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Mauna Kea Astronomy Tour

Mauna Kea is one of three main volcanoes that make up the island of Hawaii, the other two being Mauna Loa and (active) Kilauea. Mauna Kea remains a sacred mountain to Hawaiians and the very summit remains off limits as a holy place. Elsewhere, though, the top of Mauna Kea has been levelled off in various places to house the greatest concentration of large optical telescopes on Earth. This place is where the data for many of the great astronomical breakthroughs of recent decades has been gathered.

A dormant volcano may not sound like an ideal spot for the world’s largest assemblage of optical telescopes. But at around 4200m above sea level and surrounded by a huge mass of ocean water to stabilise temperatures, the seeing at Mauna Kea is amongst the very best anywhere. The icing (and weirdly, considering it’s in the tropics, Mauna Kea gets loads of snow and ice in winter) on the cake is that Hawaii has just a couple of towns and planning tightly controls light pollution everywhere, mandating narrow-band sodium lighting that can easily be filtered out. Meanwhile, though Hawaii is very wet in parts (the south hosts actual rainforests), the summit of Mauna Kea often lies above an inversion layer that traps the clouds below.

Unlike other parts of Polynesia, Hawaii is also of course one of the islands that makes up the 50th U.S. state, so Hawaii is easy and fairly cheap to get to and is highly developed in terms of facilities and infrastructure.

Many tourists, from America, Asia and Europe, visit tropical Hawaii for its beaches – some ideal for surfing, others great for diving and snorkelling. Many more come for honeymoons. But what if you’re interested in astronomy?  Can you visit Mauna Kea as a tourist day-trip? Yes, but with caveats …

Increasingly large numbers of tourists are deserting their new spouses, surf boards and snorkels to visit the observatories on Mauna Kea, usually to witness the spectacular sunset and to see the observatories opening up for the night. But unlike most other observatories in the U.S., that’s not just a matter of jumping in your rental car and taking a drive.

Doing it yourself

Currently, the summit of Mauna Kea is open to everyone. The problem is the road and the altitude. There is only one access road up Mauna Kea and the central section is a steep, graded dirt track at the height of a respectable Alp. They have reportedly kept the dirt section to discourage casual visitors, but it’s not working and the situation and rules may change soon.

The dirt portion of the road, though a bit rutted and bumpy, isn’t really too bad. In theory it is doable in an ordinary saloon car or a CUV, but normal engines and automatic transmissions do struggle. Unexpected kickdown followed by a spin happens regularly to those foolish enough to try it in the island’s favourite rental vehicle – the rear-wheel-drive ford Mustang.

But the real show-stopper for DIY visitors is that rental car insurance doesn’t cover this road. What’s more, some rental cars have GPS trackers to make sure. That means if you spin and crash, burn out the transmission or overheat the engine you will have a big bill – ten thousand dollars is apparently typical, including the extortionate cost of a tow truck (‘cos at that point you won’t be shopping around). Even if you make it up to the top in your rental car, there will then be the matter of getting back down in the pitch dark …

A wise alternative is to take an organised tour and though tours in general really aren’t my thing, I discovered a huge bonus I wasn’t expecting. But more on that later.

Which Tour?

There are many companies doing tours up Mauna Kea, but I chose one run by a dedicated outfit – Mauna Kea Summit Adventures. The tour wasn’t cheap (about $250 at the time of writing), but it was a fabulous experience. The rest of this article describes what it was like.

How the tour works

The tour collects you from a designated spot near the mountain and takes you the rest of the way in safety and comfort with an experienced driver and guide who has water, medicine and even oxygen on hand. My tour included a star party session after the sunset summit tour – more on that in a bit.

The tour began at 16:40, at the parking lot for the Mauna Kea Recreation Area just north off the main ‘saddle road’ that links the larger towns of Hilo and Kailua on the east and west coasts of the island. The tour itself uses several specially modified 4WD Mercedes buses, based on the familiar Sprinter van chassis, which the company has bought from Switzerland. The buses are a good enough reason to choose this particular tour – brand new with comfy leather seats and properly equipped for the conditions. The buses even have integral red lighting for the star party.

The summit is pretty cold by sunset, even in summer; the star party is even colder. The tour company provides a padded parka, but I wore thermals, a fleece and my own light down jacket as well. I was comfy; others got a bit chilly. Try to remember to bring some warm clothes – this is one place on Hawaii where a t-shirt and shorts just won’t cut it.

The tour ends at the same place, but very late in the evening. They offer a meal before you start and I’d advise you take it. There really isn’t time to eat much once you get into the tour bus and by the time you get back it may well be too late to get a meal in Hilo or Kailua.

The recreation area has plenty of parking, loos and picnic tables. If choose the meal option you get given a mess tin, some cutlery, a napkin and forty minutes to eat at one of the picnic spots. The mess tin doesn’t look too inviting, but contains a delicious, piping hot home-cooked lasagne.

I mention the toilets because there aren’t any others apart from a single portaloo at the summit which gets very long queues. There is of course plenty of barren cinder in the darkness around the star party later.

Getting there

Hawaii isn’t a large island, but the roads can be slow and congested. It took about an hour to reach the designated parking lot from Kailua. It would be about the same from Hilo. The road, the 190, goes up from Kailua’s main shoreside street, up past a group of supermarkets including Wal Mart and Safeway, then rapidly climbs. Views across the north shoreline are spectacular and there is a scenic pullout for pics.

Once free of the populated areas, the route turns right onto Saddle Road (the 200), gets a 60 mph limit and climbs fast through wild and barren lava and grasslands between Mauna Kea and Mauna Loa.

By the way, don’t end up at the wrong observatory! Mauna Loa on the south of the road has one too – complete with domes – but it’s much smaller and devoted to meteorology not astronomy. The Mauna Loa observatory is accessed by a fully-paved road from an unmarked right turn a few miles towards Hilo from the recreation area. If you feel like climbing the highest mountain on Earth (in terms of base-to-summit), a small parking area at the Mauna Loa observatory is the starting point. The gruelling climb over steep and remote lava to the summit cairn by the giant crater takes all day, but the other worldly view of Mauna Loa’s gigantic crater is worth it.

4WD tour bus in the Recreation Area parking lot

Dinner at the Mauna Kea Recreation Area before the tour

Mauna Loa and the (now closed) visitor centre from the Mauna Kea access road

Getting to the summit

I was met at the Mauna Kea Recreation Area parking lot by a friendly guide and driver named Arthur who had a degree in geology and a minor in astronomy, so he really knew his stuff.

Once we had eaten, the tour set off at about half past five, turning onto the main road towards Hilo for a few miles and then off left towards Mauna Kea.

As we drove upwards, slowly and carefully, Arthur gave a lively and informed talk about the observatory and the mountain. There is a visitor centre at the end of the paved road, but it’s closed at the moment. Arthur said the reason for the closure is road upgrades to handle the components for the next Big Science tool to be built at Mauna Kea – the 30m telescope. Stalled for some years due to planning disputes, preparations for the 30m have started in earnest this year (2019).

The drive up takes an hour or so and its mostly comfortable, apart from some shaking and bumping on the dirt section, where Arthur also paused his talk to concentrate on the road. We only stopped briefly at the visitor centre to hand in some forms.

Although they do carry oxygen, they have rarely needed it. I am reasonably fit and found no problem with walking and jogging around at the summit from one photo spot to another. The message is: don’t worry about the altitude unless you have significant health issues.

Views on the way up were spectacular, across barren lava fields towards Mauna Loa and the ocean beyond. Once the road becomes black-top again (yes, oddly, the top section is paved), we passed an area used for testing various space hardware (rovers and Apollo space suits) and a radio telescope dish, part of the Very Long Baseline Array, next to which we would be parking for the star party later.

The Mauna Kea Observatories

Unlike other U.S. observatories, Mauna Kea isn’t run by a single institution and none of the tours include entry to the observatories and domes. I believe the Subaru observatory does offer tours, but during the day at a time that doesn’t match up with the tour companies, so it isn’t a practical visit unless you can arrange alternative transport. The W.M. Keck observatory has a surprisingly large HQ down in the town of Waimea, north of the mountain, which you can visit separately.

My tour allocated lots of time in the summit area for photos before and just after sunset. I noticed that other tour buses generally arrived later and left earlier, so the one I did is a good one for astronomy enthusiasts who want to see all the domes open before departing the summit.

The summit isn’t one area, but several different ones, levelled into the bare reddish cinder of the volcano and connected by winding blacktop. These different areas hold different groups of observatories. There’s a lot to see, so it’s worth learning a bit about the different facilities before you go.

We first parked up by the NASA Infrared Telescope Facility that houses a 3m telescope in a smallish silver dome atop a building the shape of a giant Mac Mini. It’s a good place to start because just across the road are the giant interlinked spherical domes of the two Keck 10m optical telescopes that have so revolutionised astronomy since the early Nineties.

Beyond the Keck Observatory, which incorporates extensive labs and maintenance facilities, is the odd-looking (it’s not a dome; more like a giant electrical plug) Subaru Observatory, housing Japan’s 8.2m telescope (and possibly the largest instrument ever fitted with an eyepiece, for the enjoyment of the princess who opened it).

Below the NASA ITF and a bit farther off were another cluster of domes, including the James Clerk Maxwell Telescope, a 15m sub-millimetre dish housed in a cylindrical observatory. The JCMT sits between two other sub-millimetre instruments housed in their own observatories and one smaller radio dish in the open.

After that, we drove higher for the main stop of the evening, right next to the UK Infrared Telescope, a 3.8m optical instrument housed in a very characteristic dome with ‘windows’ around the side. It has a photogenic, rather steampunk look you often see in images of Mauna Kea.

On the other side of the UKIT were three other large domes. The University of Hawaii 2.2m telescope has a white dome with a ‘nose’ extension. Gemini North (my favourite) is an 8.1m optical/IR telescope housed in a giant silver dome with a broad equatorial band running around it whose purpose would soon be revealed. Furthest off was the CHFT (Canada France Hawaii Telescope), a 3.6m optical instrument in a giant puffball on a round base.

Sunset Views

As we arrived, the Sun was dropping towards the horizon, the air growing finger-numbingly chill. Buses and cars were arriving and people setting up their cameras ready.

The UKIRT was just opening its dome shutters. Further up the hill, Gemini North was still closed, but its giant fans were roaring away to evacuate the warm air of the day from the dome. Further on, a group of visiting astronomers were gathering on the balcony of the CFHT to watch the sunset too!

The spectacle of a reddening sun dropping into clouds over the ocean beyond the Keck observatory was certainly worth the trek up the mountain. Here and there, the clouds broke to reveal the blue of the Pacific. The thin clouds overhead were turning deep reds and golds.

Even more interesting to me, though (sorry!), was Gemini North. I had clambered right up next to it and as I watched, the belt around the equator of the dome opened to reveal its unique system of vents that run right around dome to help equilibrate the observatory. Soon, the Gemini’s dome shutters opened too and it began to spin around, revealing the giant telescope within, ready for a night’s work. A really exciting moment for me – Big Science in action!

We stayed for ages until we were all pretty cold, taking loads of photos of the sunset and the reddening dusk reflecting in the domes. Then it was time to leave the astronomers to their darkness. By then, it was nearly dark and all the domes, including the Keck pair, had opened their shutters and started spinning around to acquire their first targets and start streaming data back to universities around the world.

W.M. Keck Observatory with Subaru behind

NASA Infra-red Telescope

James Clerk Maxwell Telescope with other sub-millimetre observatories around it

UK Infra-Red Telescope

Gemini North and the Canada France Hawaii Telescope. Note the group gathered on the CFHT balcony to watch the sunset!

After sunset: ready for the night’s observing

Star Party

To be honest, when I booked the tour, I hadn’t thought much about the offer of an observing session afterwards – I was there to see the world’s greatest cluster of observatories! As it turned out, the star party was a fantastic opportunity. Why? I had expected it to be down the mountain somewhere, maybe at the visitor centre. In the event, the buses pulled into a dirt side road just below the summit and stopped close by the VLBA dish. We were to be viewing under the same world-class 4000m skies as Keck and Subaru and Gemini!

The next surprise was the scopes themselves. I was expecting budget scopes, may ST80s or something. But the back of the buses opened to reveal fully equipped Celestron C11s, excellent ones as it turned out.

As the last of the dusk light bled from the sky, the VLBA dish was whirring around behind us in the dark, giving the place a sci-fi atmosphere. Arthur was quickly getting the C11 ready and the buses had switched to a full set of red lights. But my excitement really mounted when I looked across towards the dark bulk of Mauna Loa in the south. I could see the lights of the NOAA observatory there, but above the mountain hung the Southern Cross!

I just hadn’t realised that Hawaii, at nineteen degrees north, actually has good views of much of the southern sky too – one of the reasons it’s such a perfect location. The Southern Cross has long been on my list, but I had assumed I would need a trip back to Australia or NZ to see it. To the right of the cross was something even more interesting from my observing bucket list – the Eta Carinae nebula!

The Eta Carinae nebula is one of the largest and brightest in the sky, even brighter than the Great Nebula in Orion. Easily visible to my eyes, it was the evening’s first target for the C11s. Suffice to say that with a low power eyepiece it was a stunning view, filling the field and easily yielding its ‘flower’ shape with dark lanes dividing the ‘petals’, with plenty of structure in the nebulosity visible too. The high, dark skies of Mauna Kea really delivered and then some. And to think I had been planning a trip down under to normal sea-level skies and carrying some tiny refractor to view it some day!

The Southern Cross and Eta Carinae would have been a fantastic prize on their own, but there was more. As everyone enjoyed their view of Eta Carinae, I walked off into the thick darkness near the VLBA dish to do some landscape astrophotography; some others had their tripods and DSLRs out doing the same. Meanwhile, Arthur set the C11 onto Omega Centauri.

Omega Centauri is another fantastic southern sky object which I had never seen. Situated just above and to the east of the Southern Cross, it is the largest and brightest globular cluster in the Milky Way and made a simply stunning sight through the C11 – filling the field of view with a gigantic mass of tight-packed stars and resolved right to the core. This was a globular but not as we (in the north) know it - much more impressive than M53 a few days later … albeit seen through the 36” at Lick in California!

The star party continued through several other interesting targets, including the Sombrero Galaxy, which again gave a superb view with its bright halo and dark-rimmed dust lane ‘brim’.

The final object of the night’s viewing was just appearing over the rim of the cinder cone beyond the VLBA disk, a dazzlingly bright Jupiter. If anything proved the quality of Mauna Kea’s steady and transparent seeing this was it. That view of Jupiter showed a mass of detail: tiny dark and bright storms set among zillions of faint belts in seeing bizarrely still and completely steady. Apart from the 60” at Mount Wilson, easily the best view of Jupiter I have ever had. It also proved to me that seeing is the most important factor for planetary detail.

Southern Cross, Eta Carinae and Omega Centauri with the solitary light of the NOAA observatory across on Mauna Loa below

The Very Long Baseline Array at Mauna Kea

Back to Earth

The observing session went on until late and included gourmet hot chocolate (tea and coffee were also available) to warm our numbed fingers and served with home-made biscotti before Arthur quickly and efficiently packed up the C11.

We finally rolled back into the Mauna Kea Recreation Area parking lot at 22:30 and I started the long red-eye drive back to my resort on the coast south of Kailua. It had been a simply fantastic experience and one of my most memorable astro evenings ever, with the stunning views of southern DSOs besting the sunset views of the observatories for me.


Highly recommended. If you are in Hawaii you simply must do this, but try to choose a moonless night when the Southern Cross is up for the best views.