Author: Will Gater

Bringing The Story of the Solar System to the stage

If you’ve been following my Twitter feed in recent months you’ll probably have already seen me mention that I’ll be performing my first live theatre show on 19th November, called The Story of the Solar System. I’ve had huge fun over the past year developing the show, the set design and props and am thrilled that it’ll get its first outing at the amazing Tacchi-Morris Arts Centre here in Somerset.

The show tells the incredible tale of our planetary neighbourhood through a mix of storytelling, live demos, spectacular space imagery and audience participation. During the show we’ll explore the many and varied worlds of the Solar System and look at a bit of the science behind our little corner of the Cosmos. We’ll descend to the surface of Saturn’s largest moon, whirl around a comet with the European Space Agency’s Rosetta spacecraft and, along the way, find out about some of the men and women who pioneered the study of the planets and other objects that orbit the Sun.

Huygens press shot_25cm300DPI copyOne of the ‘stars’ of the show, a 1:3-scale replica of the Huygens probe. Credit:

You can buy tickets for the show through the Tacchi-Morris Arts Centre box office online or over the phone on 01823 414141.

And if you have friends, family or work colleagues who may be interested in a theatre show with a astronomical twist please spread the word with the buttons below.

Total lunar eclipse photos – 28 September 2015

IMG_3689_DxO_eclipse_start of totality_28092015The beginning of totality during the total lunar eclipse – 28 September 2015. Credit: Will Gater

On Monday morning the skies were clear over Somerset and we were treated to a beautiful total lunar eclipse. Totality was notably dark producing a much more dramatic drop in sky brightness than the one I remember from the 2007 total lunar eclipse. The purple/turquoise fringe of the umbral shadow (caused by stratospheric ozone absorption) seemed less pronounced however. Below are a few of my pics from the event. You’ll also find them over on my new astro image site

Harvest_Supermoon_pre__eclipse moon rise_27092015The full Moon rising on the night of the 27 September 2015. Credit: Will GaterIMG_3642_DxO_perigee full Moon_27_28092015The perigee full Moon before the eclipse had begun. Credit: Will Gater

IMG_3653_DxO_lunar eclipse_partial_phase_28092015
The umbral shadow of the Earth progressing across the disc of the Moon. Credit: Will Gater

Lunar eclipse full montage September 2015Composite montage of the entire lunar eclipse from beginning (right) to end (left). Credit: Will Gater

IMG_3731_DxO_lunareclipse_28092015_ozone_edgeThe delicate purple edge of the umbral shadow shortly after totality had ended. Credit: Will Gater

IMG_9054_DxO_eclipse widefield stars of pisces_28092015Stars down to around 13th magnitude showing up behind the totally eclipsed Moon. Credit: Will Gater

IMG_3713_DxO_eclipse wide field_28092015A wide-field view of the totally eclipsed Moon. Credit: Will Gater

Umbral shadow montage eclipse 28092015Montage showing the rough outline of the umbral shadow. Credit: Will Gater

IMG_3706_DxO_eclipse_28092015_0248utThe moment of greatest eclipse. Credit: Will Gater

IMG_3693_DxO_eclipse_28092015The totally eclipsed Moon above thin cloud and a hedgerow. Credit: Will Gater

Eclipse chasing in the Faroe Islands – 20 March 2015

Totality first processTotality, and the Sun’s glowing corona, from near the town of Runavik in the Faroe Islands. Credit: Will Gater

Last week I was the guest astronomer on an Omega Holidays trip to the Faroe Islands for the total solar eclipse of 20th March. I’ll try to post a full report soon, but in the meantime here are a few pictures from what was an incredible, and at times nerve-wracking, day chasing the shadow of the Moon.

IMG_1242 copyOur flight left Stansted airport at just after 3:15am on the Friday morning. Note the astronomical airline name!

IMG_1249 copyWe arrived in the Faroe Islands at 5:30am & were greeted with thick cloud, mist & drizzle.

IMG_0410edited_webAs our convoy of coaches drove to our observing site, a spectacular peninsula near the town of Runavik looking out over the Atlantic, we could see small breaks in the clouds.

IMG_0414_edited_webThe wind & rain continued in the run up to the start of the eclipse. We watched as a cruise ship offshore valiantly chased the gaps.

IMG_0406_edited_webA panorama looking south from our observing site. The capital, Tórshavn, is on the right. Click to enlarge!

IMG_1282 copyMy eclipse photography kit. The exposed location made for an incredible view but meant photography was a challenge to say the least! My rucksack is attached to the tripod with a karabiner in an effort to reduce wind vibration.

_MG_0419_DxOMy first photo of the partial phase of the eclipse, taken with a white-light solar filter barely a few minutes after first contact. Credit: Will Gater

_MG_0450_DxODuring the first partial phase of the eclipse the Sun made only a few brief appearances. Credit: Will Gater

_MG_0474_DxO_editedAround a minute before totality the clouds broke and the mistiness of the sky seemed to dissolve away. Darkness enveloped us and the corona burst through a thin veil of cloud to huge cheers. Credit: Will Gater

_MG_0481_DxOAs totality progressed a slightly clearer cloud gap appeared revealing the full extent of the streamers within the corona as well as some beautiful, ruby-red prominences. Credit: Will Gater

moon shadow animThis short animation, taken with a GoPro Hero 2, shows the Moon’s shadow racing over our observing site as well as part of the famous 360-degree sunset. Credit: Will Gater

The video below shows the above but in much higher quality and at a slower speed. It compresses about nine minutes’ of time into one minute. Select ‘720pHD’ for best playback.

Solar eclipse montage20032015From the end of totality to the end of the second partial phase (4th contact) we had a mix of beautiful, blue sky and fluffy, broken cloud. This sequence shows the Moon slipping off the solar disc. Credit: Will Gater

IMG_0537webOccasional, heavy rain showers swept across the islands creating stunning rainbows. Credit: Will Gater

After the eclipse we went on a 3-hour sightseeing tour around the islands by coach before heading to Tórshavn for a few hours. Then it was back to the airport to head home.

Screen Shot 2015-03-22 at 13.33.01 copyThe magnificent colours of the sunset as we flew home from the Faroes.

_MG_0580A coda to an exciting 48 hours of eclipse chasing: this was the view that greeted me on my return home to Somerset, the Moon just a day old. Credit: Will Gater

Warning: observing the Sun can be extremely dangerous. Never stare at the Sun with the naked eye and never observe or photograph the Sun using an unfiltered telescope, camera lens, binoculars, camera viewfinder etc. Doing so risks serious damage to your eyes and/or equipment. The only safe way to observe the Sun is with a specialist, certified solar filter, following the instructions of the manufacturer precisely.

Philae’s great leap – landing on Comet 67P

Credit: ESA/ATG medialab; Comet image: ESA/Rosetta/Navcam

Tomorrow ESA’s Philae lander will leave its mothership Rosetta and attempt to land on the surface of Comet 67P/Churyumov-Gerasimenko in what will undoubtedly be one of the most exciting, and nerve wracking, days in the history of space exploration. A few weeks ago I met some of the scientists working with Rosetta and Philae and spoke to them about this great adventure and their hopes for the mission. Here’s a video of my interviews with them:

I’ll be tweeting what’s happening throughout the day tomorrow from about 06:00UT. A few hours after the expected touchdown of Philae I’ll also be joining a live broadcast on the Slooh network, with host Geoff Fox, talking about the events of the day and what the Rosetta mission hopes to find out. You can tune in live from 19:00UT here.

The North West Astronomy Festival & Tour of the Universe

Just a quick heads up to say that I’ll be appearing at two exciting events this month. The first, next weekend, is the 2014 North West Astronomy Festival in Runcorn, Cheshire. I’ll be giving a talk on the Saturday (11 October) about the ‘Secrets of Celestial Light’. Here’s the flyer:

You can get tickets to my talk and the rest of the event – and see the full line-up for the weekend, which includes Damian Peach, Helen Keen and Jon Culshaw – at the festival website here. I’ll also be doing a book signing for the Knowledge Observatory on the Saturday afternoon if you’d like to pick up a copy of The Practical Astronomer or The Night Sky Month by Month.

The second event I’m appearing at this month is a theatre-based astronomy chat show called Tour of the Universe. This exciting new touring production is visiting the Nottingham Playhouse on the 20th of October and I’ll be the special guest of presenters Neil and Jane on the night. Tickets to the show can be booked through the Nottingham Playhouse box office or online here.


Opening the new Chigwell School observatory & science labs

Last Friday I had the tremendous privilege of opening a new observatory and two new science laboratories at Chigwell School in Essex. The telescope housed within the observatory dome is an 8-inch Meade Schmidt-Cassegrain on a German equatorial mount.

It was wonderful to meet such an engaged and enthusiastic group of students, teachers and staff during my visit, and I’m sure that the school has an exciting astronomical future ahead of it. Many thanks to Steve Davis from Chigwell School for the pictures of the day posted below.

5 Preparing to cut the ribbon. Credit: Steve Davis/Chigwell School

unveiling Officially opening the new science wing of the school. Credit: Steve Davis/Chigwell School

Lab 3 One of the new science labs at the school. Credit: Steve Davis/Chigwell School

lectureGiving a talk about the Mars Science Laboratory mission. Credit: Steve Davis/Chigwell School

Alien worlds at the 2014 International Astronomy Show

Image credit: ESO/L. Calçada/Will Gater

I’m delighted to be speaking at this year’s International Astronomy Show, which is being held at the Warwickshire Exhibition Centre on 7-8 June. I’ll be giving my talk ‘Alien worlds – the extraordinary inhabitants of the Milky Way’ at 10am on the Saturday; in it I explore how we’ve discovered nearly 2000 extrasolar planets in our Galaxy and look to the future and what astronomers hope to find in the coming years. Last year’s show was a huge success and it was great to catch up with old friends and meet many new ones too. If you’re an amateur astronomer in the UK, this is one event you won’t want to miss.

The Gadget Show – astronomy apps and telescope tech

Back in December I spent a fun evening filming with the team from The Gadget Show in the spectacular ruins of Llanthony Priory, in Wales. We filmed a segment for the last episode in series 19, which aired on Monday, about astronomy apps and amateur telescopes. If you’re in the UK and you missed the broadcast you can watch it again by following this link to The Gadget Show video player.

Northern Lights over the UK — 27 February 2014

Last night, following a coronal mass ejection impact, the auroral oval shifted south enough for the Northern Lights to be visible from southern England. Having watched the POES plot get angrier and angrier during the course of the early evening and with the IMF stubbornly south, I decided to jump in my car and drive out of Bristol.

I headed a little way east, to avoid an oncoming cloud front, and found a place to park just northeast of the Bath junction of the M4. As I got out of the car it was clear there was a diffuse glow hugging the northern horizon and every now and then I saw a faint ray appear above it and then dissolve away. No colour was visible to the naked eye though. Thinking (and hoping!) this might be an aurora, and not a trick of the distant light pollution, I set up my DSLR camera and opened the shutter for 20 seconds.

The following images are what I recorded over about ten minutes, after which the sky hazed up considerably and I decided to go home.

Please note that all the images are copyrighted. Clicking on the image will take you to a larger version.






The asteroid with a surprising tale

With the Geminid meteor shower reaching its peak this weekend – as the Earth passes through the debris trail left by the asteroid Phaethon – here’s an interview I did at EPSC 2013 with Professor David Jewitt about his discovery of the rocky body’s unusual behaviour.

(3200) Phaethon is responsible for the Geminid meteor shower (illustration). Credit: Will Gater

What prompted you to study Phaethon?

We were interested in the Geminid meteoroid stream and where the Geminid meteors come from. When the parent of the Geminid meteors, (3200) Phaethon, was discovered and found to be an asteroid it was interesting to ask why would an asteroid produce dust particles. Phaethon was identified in 1983, but until recently it showed no evidence of any strange behaviour. It just looked like an asteroid, which it is, but it didn’t seem to produce any material or show any obvious mechanism for producing dust. The breakthrough was to use a solar telescope [STEREO] to look at it when it’s near the Sun, when it’s very very hot, instead of using a big night-time telescope when you tend to look away from the Sun. And apparently Phaethon is active when it’s near to the Sun but not far away from it.

Artist’s impression of one of the STEREO spacecraft. Credit: NASA/Goddard Space Flight Center Conceptual Image Lab

So these were relatively recent observations?

Yeah, they were taken with a couple of spacecraft [STEREO A and B] that look at the Sun all the time. Phaethon just happens to pass through their fields of view. It’s been doing that for some years, but we just started to look at the data recently and we found this kind of interesting result. We took the individual images from STEREO and we shifted them and added them together, basically to build up the signal to noise and to make a kind of super image with all of the motion removed. Then we could see the elongation [of the tail] pretty clearly.

And that tail only emerges around the time when Phaethon is close to the Sun?

Yeah, when Phaethon is at its closest to the Sun – 0.14AU, so it’s really close.

Phaethon’s elongated tail appears in the processed STEREO images. Credit: Jewitt, Li, Agarwal/NASA/STEREO

Is the tail material that you’ve detected around Phaethon responsible for the Geminid meteors?

The particles that we see are small and we can tell that because they are pushed very strongly by radiation pressure from the Sun. Radiation pressure is very weak but it can accelerate these dust particles strongly. That’s only possible if they are really tiny, like a thousandth of a millimetre. But the rocks that make the meteors that you can see at night time are more like a millimetre in size so they are individually much bigger than the ones that we see. But on the other hand it’s quite possible, in fact likely, that they are there [in Phaethon’s tail]. You have a distribution of particles sizes – lots and lots of little tiny ones and not so many big ones. The big ones cause the meteors but if you’re just looking at reflected light it comes mostly from the small ones. So we naturally detect the small ones.

So in amongst the small particles you’ve seen there must be bigger ones?

Right, and so the issue is can we go the next step which is to find those bigger guys and prove that those are the Geminid meteoroids being produced now. That would answer the question “is Phaethon still producing the Geminid meteoroids?” Or was there some historical event that was like an impulsive explosion of stuff that came out and that made this ring of debris that the Earth goes through every year. Or is it an active process and this body is continuing to decay.

How can we see those larger particles?

We can’t see them with the solar observing spacecraft, we’ll have to use night time telescopes. We have to see Phaethon in a dark sky and try to see these comparatively rare big particles just by looking very carefully at night time with some big telescope somewhere.

What’s the mechanism releasing the small particles?

We think they’re just being fractured off the surface because the surface is so hot. If you take a rock and heat it up it’s going to expand; a typical rock is made of little grains of different minerals and they’ll all expand at slightly different rates. So if you just heat up a rock it will tend to fracture itself because one part is going to expand more than the other. And when it fractures some of the energy of the expansion goes into the kinetic energy of the fragments. So we think they’re almost like popcorn, bursting on the surface of the object and popping off. And as soon as they leap off the surface then this weak pressure from sunlight can blow them away into a tail.

How long is the tail?

The piece that we see is 350,000km long and it appears in one day. So it goes from nothing to 350,000km in one day. To get up to that speed in such a short time you need a big acceleration. And that’s how we infer the particle size – they have to be small and light to be accelerated quickly to go into the tail.

How hot does Phaethon get when it’s close to the Sun?

At midday on the surface of Phaethon with the Sun directly overhead you have the peak temperature, which is about 1000K [over 700°C]. We know that if you take rocks that we find on the Earth and heat them up to those same temperatures they do crack. Some rocks contain water and they dry out, shrink and crack at temperatures even lower than that.

And that’s hot enough to rule out water-ice helping form the tail?

Yeah. There’s no way to keep water ice at the surface – it sublimates so quickly.

Finally, you’ve also ruled out the tail being a sodium tail. Why’s that?

Well if you look at comets, there are some that go close to the Sun. Some of those comets show a sodium tail. The sodium seems to come from rocks; it is boiled out and gets blown away, making a distinct sodium tail. So I thought maybe that could be the case also for Phaethon. But, in fact, it can’t be because we have a filter on the camera that excludes light from sodium so we couldn’t, even if it were there, see it.

You can read the paper announcing the discovery of Phaethon’s tail here: