranus once, there are places on those icy moons that no eyes have ever seen – who knows what might be there, waiting for us.
Q: Why wasn’t it explored, so far?
The great distance to Uranus presents an enormous challenge for planetary exploration. Although it has been explored by a single flyby (the Voyager 2 mission in 1986), we need to be in orbit to fully explore the planet, its satellites and rings, over long periods of time. Not only does it take a long time (8-13 years) to get there, but we also need enough fuel to slow us down to enter orbit, and then enough to conduct a comprehensive tour of the Ice Giant system. If we use Jupiter gravity assists, slingshotting by Jupiter on the way to Uranus, we can get more mass (spacecraft, fuel, and scientific payload) into the Uranian system, but that opportunity only comes once every 12-13 years, when Jupiter is in the right place. With the recent announcement from the US decadal survey, I hope that international agencies (NASA, ESA, and others) will be ready for the next opportunity in the early 2030s, so there’s no time to lose.
There’s also the challenge of providing power to a spacecraft at such great distance – the weak sunlight isn’t going to help, so we have to reply on the decay of radioisotope power sources to provide the electrical energy, and those fuel sources need to be robust enough to survive a multi-decade mission.
Q: How a mission to the seventh planet could change the way we see the solar system?
A mission of exploration to Uranus touches on themes of exploration that span not just our system, but planetary systems in general. Namely, we’ll be using Uranus as a window onto the distant past, searching for clues to the puzzle of planetary origins, and how worlds of this size appear to be a common outcome of the planet formation process. Secondly, we’ll be studying a diverse collection of ‘ocean worlds,’ icy moons of Uranus that show signs of ancient geophysical activity and might harbour subsurface oceans. Where there’s water, we might be able to extend the reaches of the ‘habitable zone’ of a planetary system, further out into the frigid realms of the outer solar system than we ever thought possible.
Q: What discoveries do you expect if the mission to Uranus takes place?
The most exciting discoveries will be the ones we haven’t even dreamt of yet. I’m excited to see the interior structure of an Ice Giant, with potentially unimaginable quantities of water in an exotic phase of matter (slushy hot ice) locked away at great depths, and maybe signatures of that ancient cataclysmic impact. I’m looking forward to seeing a probe descending under parachute into the Uranian clouds, sampling the gases and aerosols as it falls. And there are terrains on the northern hemispheres of the moons that no eyes, human or robotic, have ever seen, because they were in total winter darkness when Voyager 2 flew past in 1986 – who knows what we’ll discover there?
Q: What is needed to place Uranus at the top of the space exploration agenda?
Let’s be clear – it is already top of the scientific agenda, as a result of the prioritisation from the US decadal survey in 2022, as a flagship-class mission that engages the entire community of planetary scientists. Its themes span the realms of heliophysics and astrophysics too, and the idea of an Ice Giant mission has broad support from the international community, most noticeably ESA through it’s Voyage 2050 strategic plan. What’s needed now is funding (i.e., increases in existing budgets), both in the US and across the world, to support this ambitious mission on a time frame that works to meet the next launch opportunities in the early 2030s. That’s the biggest challenge that the Uranus mission now faces.
Q: What to expect in the future regarding Uranus exploration?
The coming years will be a race to move this mission from a concept to reality, funding and building the hardware that will eventually sit atop a rocket faring, waiting to launch to Uranus. It will be a long journey of a decade or more, just to reach the launch pad. Then a launch around 2031, slingshot past Jupiter, to arrive in the mid-2040s. If all goes well, the mission will then orbit Uranus for several years, returning a suite of spectacular discoveries just like the Cassini mission to Saturn and the Juno and Galileo missions to Jupiter.
Q: What other celestial bodies have to be urgently explored and why?
In planetary science, we learn more by comparison than by single-target missions. Our exploration and understanding of Ice Giants will remain incomplete until both Uranus and Neptune have been comprehensively explored. Neptune is just out of reach in the coming decade, but the next opportunity for a gravity slingshot arrived at the end of the 2030s. A voyage to Neptune, and its incredible moon Triton (a captured dwarf planet from the distant Kuiper Belt), will be an incredible next step beyond the Uranus mission.
The US Decadal Survey for Planetary Science dropped today, prioritising Uranus for a flagship mission in the coming decade. I had the opportunity to talk to a number of reporters, some of the frequent questions are included below.
Here's the news from the National Academies on #PlanetaryDecadal and #Uranus: when I first read that recommendation, I feared I might be dreaming! Elation, relief, gratitude to the team that made this happen, and a little trepidation about the road ahead. https://t.co/rPVLRedgkL pic.twitter.com/Xq3cj6xzvi
— Leigh Fletcher (@LeighFletcher) April 19, 2022
What does it mean to you to have such a top recommendation for an ice-giant mission?
When I first read that recommendation, I feared I might be dreaming! Elation, relief, pride in the team that made this happen, and a little trepidation about the road ahead. Today we’re one step closer to seeing that ambitious orbital mission to an Ice Giant system that we’ve been working towards for so long.
I owe my career to the pioneers who pushed for the Cassini-Huygens mission to Saturn and Titan, and there’ll be hundreds of future scientists out there today who’ll now get the same chance, making their own discoveries in the Uranian System. I started thinking about Ice Giant exploration in 2008, ahead of the last decadal survey that ranked Uranus as a third priority after Mars and Europa. We’ve been carrying that torch – through research, white papers, mission proposals, and international meetings – on and off for 15 years (including the 2020 Royal Society meeting in London, just before the pandemic hit). The science case has only improved with time, particularly as Ice-Giant-sized worlds (or just smaller) appear commonplace in the pantheon of exoplanets. This decadal survey prioritisation is a wonderful leap forward for the outer solar system community.
When would you think, realistically, a Uranus mission would launch if NASA takes the decadal's recommendation?
There are many hurdles to come – political, financial, technical – so we’re under no illusion. However, missions to Ice Giants are dramatically improved, in terms of the mass that you can deliver to orbit around the planet, if you can borrow some of Jupiter’s energy for a gravitational slingshot. For that, Jupiter has to be in just the right place, which it will be in the early 2030s – the earliest possible slot is 2031 for a 13-year cruise to Uranus, with flexible launch opportunities for a few years after with longer cruises. That gives us around a decade to go from a paper mission to hardware in a launch faring, so there’s no time to lose.
In your opinion, is Neptune entirely off the table for a mission in the near future, given the decadal's concerns about launch options?
The case for a Neptune mission remains as strong as ever, particularly given the high interest in studying Triton as a captured KBO. Indeed, we’d learn far more about the nature of Ice Giant systems via a true comparative study. But it comes down to opportunities: a Jupiter gravity assist for Neptune is available at the end of the 2020s, a little too close for comfort for developing a flagship orbiter and probe. Whilst other trajectories exist without a Jupiter flyby, they’re not without risk and cost, and the decadal suggests that new studies of technology development for a Neptune mission are needed. The next gravity-assist window for Neptune might be under consideration for the 7th New Frontiers mission sometime in the late-2030s/early-2040s, but it’s hard to predict the state of play that far in advance.
And how might a NASA Uranus mission mesh with European contributions, given that an ESA contribution to an international mission to the ice giants was noted in the recent Voyage 2050 exercise from Europe?
I was heartened to see the Voyage-2050 recommendation of an Ice Giant mission with international partners – the same message was given in 2013 when we proposed Ice Giants as a destination for ESA’s L-class missions, and the ESA Director of Science used Ice Giants as an example of what could be done with an ESA funding uplift back in 2019. The key question now is whether there’s room in national budgets and ESA’s science programme for an ambitious partnership – I hope so, but we’ll have to wait and see! After all, the Cassini-Huygens partnership, with its clean separation of tasks and responsibilities, was cited as “a superb example of international cooperation” in this survey.
Obviously by totality I mean "maximum eclipse of about 23% from Leicester", but I was quite excited to capture this image, in any case!
Gotcha! #SolarEclipse captured through the clouds from #Leicester, a few minutes after totality. pic.twitter.com/WsiW8uslE5
— Leigh Fletcher (@LeighFletcher) June 10, 2021
And here are some helpful tools for eclipse safety, and identifying the time and date of the next one:
Partial #SolarEclipse happening tomorrow morning, and visible from here in the UK (23% coverage from Leicester) - with lots of precautions, of course, see safety tips here: https://t.co/69cJz0NBt9
— Leigh Fletcher (@LeighFletcher) June 9, 2021
View for your city here:https://t.co/qrTZqOzQSr pic.twitter.com/ZAUu7P9y2D
I've been asked a few times about space resources available online for primary education, so I'm going to try to collate a list here - this is non-exhaustive, so please feel free to offer suggestions!
The European Space Agency have a range of activities for different key stages:
https://www.stem.org.uk/esero/resources
https://discoverydiaries.org/resources/
Some of my colleagues also helped to provide videos for the STEMLearning Youtube channel, in case that provides ideas:
https://www.youtube.com/c/STEMLearning
There’s a competition on right now to design artwork for the side of the rocket launching JUICE, a Jupiter mission I’ve been working on for the past decade:
https://www.esa.int/kids/en/learn/Our_Universe/JUICE/Juice_Up_Your_Rocket!_art_competition
Some ideas for Space Resources for KS2:
https://www.ogdentrust.com/about-us/news/bringing-deep-space-to-the-primary-classroom
https://www.greatscienceshare.org/weekly-themes-2021-week-2
Destination Space, funded by UKSA:
Week 1 of 2021 - Introduction
Locked down again and going mad. I'm not particularly good at sticking to an exercise routine - seem to get bored too easily with running (after a couch-to-5km) and cycling (which I tend to do with the kids). But I do enjoy walking, whatever the weather, headphones in and listening to an audiobook or podcast. Anyone that lives near me will probably spot me doing laps of the village every few days - we have an old railway line near our home that's a good straight line for several kilometres, some good cross-field footpaths with views towards Leicester city centre, and a nearby hill looking down into a quarry. But with the lockdowns and homeworking of 2020, I've done these loops around the villages many times.... so I wondered about a change and a new challenge. Not that there's anything I can do right now, in the middle of #Lockdown3.
One of the amazing audiobooks I listened to in 2020 was Bill Bryson's Road to Little Dribbling, which saw him taking the route from Bognor Regis to Cape Wrath, a straight-line route that spans England and Scotland (the longest straight line one can travel in the UK without crossing any part of the sea, which he calls the Bryson Line). If you draw a straight line between the two (916 km), it passes within 2.8 km of the very centre of England.
That's right here in Leicestershire, at Lindley Hall Farm, 1.5 km east of Fenny Drayton and 5 km north of Nuneaton. The farm is part of the former RAF Lindley (1943-46) airfield, named after the farm which itself was named after the former Lindley Hall. According to Wikipedia, a plaque denoting this point, and disputing England's "traditional" centre as being Meriden in the West Midlands, was erected by Ordnance Survey on 14 June 2013. This also right next to MIRA, the Motor Industry Research Association, an automotive engineering and development consultancy company that uses the old airfield.
It's also only 7.3 km from where I grew up, in Hinckley in Leicestershire.
So that feels like a meaningful-enough starting point for this fairly pointless blog post. Armed with Strava recording my movements, Google Maps as a guide to the Bryson Line from Lindley Hall Farm, and Wikipedia for place names, I wondered how far I would get without actually leaving Leicestershire.
Week 2 12.69 km (12.69 km so far)
Embarking on the Bryson Line from the dead centre of England. Past Sibson, ending up in a field between Sheepy Magna and Wellsborough at 52.62015, -1.49456. I'm in the civil parish of Sheepy, created in 1935 from the merger of the four civil parishes of Sheepy Magna, Sheepy Parva, Sibson and Upton. Right through the centre of Twycross, home to the incredible Zoo that I've visited many times with my family, and which has the largest collection of monkeys and apes in the Western World. Still in Leicestershire for now. I end up outside a place called the Upper Rectory Farm Cottages in Appleby Magna, which (according to Wikipedia) lies on the edge of the ancient boundary between the kingdom of Mercia and the Danelaw.
Week 3 18.9 km (31.59 km so far)
Appleby Magna to Shortheath, near to the Forestry Commission's Hicks Lodge (good for cycling) and Conkers, in the middle of the National Forest (200 square miles of north Leicestershire, south Derbyshire and southeast Staffordshire planted in an attempt to blend ancient woodlands together into a new forest). Also passed close to Moira Furnace, a nineteenth-century iron-making blast furnace. The Leicestershire county line follows the Hooborough Brook here, so I guess I've officially left Leicestershire and arrived in Derbyshire. Properly passing into Derbyshire now, and heading for the centre of Swadlingcote, still within the National Forest. According to Wikipedia, shallow valleys and ridges, shaped particularly by the mining activity which once dominated the area as the Leicestershire and South Derbyshire Coalfield, seams from the Upper Carboniferous age.
Week 4 28.47 km (60.06 km so far)
Week 5 23.56 km (83.62 km so far)
Week 6 30.66 km (114.28 km so far)
Passed about 3 km west of Mam Tor, and ended near a place called Brown Knoll (about 540m up) on the way to Kinder Scout. Mam Tor is a 517 m hill near Castleton, on the southern edge of the Dark Peak (sandstones) and overlooks the White Peak (limestones). Brown Knoll is one of the highest hills in the Peak District at 569 m, above the head of the Edale valley. It's now the end of January, and I've made it 92.6 km in total, and I'm about 25 km west of Sheffield. From Brown Knoll, just south of Kinder Scout near Edale, north over Torside Reservoir, Yeoman Hay Reservoir, and finishing on the Holmfirth Road, at the very northern edge of the Peak District, the region known as the Dark Peak.
Week 7 31.36 km (145.64 km so far)
Leaving the Peak District, crossing the M62 between Huddersfield and Rochdale, passing 4 km west of Hebden Bridge and Hardcastle Crags (Pennine valley in West Yorkshire), and finishing on Boulsworth Hill, a large expanse of moorland, the highest point of the South Pennines of south-eastern Lancashire.
Week 8 26.55 km (172.19 km so far)
From Boulsworth Hill, continuing to the west of Skipton, and entering the Yorkshire Dales National Park. Finished near Malham Cove, a curved limestone formation in North Yorkshire.
Week 9 50.71 km (222.9 km so far)
Continuing over the Yorkshire Dales from Malham Moor, through North Yorkshire, past the Ribblehead Viaduct, and finishing near the Great Asby Scar Nature Reserve, a limestone pavement in Cumbria. After Leicestershire, Derbyshire, Yorkshire, and Lancashire, Cumbria will be the last English county on this trip.
Week 10 23.52 km (246.42 km so far)
From Asby we leave the Yorkshire Dales behind, skirting up the western edge of the North Pennines AONB (second largest of the 49 AONBs in the UK), crossing the River Eden and finishing near the village of Blencarn, a Cumbria village about 6 km west of Cross Fell (highest mountain in the Pennines, 893 m). Now a few km east of Penrith on the eastern edge of the Lake District, but this route never quite takes me into the Lakes.
Week 11 27.27 km (273.69 km so far)
Skirting the western edge of the North Pennines AONB, just leaving the area to finish near Talkin Tarn, about 14 km east of Carlisle. Talkin Tarn is a glacial lake and country park near Brampton, Cumbria. Passed through Geltsdale, and its RSPB reserve.
Week 12 28.5 km (302.19 km so far)
After 300 km, I'm finally passing over the England-Scotland border near Kershopefoot, a small hamlet in Cumbria at the western edge of Kielder Forest Park, the largest human-made woodland in England. Here the border follows the loops of Liddel Water. Liddel Water's source is beneath Peel Fell in Roxburghshire, in the Scottish Borders, and flows into the River Esk at Willow Pool. Finished near the village of Ettleton. Ettleton is a village in the Scottish Borders area of Scotland, in the former Roxburghshire. Here at the border, I'm about 30 km east of the Solway Coast AONB, but 87 km west of Berwick-upon-Tweed.
 |
| Route from the Scottish Borders to Edinburgh. |
Week 13 32.90 km (335.09 km so far)
First week properly in Scotland, walking from Ettleton, via Teviothead on the A7 (Carlisle to Edinburgh), skirting the eastern edge of Craik Forest (a forest near Hawick in the Scottish Borders area), and finishing a kilometre west of Hellmoor Loch. This is the Scottish Uplands, southernmost and least populous of mainland Scotland's three major geographic areas (the others being the Central Lowlands and the Highlands).
Week 14 22.53 km (357.62 km so far)
Continuing through the Scottish Uplands, across Ettrick Water, Yarrow Water, and finishing very close to the River Tweed in the Cardrona Forest on the A72. The Tweed flows 97 miles through the Scottish Border regions into the North Sea at Berwick.
Week 15 27.73 km (385.35 km so far)
Onwards through the Tweed Valley Forest Park, past Portmore Reservoir near Westloch. Leaving the Southern Uplands to enter the Central Lowlands. Through Penicuik (a town in Midlothian on the west bank of the River North Esk) and into the Pentland Hills Regional Park, to finish near Capelaw Hill. The Pentland Hills run southwest from Edinburgh, so I'm on the outskirts of the Scottish capital now, and apparently there are great views of the city from this hill.
Week 16 26.12 km (411.47 km so far)
Departing the Pentland Hills, and descending through the suburbs of Edinburgh, here I hit a problem. The only bit of this route crossing water, hitting the Firth of Forth just west of the Cramond Causeway, and east of the Forth Bridge, the 130-year old symbol of Scotland. After a swim, back on land near Dalgety Bay. Now in Fife, and continuing east of Dumfermline, before finishing on a hill just west of the Hill of Beath.
Week 17 31.3 km (442.77 km so far)
Travelling northwards through a country of locks, passing just west of Loch Leven (the largest lowland loch in Scotland) near Kinross. Just over the River Earn, finishing just southwest of Perth on the River Tay, the historic county town of Perthshire. I'll be in the County of Perth for quite some time
Week 18 27.17 km (469.94 km so far)
From near to Perth, heading towards the centre of the County of Perth, loosely following the path of the River Tay, and into the Tay Forest Park, just to the west of the Hermitage, Dunkeld, a National Trust of Scotland site. Now properly into the Highlands.
Week 19 24.77 km (494.71 km so far)
Continuing through the Highlands and Tay Forest Park, over the Rivers Tay and Tummel (east of Loch Tummel), through Killiecrankie, ending on a hill east of Croftmore. This is just inside of the Cairngorms National Park, which was already the largest national park in the UK, when in 2010 it was expanded into Perth and Kinross.
Week 20 24.48 km (519.19 km so far)
Looks like a challenging hike through the Cairngorms National Park, finishing about 20km west of Ben Macdui (1309 m), the second highest mountain in Scotland (and all of the British Isles) after Ben Nevis, and the highest in the Cairngorms. The mountains are in the eastern Highlands, a high plateaux at about 1000–1200 m above sea level, above which domed summits rise to around 1300 m.Ten kilometres right into the heart of Inverness, where the River Ness meets the Moray Firth. It's the largest city and the cultural capital of the Scottish Highlands. Then getting my feet wet as I cross Beauly Firth just west of Kessock Bridge, and finally Cromarty Firth just to the east of Cromarty Bridge, making landfall at Drummond. I'm now on the final 115 km of my journey through the Highlands to Cape Wrath.
Week 23 15.98 km (609.13 km so far)
Embarking on my last few miles now, leaving Drummand and travelling northwest, a few miles west of the Fyrish Monument (which represents the Gate of Negapatam, a port in Madras, India, which General Munro took for the British in 1781) and east of Loch Morie. I'm travelling through a region called Easter Ross, a loosely defined area in the east of Ross, Highland, Scotland.
Week 24 51.81 km (660.94 km so far)
Continuing through the Highlands, and crossing the Kyle of Sutherland near Altass. This is a big river that that separated Sutherland from Ross-shire, old Scottish counties that eventually became the Highland Region. Passing west of Loch Shin, and then across the Loch to finish at a place called Merkland Lodge (near Loch Merkland, in a very mountainous region with peaks on all sides). Sutherland is the last historic county I'll be travelling through, a rugged and sparsely populated region.
Week 25 49.2 km (710.14 km so far)
The final mark to Cape Wrath, passing through the mountainous regions of Sutherland. Very few people here, just wilderness and mountains. The remote far northwest point of Sutherland, Cape Wrath, is also the most northwesterly point in Scotland. The cape is separated from the rest of the mainland by the Kyle of Durness and consists of 280 square kilometres of moorland wilderness known as the Parph. The name Cape Wrath is derived from Old Norse hvarf ("turning point"), which I suppose is apt for the end of this imaginary journey.
Finish Line
After more than 700 km on foot, and over a hundred short walks since New Years Day 2021, I've now made it to June 2021. Lots of audiobooks and podcasts have been consumed, the evenings have gone from being dark and cold, to bright and warm. Plus I've learned a little about the north of the UK, with a little appreciation for the distances involved. I've been working from home the entire time, so these near-daily outings have given me some exercise and kept me sane during the strangest of years.
Now I guess I've reached a turning point, I best head home.
School of Physics and Astronomy, University of Leicester
Full Details: https://jobs.le.ac.uk/vacancies/2535/research-associate-in-planetary-atmospheric-science.html
Salary Grade 7 £34,804 to £40,322 per annum
Funding is available until 31 March 2022 with a possibility of extension
Closing date: 28 February 2021
The School of Physics and Astronomy at the University of Leicester invites applications for one or more Research Associates in Planetary Atmospheric Science.
The Research Associates will join the atmospheres team led by Dr. Leigh Fletcher, tasked with addressing the scientific aims of a European Research Council (ERC) grant to explore time-variable processes shaping the atmospheres of the giant planets. Successful candidates would have existing skills in planetary spectral data analysis and/or numerical modelling expertise of relevance to giant planet atmospheres. Research Associate positions will initially be for a period of 12 months, with funding available until the end of March 2022 with a potential for this to be extended.
The “GIANTCLIMES” programme seeks investigates natural cycles of meteorology, circulation, and chemical processes shaping the environments of the four giant planets over long spans of time. Inversions of planetary spectra, from ground- and space-based facilities, will be used to reconstruct these atmospheres in three dimensions to explore their temporal variability and the processes coupling different atmospheric regimes. The successful applicant will be expected to develop and expand on our pipeline for interpreting “Guaranteed-Time” and “Early-Release” giant planet observations from the James Webb Space Telescope. In addition, the applicant will conduct joint analyses of thermal-infrared, near-infrared, and microwave observations of giant planet tropospheres. We are therefore particularly interested in candidates with existing expertise in planetary data analysis, planetary atmospheres, and spectroscopic modelling techniques, but all applicants with a strong background in planetary science are encouraged to apply.
Applications much be made via the link above. Informal queries are welcome and can be made to Dr Leigh Fletcher on leigh.fletcher@le.ac.uk.
