More staggering stories of super science!

The latest Astronotes is off to the printers. You have a week to prepare yourselves for some super science!

Scientists explore the ultimate secrets of matter! Tracy McConnell reveals the truth in LHC Update.

A force from outer space is sucking our very oceans skyward! Sinead McNicholl tells the frightening story in The Moon and the tides.

A perverse experiment imprisons six men in a metal box for 500 days! Martina Redpath recounts the unbelievable tale in Red Square to Red Planet.

Meddling scientists transplant horse's navel to princess' forehead! Mary Bulman has the shocking details in September Night Sky.

The Universe is bent claims top prof! as reported by Colin Johnston in Still Impossible!

Genuine photo of extraterrestrial visitor! leaked by Tracy McConnell as Image of the Month

Don't say I didn't warn you!

(Image via

Four ALMA antennas on the Chajnantor plain

ESO - alma4anttimelapse2 - Four ALMA antennas on the Chajnantor plain

ALMA is an amazing project, we'll be covering it in detail in Astronotes soon.

Carnival of Space No 168

Good news everyone! There's a new Carnival of Space hosted by the Weird Science blog. Pop over there and join the fun!

(Image Credit: Comedy Central via )

Asteroid Discovery From 1980 - 2010

A fantastic and thought-provoking animation adding asteroids to the Solar System as they are discovered.

(Thanks to Will Gater for sharing this)

That's no star!

Judging by all the enquiries I am getting this week, many of you are seeing a bright star in the eastern sky. This is not a star, especially not the star of Bethlehem, rather it is the mighty planet Jupiter.

Jupiter is the fifth planet from the Sun and by far the largest within the Solar System. It orbits at an average distance of 778 million km from the Sun, about five times as far from the Sun as Earth. As it is so far from us, it takes Jupiter’s light a significant time to reach us –so when you see Jupiter you are seeing it as it was 35-52 minutes in the past. Jupiter is huge, its diameter is over 142 000 km (compared to Earth’s 12 756 km). It is composed of a relatively small rocky core, surrounded by a layer of solid metallic hydrogen (a material which does not exist on Earth), covered by liquid hydrogen. Above this layer is a stormy atmosphere of mainly hydrogen with some helium and very slight traces of other materials. These other traces are enough to colour Jupiter’s turbulent cloud tops in a range of yellow and brown tones. Three times in the past year Jupiter has been hit by asteroid and amateur astronomers have observed the vast explosions.

It is well worth using a pair of binoculars or telescope to view Jupiter, as it can be a magnificent sight. The planet will be clearly visible as a slightly flattened yellowish disc. If your hands are steady enough (or you use a tripod) you will probably also see the streaks of coloured clouds running across the planet.

Jupiter has at least 63 moons. The four largest (Io, Europa, Ganymede and Callisto) are collectively called the Gallilean satellites and are easily visible through small telescopes or binoculars as brilliant points of light in a neat line around the planet. If you watch over several nights their movement as they orbit Jupiter will be apparent.

The image above, made with Stellarium software (freely available from our Free Stuff page), shows the sky about 10.30pm BST from Armagh. Jupiter (marked with a cross) is below the Moon.

So there you are, go out tonight and see a planet a thousand times as massive as the Earth!

Animation of the planetary system around Sun-like star HD 10180 (artist’s impression)

ESO - eso1035b - Animation of the planetary system around Sun-like star HD 10180 (artist’s impression)

The title says it all really.

One curious question I have is, now we have almost 500 known exoplanets how come so few science fiction stories are set in these real locations? (Allen Steele's Coyote series is the only example I can think of). Failure of nerve, lack of research or lack of interest?

(Thanks to Robert Hill of NISO for the link to this animation)

The Light Fantastic

Before the modern era of technological astronomy, to know anything about the Universe beyond our planet we relied on light. We had to see planets, stars, and so on, to know they existed. Astronomy was based entirely on light.

What then is light? This is a question which occupied the minds of some of the greatest scientists. Many early ideas have been discarded, now we have a good idea of the nature of light. Historically the two rival ideas were that light was either a stream of tiny bullet-like particles or a wave wobbling its way through space.

The light we see (visible light which is not the tautology it sounds) is only part of the electromagnetic spectrum, a great sweep of radiations which also includes radio, infra-red, ultra-violet, x-rays and gamma rays. This is the celebrated Electromagnetic Spectrum. Unlike sound, all electromagnetic radiation can travel through completely empty space at about 300 000 km/s (186 000 miles per second), the fastest speed possible. Any electromagnetic radiation does indeed travel in the form of waves. The obvious question is “waves in what?” and the least-complicated but rather unsatisfying answer is “in itself”. An electromagnetic (EM) wave is a pair of co-joined electric and magnetic waves oscillating together through space. Hold this image in your mind- I’m going to flatly contradict it in a moment or two.

Every EM wave has a frequency (how often per second it wobbles) and a wavelength (how far it travels between wobbles). These are linked; a high frequency EM wave will have a short wavelength while a low frequency wave will have a long wavelength. For example, the waves carrying the data to your computer in a domestic wireless network may be buzzing away more than two billion times per second (2GHz) and have wavelengths about 15 cm (6 inches) long. (Try multiplying two billion by 15cm, you will get a speed in cm/s; turn it into km/s. Does the answer look familiar?) In contrast, a broadcast radio station may transmit the news and music at 96 MHz (i.e. 96 million oscillations per second) in waves 3m or so long. (Try that multiplication thing again.)

The EM spectrum discriminates radiations by their wavelength or frequencies. Let us take a walk through the spectrum. Radio waves are relatively long wavelength (the Extremely Low Frequency signals used to communicate with submerged submarines are 3000-6000 km long!). Shorter wavelength (say 1m to 1 mm) radio waves are termed microwaves (look at the back of your microwave oven; you ought to find the microwave frequency in MHz somewhere), shorter still waves include the infra-red bands and then in the middle of the spectrum we have the familiar ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet) which Isaac Newton showed to make up white light. This is the ‘proper’ light we are all familiar with, most of the Sun’s radiation falls in this comparatively narrow band of wavelengths. Green light (in the centre of the visible band) has a wavelength of about 0.00055mm (about 1/10 the diameter of a red blood cell). Moving beyond violet, we pass into the invisible ultra-violet, as the waves shorten further we enter the realm of X-rays and gamma rays.

By the start of the Twentieth Century it was certain that light was a wave. Many experiments confirmed it. Then some experiments indicated that a beam of light shining on a metal surface could knock electrons out of the metal. This was inexplicable by the wave theory, in fact it suggested strongly that light was actually a stream of tiny particles after all. It was for pointing out this explanation that Einstein was awarded his Nobel Prize rather than his better-known theories of Relativity. The particles were even named photons. So light is either a wave or light is a stream of particles. Which is the right answer? Again the answer, derived from quantum mechanics (a can of worms I have no intention of delving into here) seems an unsatisfying cop-out. Light is both at the same time. Weird though this may seem, something can be a wave and particle at once (although this can only be observed on very small scales). Astronomers are accustomed to this. You will read about, say, a telescope designed to focus gamma ray wavelengths on to a detector which counts the number of photons it picks up.

For most of the last century, astronomy has been scanning the Universe in ever more exotic wavelengths. As a result we have found pulsars, black holes, starforming regions, and Kuiper Belt object and much more. What will we find next?

(This article originally appeared in the March 2008 issue of Astronotes. )

Image Credit: NASA

The light and the dark

In, say 1975, there was only one kind of 'stuff' in the Universe, matter made of protons and neutrons. By 1985 there was a consensus that this was not enough, the gravity of the stars in galaxies was not sufficient to hold them together. Something else was there, vast, mysterious and imperceptible, only observable by its effects on its surroundings. Imagine HG Wells 'Invisible Man' moving unseen through a room until he knocks over a vase. There was much more of this dark matter out there than stuff we could experience directly.

By 2005 it was clear that there was more going on out there. Another unseen and unknown something was pushing the galaxies apart. This is dark energy, a force which permeates all space. Astonishingly weak, dark energy can still move galaxies given aeons of time.

No one knows what dark energy and dark matter are; researchers study the light of far off galaxies to see how these elusive quantities effect them. The image shows the galaxy cluster Abell 1689, light from distant galaxies is bent by the gravity from galaxies closer to us but on the same line of sight creating a text-book example of a gravitational lens. This gravity is mainly, we now know, exerted by the dark matter in the galaxies (the blue fuzz in the image is not real, it is a superimposed map of matter distribution). At the same time, however, dark energy is pushing the galaxies apart adding a subtle additional distortion to this ancient light.

Dark matter and dark energy are utter mysteries today but so were electricity, magnetism and radioactive decay once. In some future time we will understand dark energy and matter just as well. Dare I speculate that one day we shall apply them? (I'm holding out for spindizzies myself.)

Image credit: NASA, ESA, E. Jullo (JPL/LAM), P. Natarajan (Yale) and J-P. Kneib (LAM).

Carnival of Space No 167

Sometimes three isn't enough; let's add a Fourth Law of Robotics, how about

4. A robot shall visit the Carnival of Space every 604800 seconds and follow all the quality links contained therein as long as this does not conflict with the First, Second or Third Laws.

This week's Carnival is hosted by the spacetweepsociety, jump on over, there's lots to see and do!

Cosmic Coelacanths

We all love bright and showy spiral galaxies! So much so, that we tend to overlook the elliptical galaxies which make up about 30% of the galaxies out there.

Smaller than spiral galaxies, elliptical galaxies may be full of stellar living fossils, surviving virtually unchanged from an older cosmic era. Their stars are mainly old reddish stars, rather than the young blue-white star which blaze in the arms of spiral galaxies. This aging population is because there an initial frenzy of star formation in the galaxies' early days this soon fizzled out. The interstellar matter which provided the raw material for new generations of stars in galaxies like our own is scarce in elliptical galaxies. This absence of gas and dust explains an elliptical galaxy's spheroidal shape; there is nothing to flatten the orbits of the stars into a single plane of rotation.

Elliptical galaxies are smaller than spiral galaxies, roughly spherical and full of old stars. You may be thinking that this sounds familiar and you would be correct. Elliptical galaxies are very similar to the cores of spiral galaxies. This may be exactly what they are. We know that galaxies interact and even collide. Theories suggest that this processed can rip the arms clean off spiral galaxies, leaving behind a disrupted core which we see as an elliptical galaxy. What happens next? Perhaps the galaxy will accumulate gas and dust from the intergalactic medium as it wanders through the void, building new spiral arms in the process. Alternatively it will simply drift on forever as a cosmic coelacanth, reminding observers of the Universe's earlier days.

The image (click on it to enlarge it) shows elliptical galaxy NGC 4696 in the Centaurus Galaxy Cluster, notable for the 30 000 light year long streak of dust running across it. NGC 4696 is some 155 million light years from our own galaxy, so we are seeing it with light which left the galaxy in Earth's early Cretaceous Period, about the time the first mammals were scurying between dinosaurs' feet.

Image Credit: ESA/Hubble and NASA

Latest Armagh Planetarium Astronomy Courses

Astronomy Courses

These are coming soon and I'm really looking forward to presenting them. Book now to avoid disappointment!

The Carnival of Space No 166

The Carnival of Space: Issue #166

The latest Carnival of Space is here already, hosted by Check it out, there's lots to see.

Three easy to spot stars

Around this time of year, go outside after 10pm on a clear night and look at the sky. Even if it is not quite dark a bright star will be visible in the south. This is Vega, the third brightest star in our sky (only Sirius and Arcturus are brighter). If you look a little more you will see two more bright stars, these are Deneb and Altair. Together with Vega they form a large triangle with the point downwards. This has been known as the Summer Triangle for a century or more. The three stars are members of three different constellations and as it gets darker you will be able to see more of their fellow stars. Deneb is the tail of Cygnus (the Swan), Altair is in Aquila (the Eagle) and Vega is in Lyra (the Lyre). The Summer Triangle is not actually a constellation itself, just a nice handy grouping of stars, astronomers call these asterisms.

What about the stars themselves? Well, all three are brilliant white A class stars, to our eyes Vega is the brightest, next brightest is Altair and Deneb is the faintest. However, although it looks the dimmest, Deneb is actually by far and away the biggest and brightest of the three stars. In fact, it is one of the brightest stars in the night sky. So why does it look relatively dim compared to Altair and Vega? Deneb is thousands of light years from us, much, much further away than the other two stars which are very close to us in astronomical terms. Altair is located just 17 light years away from Earth, so it is one of the closest stars visible to the naked eye. Vega is another near neighbour of ours, a mere 25.4 light years from the Sun.

Altair is just a little bigger than the Sun but is spinning very, very fast. The star rotates once around its axis every 6.5 hours (our Sun takes more than 25 days). As a result Altair's shape is extremely flattened, it you were close enough you would see that is not a sphere like the Sun but shaped more like a thick discus. If its rotation rate was much faster it would have been pulled apart.

Vega is twice as big as our Sun and about fifty times as bright, it spins very quickly too, but not as fast as Altair. Vega is very interesting to astronomers, as in 1983 scientists using a satellite called IRAS unexpectedly discovered Vega is surrounded by a shell of dust and ice bigger than our Solar System. Nobody is sure why this material is there. Some scientists suggest that it is evidence for huge comets orbiting the star, others say it is material forming into new planets or even debris left over from colliding planets!

The stars of the Summer Triangle are easy to see and individually fascinating. Why not point them out to your friends before exploring the other wonders of the summer sky?

Image credit: NASA, ESA, A. Fujii

Oh no, not again!

Summer 2010 isn't over yet but already Hollywood is planning next year's offensive on our wallets. One planned blockbuster for summer 2011 is Battle:LA in which extraterrestrial invaders spread alarm and dismay in southern California (the image is from the film's viral marketing campaign). An expensive production starring Aaron Eckhart and Michelle Rodriguez (whose character based on past form probably will not survive to the end of the movie), the film is said to feature realistic and gritty combat sequences and well-thought out alien designs.

Alas, one aspect of the script is not well-thought out. Script writer Jonathan Liebesman has explained the aliens' motive behind their anti-social behaviour "Earth is 70 percent water. The aliens in our movie use water for may different things, so they are here for those natural resources." (Quote from

What can I say but "Dumb!Dumb!Dumb!"(That sound you hear is me banging my head on the desk.)

Imagine you are leading an alien water-stealing mission to our Solar System. Do you
a. Go to Earth, beat up the natives and take some of their water or
b. Go to Saturn where there is about a hundred thousand trillion tonnes of pure water in the form of nice ice cubes in the planet's rings ready for the taking. And there's a pretty view too. And don't get me started on Enceladus, Mimas, Dione and the other 60 or so Saturnian moons. Or the other gas giant satellites...

It's been done before, the invaders in the original V (1983-85) came for our water, and in Caretaker (1995), the pilot for Star Trek: Voyager (yes I watched it, somebody had to) the quasi-evil Kazons were crossing interstellar space to steal the H2O from the home planet of the bland and dim-witted Ocampa.

If you have a starship, space is full of water. Only aliens and scriptwriters don't get that!

Carnival of Space No 165

The latest Carnival of Space has materialised over at Cumbrian Sky. Check it out; it really is bigger on the inside than the outside!

(The awesome Dr Who/Simpsons mashup is courtesy of the Springfieldpunx blog.)

ESO - eso1032 - Seeing a Stellar Explosion in 3D

ESO - eso1032 - Seeing a Stellar Explosion in 3D

A fascinating story about the most violent explosions in the Universe. It's nice to see a researcher from QUB is prominent in this field.