Royal Observatory Greenwich blog
New views of the Aurora – from Sweden and Saturn
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September 24th, 2010

Many people have remarked on the two beautiful pictures of
the Aurora Borealis or Northern Lights which feature in our current Astronomy Photographer of the Year exhibition. Anyone who’s been lucky
enough to see the aurora for themselves will know what a beautiful spectacle it
can be, so it’s not surprising that we had quite a few photos of it entered
into this year’s competition (which made the judging very tricky).

Earth’s aurorae are ultimately caused by the Solar Wind, the stream of
energetic particles emitted by the Sun. Funnelled down towards the North and
South Poles by the our planet’s magnetic field, these particles strike
molecules of air high up in the atmosphere, causing them to glow and
produce a shimmering display of lights. Because of this, aurorae are most
commonly observed at high northern and southern latitudes and indeed both of the
award-winning aurora photos this year were taken close to the Arctic Circle:
one from Canada and one from Norway.

At the Astronomy Photographer awards ceremony on September 9th I
found myself chatting to photographer Max Alexander
 who mentioned that some years ago he’d taken a
picture of an unusual aurora while working in Sweden.
I was very curious to see his photo and Max has kindly agreed to let
us post it here on the ROG blog. 

Max Alexander aurora

Max says: 


“I took this photograph of the Northern Lights while on assignment for
a book publisher to photograph the Ice Hotel, in Kiruna, Northern
Sweden
, a perfect latitude from which to view them. 

“After several unsuccessful nights looking up, I met a couple who
invited me to their wedding ceremony in the adjacent Ice Chapel, and subsequent
reception. Every so often, I looked out of the window to see if the Northern
Lights would appear – and then they did, in all their breathtaking glory. I
convinced the wedding party to go out into the freezing arctic air, and they
were not disappointed. For twenty minutes there were audible gasps, as the
aurora borealis first snaked slowly, then rapidly danced across the sky in
giant and dazzling green arcs. I set my camera up quickly on my tripod, opened
up the aperture fully on a wide-angle lens, and then made a series of 15 second
exposures. Technically not difficult, I just needed to nail the composition.

“Back in London,
The Independent used one of those photographs on the cover of their magazine,
for a piece about Norwegian scientist Kristian Birkeland, the first person
to provide a scientific explanation of aurorae. I also contacted the University ofLondon
Observatory
 about
what caused this phenomenon and from that conversation I ended up doing a
diploma in astronomy at UCL, which in turn led me to take a series of
photographs on astronomy in the UK,
entitled Explorers of the Universe.

“I have reliably been told that this is a very rare photograph of the
intertwining twister effect that you can see and Patrick Moore is the only
person I have asked who has seen it in a photograph before. 
Mike Lockwood, a solar-terrestrial
scientist at theUniversity of Southampton, explained to me
that the aurora usually occurs in extended, curtain-like sheets. However,
sometimes, as here, it is restricted to a small rope-like form. The currents
flowing down the centre of such “auroral filaments” cause the
surrounding magnetic field to twist up into the helical forms that can be seen
here. The direction of the twist in this image shows that the dominant current
was upward.  In other cases the current can be downward and the twist
would then be in the opposite direction.

“By the way, the couple who got married have since become good friends of
mine, and the pictures of the Northern Lights are part of their wedding
photographs.”

As the Sun continues to move into a more active phase of its eleven-year
cycle we can expect to see more auroral displays as increased solar activity
launches storms of particles in our direction. The Royal Observatory has a long
history of observing activity on the Sun and our Solar Stormwatch citizen science project allows members
of the public to help continue that research in the 21st Century (and also links to a great gallery of aurora images).

PIA13402-640


Finally, it’s worth pointing out that the Northern
and Southern Lights are not just an Earthly phenomenon, as these spectacular
new images and movies of
 aurorae flickering around the poles of Saturn show. The
data come from NASA’s
 Cassini spacecraft and we’re
very pleased that
 Tom Stallard and his
team at the University of Leicester have allowed us to incorporate some of the
images into the Saturn option of our Solar System planetarium show
 Meet the Neighbours. So if you’d like to see
the Saturnian aurora in all its glory up on the dome come along to the show and
vote for Saturn as your destination.

Farewell Halley, hello Astrophotographers
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September 9th, 2010

It’s all change in our temporary exhibitions gallery as we take down our summer exhibition Halley’s Holiday and install a new one showcasing the winners of the 2010 Astronomy Photographer of the Year Competition.

Halley’s Holiday was a special exhibition for children to celebrate the 350th anniversary of the Royal Society, the UK’s national academy of science. The Royal Society is fifteen years older than the Royal Observatory and the two institutions have been closely associated for much of their history.

In the exhibition Halley the Space Shuttle took visitors on a tour of the Solar System, showing them beautiful views and highlighting some amazing facts about each of the planets. At the end visitors had the chance to vote for the planet they’d most like to take a holiday on. The votes are now in and the results are as follows:

Mercury: 287,582
Venus: 244,820
Earth: 449,643
Mars: 288,851
Jupiter: 239,953
Saturn: 261,202
Uranus: 278,791
Neptune: 368,119

I was very pleased to see that the Earth topped the poll as it’s (for now at least) my own favorite planet in the Universe. Like me, maybe our visitors were swayed by the fact that it’s the only place in the Solar System where you could enjoy your holiday without a space suit. I’m not sure why Jupiter got the least number of votes but perhaps it had something to do with its unpredictable clouds, its tendency to attract asteroids and a hurricane-force storm the size of the Earth which has been raging for several centuries. Who knows? Thanks anyway to everyone who voted.

The Astronomy Photographer of the Year exhibition begins at the ROG tomorrow, September 10th, and is completely free. We’ll be posting live updates from our brand new Twitter account for the Astronomy team – @ROGAstronomers; find out who the winners are before the exhibition opens by following this account or the hashtag #astrophoto10.

Mission to Hubble
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May 11th, 2009

HSTshuttle.jpg

This is an exciting day for astronomy as the Space Shuttle Atlantis and its crew of seven astronauts prepare to launch into orbit and rendezvous with the Hubble Space Telescope. Hubble has been in orbit for 19 years now, sending back a constant stream of images and data which have revolutionized almost every field of astronomy. But almost two decades in space have taken their toll and the telescope is in desperate need of refurbishment.

Having matched orbits with Hubble 560km above the Earth, Atlantis will grasp the bus-sized telescope with its robotic arm and pull it into the shuttle’s cargo bay where the astronauts can carry out their repairs and upgrades. This will be no easy task and will require no less than five gruelling spacewalks – uncomfortable hours spent in the confines of a spacesuit trying to manoeuvre phone-booth sized pieces of equipment into position and perform precision tasks whilst wearing thick protective gloves.

The shuttle crew have been in intensive training for this mission for months but even so the trip is not without personal risk. Since the tragic loss of the shuttle Columbia in 2003 NASA has only allowed its shuttles to venture into orbits from which they could reach the International Space Station in an emergency. Hubble is 200km higher than the ISS and the shuttle doesn’t carry enough fuel to reach it should anything go wrong but, in recognition of Hubble’s scientific importance, NASA have waived this rule for the current mission. Instead Atlantis’ sister craft Endeavour will be waiting on the launch pad in case a rescue mission is needed.

If all goes well, Hubble will have two brand new state-of-the-art instruments fitted, bringing it bang up to date with 21st Century technology and expanding its science capabilities enormously. The Atlantis crew will also repair three malfunctioning instruments and replace other old and failing equipment. The refurbished Hubble should enjoy a healthy old age lasting well into the next decade and keeping astronomers busy until the launch of its successor, the James Webb Space Telescope, in 2013.