{"id":180,"date":"2023-06-18T10:51:00","date_gmt":"2023-06-18T10:51:00","guid":{"rendered":"https:\/\/www.hikingonpluto.com\/?p=180"},"modified":"2023-09-07T05:40:46","modified_gmt":"2023-09-07T05:40:46","slug":"the-seven-summits-of-the-solar-system","status":"publish","type":"post","link":"https:\/\/www.hikingonpluto.com\/index.php\/2023\/06\/18\/the-seven-summits-of-the-solar-system\/","title":{"rendered":"The Seven Summits of the Solar System"},"content":{"rendered":"\n

Conquering the seven highest peaks of seven continents on Earth is classic challenge to some, trodden path banality to others. It\u2019s been done by at least 100, some estimate by 500 people, including by a 76-year old mountaineer, a married couple and a mother-daughter climbing pair. The current fastest record-holder bagged all seven peaks in less than 4 months. It seems there is little new to bring to the table on Earth – though you could still pull headlines if you climbed as a team of triplets.<\/p>\n\n\n

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Once we start hiking in the Solar System, however, there will be plenty of opportunity to be the first. One starter challenge \u2013 apart from little details like space rockets, radiation shielding, and equipment that can keep you alive from -180 to +380 Celsius while still allowing you to actually walk anywhere \u2013 will be to define the list of seven summits on Solar System scale. There has been enough debate on Earth already on what qualifies as \u201cEurope\u201d or \u201cAustralia\u201d \u2013 but we can reasonably expect a much fiercer debate when it comes to our wider neighborhood.<\/p>\n\n\n\n

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Which summits to choose in the Solar System? (image from freepik)<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Where would be the seven summits of the Solar System? As a start, we have 8 planets \u2013 but only four of them (Mercury, Venus, Earth, Mars) are composed of rock, the four outer planets (Jupiter, Saturn, Uranus, Neptune) are gas giants, unfit for any climbing. They have plenty of moons, however, with mountains on them. There are also some asteroids with remarkable peaks in the asteroid belt between the orbits of Mars and Jupiter. We have five dwarf planets in our system, of which at least Pluto certainly has some enticing heights. So, how to choose from this bonanza?<\/p>\n\n\n\n

What follows here is only one possible listing of the Solar System\u2019s seven summits, with some thought devoted to possible variations. No rush, we can all work on our dream lists at leisure \u2013 at least for the next decade, it\u2019s not likely yet that any human would set foot on these peaks.<\/p>\n\n\n\n

1. Mercury<\/p>\n\n\n\n

Mercury, though closest to the sun, is not the hottest planet \u2013 that award goes to Venus, thanks to the runaway greenhouse effect on the latter. Still, Mercury is a planet of extreme temperature fluctuations, from scorching 430 C during day to minus 180 C at night \u2013 a swing of 600 Celsius degrees, a record for the Solar System. This level of daytime heat is enough to keep even rocks in a semi-molten, gooey state, making \u201csolid ground\u201d a rather relative term.<\/p>\n\n\n\n

You may prefer visiting the poles, which never experience sunshine, and even hold onto some frozen ice \u2013 except that there are no peaks to climb in that area. Another proposed solution is to follow the terminator line, the slowly shifting zone where the Sun is continuously just rising, as a way to avoid scorching and chilling. This region would experience a relatively constant temperature around -100 C, perfectly comfortable for climbing (by Solar System standards). You would of course need some good logistics to keep to a trajectory which allows you to actually climb the highest peak while it is in the safe zone.<\/p>\n\n\n\n

Aptly named Caloris Montes (“Heat Mountains”) are the highest mountain range on Mercury. We don\u2019t have exact data for the peaks, but it\u2019s unlikely that any of them would be higher than 3000 meters, making it an easy climb – disregarding the extreme temperatures, solar winds and magnetic tornadoes, of course.<\/p>\n\n\n\n

2.      Venus<\/p>\n\n\n\n

Venus\u2019s highest peak, Skadi Mons reaches 11 kilometers (6.8 miles) so it beats Mount Everest, and it has some very exotic and lethal features. So exotic and lethal, in fact, that it is a top contender for the \u201cdeadliest peak of the Solar System\u201d title [https:\/\/www.hikingonpluto.com\/index.php\/2023\/05\/24\/the-7-best-active-holiday-destinations-in-the-solar-system\/<\/a>]. It may be the ultimate extreme sport destination of our system, except that the equipment needed to stay alive would exclude any kind of exercise. Adding Venus to our list of Seven Summits could delay the completion of the challenge by a 100 years \u2013 so we\u2019ll examine some possible alternatives.<\/p>\n\n\n\n

3.      Earth<\/p>\n\n\n\n

This is the list where climbing Mount Everest counts as the walk in the park. All you need is a plane ticket, good altitude hiking gear, and a few bottles of oxygen. One specific problem you\u2019d face, however, is unlikely to come up elsewhere: overcrowding. One excellent account of Himalaya climbing, which shows that it is not such an easy challenge after all, is Jon Krakauer\u2019s Into Thin Air [http:\/\/[https:\/\/jonkrakauer.com\/<\/a>].<\/p>\n\n\n\n

4.      Mars<\/p>\n\n\n\n

After Everest, Mars\u2019s Olympus Mons will be probably the easiest and at the same time, most rewarding climb. To start with, with 2.5 times the altitude of Everest, it\u2019s the highest peak of the Solar System \u2013 or not [https:\/\/www.hikingonpluto.com\/index.php\/2023\/05\/24\/the-7-best-active-holiday-destinations-in-the-solar-system\/<\/a>]. But even if it\u2019s relegated to second highest, a peak of almost 22 kilometers high is nothing to find fault with. Olympus Mons also holds the title of the highest volcano of the Solar System, and its base is as large as France or Arizona. By Solar System standards, Mars is next door, and you could accomplish the one-way trip in 7 months \u2013 only Venus is closer (average 4 months), but all other destinations would require considerably longer trips. Flying time to Jupiter, for instance, could take more than 5 years.<\/p>\n\n\n\n

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Olympus Mons, Mars<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Moreover, Mars has just the ideal gravity for mountaineering: you\u2019d weigh roughly one third of your Earth weight, so you\u2019d feel extra fit, but it\u2019s still strong enough to keep you from bouncing off the ground. Though Olympus Mons itself is rather chilly – count with temperatures around 60 C below zero \u2013 you can follow your climb with some rest and relax in balmy above zero Celsius atmosphere in other parts of Mars. Talking of atmosphere, Mars has it, as it can also boast with water ice, non-negligible air pressure and a lot more sunshine than the outer planets. All this makes Mars the most habitable planet in the Solar System after Earth \u2013 and the friendliest to hiking, evidently.<\/p>\n\n\n\n

 5.  Phaeton<\/p>\n\n\n\n

With Mars, the list of evident summits ended, and we enter a more speculative realm. The next planet after Mars is failed-star gas giant Jupiter with its hundred moons. But Jupiter is very far away, and on the way there, we need to cross a massive asteroid belt, which has some attractive destinations on its own. This asteroid belt, according to some views, is the remains of a hypothetical 5th<\/sup> planet, Phaeton, which had rotated so fast that it finally shattered to debris. While mainstream views hold that there was never any 5th<\/sup> planet, it could still be justified adding an object from the asteroid belt to our seven summits list.<\/p>\n\n\n\n

Unfortunately, dwarf planet Ceres doesn\u2019t have any notable peaks. Rheasilvia crater on the asteroid Vesta, however, has a peak emerging in the center of the impact basin that rises to approx. 22 kilometer (in other sources, 20-25 kilometres), thus could be taller than Olympus Mons. <\/p>\n\n\n\n

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Rheasilvia basin<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

As the whole of the asteroid\u2019s surface is about the size of a larger Earth country (say Pakistan or Nigeria), this crater and its peak are among the most defining features of it. Typical daytime temperature on Vesta is around -60 C, similar to what you can expect on Olympus Mons, but gravity is just a fraction of Mars\u2019s, meaning that you could easily jump 20 metres high [check out this highly entertaining link https:\/\/cosmos-book.github.io\/high-jump\/index.html<\/a>]. Another plus for Vesta is that there could be buried ice under the surface – always useful to check before packing for your trip.<\/p>\n\n\n\n

6.      Jupiter<\/p>\n\n\n\n

Jupiter is the undoubted king of the Solar System, a massive bully who weighs twice as much as all the other kids on the playground (i.e. planets) put together. Still, it would take some significant beefing up to turn Jupiter into a star: it would need 1000 times its mass to become a star like our Sun, and about 13 times its mass to make it to a brown dwarf star. This latter is probably the kind of star Jupiter is engineered into in Clarke\u2019s 2010: Odyssey Two \u2013 a possibility that would not only sustain life on nearby moon Europa, but would also make hiking on Jupiter\u2019s moons a considerably nicer experience.<\/p>\n\n\n\n

As it is fitting a bully, Jupiter has many sidekicks. About a hundred moons orbit the planet, some of them so large that they could qualify as planets. Ganymede, for instance, is the biggest moon in our Solar System, bigger than the planet Mercury, and way bigger than poor demoted Pluto. As Ganymede is planet-sized, it has some planet-like characteristics \u2013 an underground saltwater ocean, a magnetic field and a thin oxygen atmosphere. Thanks to its unique magnetic field, Ganymede also has a phenomenon similar to Earth\u2019s aurora borealis – ribbons of glowing, hot, electrified gas, visible close to the poles. As the moon\u2019s mass is not far from Mars, gravity is of similar proportions \u2013 optimal for hiking in heavy gear.<\/p>\n\n\n\n

It all sounds like ideal terrain for future terraforming, but are there mountains to climb? We don\u2019t know for sure yet. A large part of the surface is covered by cracked, icy ridges that certainly have some peaks, though it\u2019s not likely that they would be very high \u2013 perhaps not 1000 meters, even. For higher peaks, the best bet in the vicinity is on moon Io \u2013 the place where hell literally freezes over [https:\/\/www.hikingonpluto.com\/index.php\/2023\/05\/24\/the-7-best-active-holiday-destinations-in-the-solar-system\/<\/a>]. There are many peaks, the highest reaching 18 kilometers. Your hiking pleasure, though, might be seriously reduced due to the super-robust shielding you need to add to your gear to survive the triple lethal radiation dosages on the Solar System\u2019s most bizarre moon. Perhaps better to stick to Ganymede.<\/p>\n\n\n\n

7. Saturn<\/p>\n\n\n\n

Saturn is another gas giant, and on top of its unique ring of debris, it has even more moons than Jupiter \u2013 124 and counting. The biggest moon is Titan, as it befits the name, second-largest moon of the Solar System. If rafting on a river of methane at torchlight is your thing, you will love Titan [https:\/\/www.hikingonpluto.com\/index.php\/2023\/05\/24\/the-7-best-active-holiday-destinations-in-the-solar-system\/<\/a>]. But for hiking experience, you\u2019d better of heading to another moon, Mimas, which in spite of its small size (1\/8 of our Moon), is home to the highest peak of the Saturn system. It is also the only place around where you can hoist yourself up to a mountaintop and be still four kilometers underground \u2013 as Mimas\u2019s 6000 meters peak is located inside a the 10,000 meters deep Herschel Crater.<\/p>\n\n\n\n

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It is not the Death Star – asteroid Mimas<\/figcaption><\/figure>\n\n\n\n
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Saturn rising (artistic image)<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Due to Mimas\u2019s smallness, the climb would be a breeze. Gravity is so low that you could jump almost 80 metres high, and it would take you a good 50 seconds to fall safely back on the ground. Not much good for watchtower-building business, Mimas. Even though the moon has an uncanny resemblance to the Death Star, it is a friendly world for this part of the Solar System: most of its terrain, roughly the size of Spain, is composed of water ice, and it doesn\u2019t have any volcanoes or dangerous tectonic activity. Ironically, the only slightly disappointing thing would be the view \u2013 you could enjoy a much more spectacular sights during your journey from the spaceship approaching Saturn than from Mimas. As the moon orbits the planet at close distance and near to the equator, the rings would probably look razor thin. Golden-hued Saturn itself would still be beautiful, however, and would loom very large on the horizon \u2013 about twenty time bigger than the Moon on our sky.<\/p>\n\n\n\n

8.      The outer Solar System<\/p>\n\n\n\n

We have reached number seven with Saturn, so if you have ticked off all destinations so far, no need to read on (and congratulations!). However, there may be adventurers who prefer omitting Earth from the list (too easy), or would rather not visit Mercury and Venus (too hot), and may be interested in cooler, if further away, alternatives.<\/p>\n\n\n\n

While the outer Solar System is well-supplied with attractive hiking destinations, from 20-kilometer cliffs to cryovolcanoes, travel time is becoming a serious issue. I\u2019ve recently watched a Star Trek (Deep Space 9) episode, which kind of illustrated the limits of present-day technology. \u201cHe is in this solar system, so we must be able to catch up with him!\u201d says one of the Starfleet characters while chasing after a villain at the border of the Federation. And in just a few minutes, they reach the moon where the antagonist is hiding.<\/p>\n\n\n\n

It would be marvellous to whizz through our Solar System at such speeds. But even light takes 2.5 hours from Earth to Uranus. Given that the fastest non-manned spacecraft we\u2019ve ever built is more than 13,000 times slower than the speed of light, whizzing is quite out of the question.<\/p>\n\n\n\n

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Travel distance becomes an issue in the outer Solar System<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Estimating a realistic travel time to the planets is not a straightforward task, as 1) to state the obvious, they are moving, and their orbital position can make a big difference 2) a lot depends on your cargo \u2013 how much fuel, water, oxygen etc. you need to carry, 3) you need to decide if you only plan a flyby, or you need to decelerate and land. The only actual experience we have is from space probes Voyager 1-2 and New Horizon.<\/p>\n\n\n\n

At our current pace, the Solar System seems very, very big. Our fastest-ever space probe, New Horizon, zipped by Jupiter in a record 405 days after its launch from Earth. This was a gravity-assisted flyby, however, without carrying humans, human life-support, and without slowing down to orbit and land. Even with this light step, it took New Horizon more than 5 years to cross Uranus\u2019s orbit \u2013 without actually catching up with the planet, which was further away on its route \u2013 and eight years and eight months to cross Neptun\u2019s. It reached its next milestone, Pluto, in 9.5 years.<\/p>\n\n\n\n

Once astronauts (or hopeful hikers) are on board, all these travel times would take considerably longer, so we need to find faster propulsion alternatives to have a realistic go at the outer Solar System. Still, the day will come when we can extend our seven summits quest to destinations further down space-time. So what are the best options beyond Saturn?<\/p>\n\n\n\n

8. Uranus<\/p>\n\n\n\n

Earth is often called the \u201cblue planet\u201d, but Uranus and Neptune are also very blue \u2013 not due to any seas, but because they have methane in their atmospheres, which absorbs the color red from the sun’s light. <\/p>\n\n\n\n

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Uranus and Neptune – shades of blue<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Also, both are \u201cice giants\u201d as opposed to the \u201cgas giants\u201d Jupiter and Saturn. While gas giants are, well, mostly gaseous, with very little rock and ice, ice giants are largely composed of compressed, slushy water and ammonia, and relatively big rocky, icy cores. Still, this means no solid surface, so you couldn\u2019t land, maximum hover over the planet. So again, we need to look for the moons for climbing options.<\/p>\n\n\n\n

Uranus is poorer in moons than its gas giant brothers, but its moon Miranda is home to one of the most massive cliffs of the entire Solar System [https:\/\/www.hikingonpluto.com\/index.php\/2023\/05\/24\/the-7-best-active-holiday-destinations-in-the-solar-system\/<\/a>]. The cliff, made of frozen ice, is located near the moon\u2019s south pole. For height, estimates vary from 7 to 20 kilometers, and steepness is also in question \u2013 this is still a lesser-explored corner of the Solar System. But it is entirely possible that there\u2019s a 20-kilometre high, very steep cliff on Miranda \u2013 just imagine a cliff wall twice the height of Mount Everest! Gravity is comparable to Saturn\u2019s moon Mimas, so it would take you a loooong time to fall off that cliff – depending on the high estimate used, it could take full 8-12 minutes to hit the bottom. A dream destination for big wall climbing, bungee jumping and all kinds of extreme sports \u2013 though forget paragliding, as sadly there is no atmosphere. <\/p>\n\n\n\n

9. Neptune<\/p>\n\n\n\n

Neptune is so far away from the Sun that high noon on the planet and its moons would seem like dim twilight to us \u2013 like winter in North Alaska, all year round. Neptune, as befits the god of seas, is also a blue ice giant, with no solid surface to land on. Climbing action would probably focus on Neptune\u2019s biggest moon, Triton. Triton in many ways is similar to Pluto \u2013 similar size, similar surface materials, such as nitrogen, methane and carbon monoxide, similar mass and density.  Also like Pluto, Triton was likely part of the Kuiper asteroid belt long ago \u2013 just later it got captured by Neptune\u2019s gravity field.<\/p>\n\n\n\n

Unfortunately for hikers, and unlike Pluto which has some decent peaks, Triton\u2019s surface elevation varies very little \u2013 it is mostly smooth and covered with ice, and has often been likened to a cantaloupe. Topography hardly varies by more than one kilometer. Triton also holds the award for being the coldest known object of the Solar System, with an average temperature of minus 391 degrees Fahrenheit (minus 235 Celsius.) The only interesting features are cryolava lakes and active geysers, spewing up ice that is then blown around by atmospheric winds \u2013 a world like the planet Hoth, in sum, but despite some organic chemicals, probably without the wildlife. <\/p>\n\n\n\n

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Hoth, but without wildlife<\/figcaption><\/figure>\n\n\n\n
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Azure blue Neptune<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

As compensation, the view of Neptune would be breathtakingly beautiful from the moon\u2019s surface \u2013 ten times bigger than our own moon, and a fantastic azure-blue colour.<\/p>\n\n\n\n

10.   Pluto<\/p>\n\n\n\n

Dwarf planet Pluto may be a tad smaller than Triton, ending in its famous demotion from planet to dwarf planet, but unlike Neptune\u2019s moon, it does have mountains. The highest peak on Pluto, at around 6200 meters, is comparable to the top of the Himalaya if we consider its height base-to-top, and the biggest mountain ranges are even named after the first climbers to reach Mount Everest – Tenzing Norgay and Edmund Hillary.<\/p>\n\n\n\n

Pluto\u2019s mass is only 1\/6 of Earth\u2019s moon, so gravity is very low \u2013 you could easily jump 7-8 metres up above, and then enjoy the views for a good 9-10 seconds while falling back. Though Pluto is a shade warmer than Triton, there is not much to warm the surface, so temperatures remain below minus 220 Celsius all Pluto-year round, with little difference between day and night.<\/p>\n\n\n\n

Hiking on Pluto would be a rewarding experience [https:\/\/www.hikingonpluto.com\/index.php\/2023\/04\/02\/hiking-on-pluto\/<\/a>], not any harder than most hikes in the outer Solar System. Our Sun would be only a tiny, diamond-bright pin on the sky, while Pluto\u2019s moon, Charon, would loom huge \u2013 they are so close in size that they are considered as our neighbourhood\u2019s only double (dwarf) planetary system. Charon is a worthwhile hiking destination itself, with a canyon so deep as if the very crust of the moon had cracked open. <\/p>\n\n\n\n

Pluto has plenty of water ice, a thin haze of atmosphere, and it is strategically well-located in the entryway of the Kuiper Belt, a disc-shaped vast area of hundreds of thousands of icy objects. <\/p>\n\n\n\n

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Kuiper Belt objects<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Together with the even more outer disc of the Oort Cloud, they stretch across vast space almost halfway to the next solar system, Alpha Centauri. The Kuiper Belt is host to most of the dwarf planets of our Solar System, a surprisingly colourful bunch of asteroids and larger bodies. Some theories imagine even more exotic objects lurking in the Kuiper Belt \u2013 like Planet Nine or a Ping-Pong ball-sized black hole. With its strategic location and hospitable characteristics, Pluto would likely become a base for exploration for the outer realms, hosting astronauts, scientists and adventurers \u2013 and offering a good hiking break to anyone interested.<\/p>\n\n\n\n

We\u2019ve worked our way through the whole Solar System from Mercury to Pluto to explore hiking destination. To take stock, here\u2019s a subjective but well-researched list of the prizewinner seven summits of the Solar System:<\/p>\n\n\n\n

    \n
  1. Caloris<\/strong> Montes<\/strong><\/mark>, 3000 metres (Mercury)<\/li>\n\n\n\n
  2. Mount Everest<\/mark><\/strong>, 8849 metres (Earth)<\/li>\n\n\n\n
  3. Olympus Mons<\/mark><\/strong>, 22,000 metres (Mars)<\/li>\n\n\n\n
  4. Rheasilvia<\/mark><\/strong>, 22,000 metres (Vesta \u2013 asteroid belt)<\/li>\n\n\n\n
  5. Herschel peak<\/mark><\/strong>, 6000 (or -4000) metres (Mimas – Saturn)<\/li>\n\n\n\n
  6. Verona Rupes<\/mark><\/strong>, 20,000 metres (Miranda – Uranus)<\/li>\n\n\n\n
  7. Tenzing Montes<\/mark><\/strong>, 6200 metres (Pluto)<\/li>\n<\/ol>\n\n\n
    \"\"<\/figure>","protected":false},"excerpt":{"rendered":"

    Conquering the seven highest peaks of seven continents on Earth is classic challenge to some, trodden path banality to others. It\u2019s been done by at least 100, some estimate by 500 people, including by a 76-year old mountaineer, a married couple and a mother-daughter climbing pair. The current fastest record-holder bagged all seven peaks in […]<\/p>\n","protected":false},"author":1,"featured_media":267,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[8,10,20,19,7,13],"class_list":["post-180","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hikinginthesolarsystem","tag-hiking","tag-mars","tag-mercury","tag-seven-summits","tag-solar-system","tag-venus"],"_links":{"self":[{"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/posts\/180","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/comments?post=180"}],"version-history":[{"count":20,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/posts\/180\/revisions"}],"predecessor-version":[{"id":268,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/posts\/180\/revisions\/268"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/media\/267"}],"wp:attachment":[{"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/media?parent=180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/categories?post=180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hikingonpluto.com\/index.php\/wp-json\/wp\/v2\/tags?post=180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}