Jupiter is the most prominent object to see in the night sky during October, rising just before sunset it is visible throughout the entire night! Jupiter can be found to the East just after sunset, and due to the rotation of the Earth, it appears dues South at midnight. If you go somewhere really dark, you will be able to see your own shadow cast by Jupiter! I've seen that on a few occasions.
Take a look through binoculars or a small telescope, and see if you can spot the four bright Galilean moons that orbit around Jupiter. Our Moon is conveniently close to Jupiter in the night sky on the 19th & 20th of October, acting as a useful guide. The photo' below shows how close they were together last month.
The Moon begins its appear in the evening sky as a thin crescent on the 8th – a beautiful sight in the evening sky. The Moon reaches full Moon, when it is on the opposite side of the sky to the Sun, on the 23rd.
The summer triangle is still visible in October, despite its name, high in the South at 7pm. The three stars that make up the triangle are Vega, Altair & Deneb. Vega is the brightest of the three stars, and there maybe a planet like Jupiter in orbit around Vega (see the wikipeida entry). Altair is interesting because it rotates in just 7 hours! And Deneb is actually one of the brightest stars we know of – some 250,000 times bright than the Sun! The reason it looks fainter than Vega is only because it is much further away – Deneb is some 100 times further away than Vega. If Deneb was as close as Vega, it would be as bright as the Moon!
Mars and Regulus are just a degree apart in tonight's night sky. Their contrasting colours are a beautiful sight - so do take a look! But be quick, as Mars is orbiting the Sun, it is moving around the sky, and so it will only be close to Regulus for the next few nights.
Here are a couple of photographs that I took last night with a zoom lens. In the night sky, the two are separated by the width of a few of your fingers at arms length!
Summer begins this month, and because the Sun is not setting until after 9pm, darkness does not begin until 10pm. But there is plenty to see this month if you are willing to stay up a bit later.
As soon as it begins to get a bit dark, look towards the sunset, and by 10pm you will be able to see the planet Venus, very low in the sky. It looks a bit like an aircraft coming in to land… but if it is still there 10 minutes later, and hasn’t landed, then you have found Venus!
Look to the left of Venus, and slightly above it, and you will notice a red object – the planet Mars. During the month, Mars is close to the star Regulus, at equal brightness but not as red. On the 6th of June, Mars passes only 1 degree away from Regulus as it moves around the Sun and so moves around the sky.
Then look to the top left of Mars, and you have Saturn, which appears to be quite bright and slightly yellow in colour.
Venus is setting at about 11.30pm, with Mars following it an hour later, and then Saturn is setting an hour after that.
The positions of the planets can be seen in this movie below.
If you now look in the other direction towards the stars rising in the South-East (see graphic below, set at 22:30BST), you will see three bright stars – Deneb, Vega and Altair. Those three stars are known as the summer triangle of stars, and are fascinating in their own right. Vega has a dusty disk around it and maybe a planet; Altair rotates in just 7 hours, making it bulge around its equator; and Deneb is one of the brightest stars we know of. Deneb is over a 100 times further away than both Vega and Altair, but it looks equally bright because it is so big – at least 200 times the diameter of the Sun! If Deneb was as close as Altair, it would be almost as bright as the full Moon!
I will be writing more about what can be seen in this patch of sky over the coming months, as the Earth moves around the Sun to get a better look at this patch of the night sky.
Now is a great time to feel that you are part of the solar system. Venus, Mars, Saturn and the Moon are all visible in the evening sky. As you can see in the photograph I took a few nights ago (below), all the planets lie along a line called the ecliptic, which goes to show just how flat our solar system is. (Just hover your mouse over the image for labels)
Our solar system is like a big flat pancake! Imagine the Earth sitting on that pancake, along with the rest of the planets. The grid marks where that pancake (the flat plane of our solar system) goes out into space, and so where all the planets can be found. The constellations of Leo (top left) and Gemini (bottom right) are also shown.
The following animation shows just how it looks from the ground and from above the solar system.
This month is a great month for planets! If you go out on a dark night you can see and feel for yourself how we are part of the solar system.
Look low in the west, half an hour after sunset, you can see Venus - the brightest object in the sky after the Sun and Moon. Now wave your arms around in an arc going from Venus low in the west, over the south and then towards the south-east, and you will bump into two more planets in the night sky – the red planet Mars, and Saturn which is yellowish in colour.
Ancient people knew of the planets Mercury, Venus, Mars, Jupiter and Saturn because they are all so easy to see with your own eyes - they are all bright objects that can even be seen through our light polluted skies. However, Mercury cannot be seen at the moment since it is too close to the Sun (Mercury passed between us and the Sun on the 28th of April), and Jupiter is above the morning side of the Earth, and so we can only see Jupiter very early in the morning.
But do take a look for Venus, Mars and Saturn, the bright planets in this months evening sky. They are forming a beautiful arc across the night sky, which really highlights that we live close to the centre of the very flat solar system.
The International Space Station will be visible flying over the UK for another week (before it starts flying over in daytime), so do take a look... and don't forget to wave at the six astronauts currently on board as they fly overhead!
The space station orbits the Earth every 96 minutes, but for us to clearly see it, the ISS needs to fly over at dawn and dusk. We see the space station thanks to sunlight reflecting off it, mainly off the huge solar panels the size of a football field. If it flies overhead in the daytime, the sky is too bright for us to see it; and if it flies over head at night, then the station is in the shadow of the Earth, and so we can't see any reflected sunlight.
For the next week, we are lucky - on some nights we can see the ISS fly overhead on two consecutive orbits, one 96 minutes after the other.
Over the next few weeks, the International Space Station can be easily seen flying over the UK. Its solar panels are the size of a football field, allowing the space station to be easily seen from the ground as they reflect plenty of sunlight.
Times when the space station can be seen for the next week are below, or at either SpaceWeather.com, or on Heavens-Above.com. Although these times are exact for Brighton, the times will be within half a minute of these times for anywhere in the UK, or you can simply follow those links and type in a new location.
The table below gives the time and position of the International Space Station as it starts to fly over the UK, reaches the maximum height and the time when it disappears (ends).
In the table, Alt. refers to the altitude of the space craft as it flies overhead (90° is directly overhead, and 0° is the horizon); Az. is the Azimuth, or direction, of where it will be at the given time (0° being North, 90°: is East, 180° is South and 270° is West).
Speaker: Professor Steven Cowley, Director of Culham Laboratory.
Date & Time: 7pm, Tuesday 4th of May, 2010
Location: Pevensey 1, theatre 1A7, University of Sussex
In a decade, the international fusion experiment ITER will start operating in the south of France. This historic experiment will generate up to 500 megawatts of fusion power and provide a proof of principle for fusion energy. Fusion has the potential to provide a large fraction of our energy for millions of years. In this talk, Steven will describe the scientific progress in fusion, from Sir Arthur Stanley Eddington's prophetic predictions in 1920 to the remarkable results that have lead to ITER, and the challenging problems that must be solved to make fusion power a commercial option.
During the course of a year, as the Earth orbits the Sun, the position and timing of the Sun set changes. Below are two photographs, taken exactly a day apart and then superimposed on one another, that illustrate just how much it changes!
Remember! Never look at the sun directly, and it can result in blindness.
It is now impossible to see the planet Mercury in the evening... Until it orbits around the Sun again. But I did manage to take the following photograph last Thursday, of a beautiful alignment of the Moon, Mercury and Venus.
Mercury orbits the Sun in just 88 days, and over the next week, you can see how quickly it moves in relation to Venus.
I took the photograph to the left on Monday the 12th April, at about 9pm, and you can see Mercury and Venus side by side (Venus is the bright object; Mercury the fainter object to the right of the image just slightly lower then Venus in the evening sky). But over the next week, as Mercury orbits around the Sun, it will rapidly move away from Venus to be in line with the Sun on the 28th of April.
So, if you want to see Mercury for yourself, the next few days would be a good time to look...
The next few weeks are an ideal time to see Mercury & Venus together in the evening sky.
Mercury is always a difficult planet to find. It is the closest planet to the Sun, and so it always remains close to the Sun in the sky, usually totally hidden in the Sun's glare. But at the beginning of April (as the simulation below shows), Mercury gets to its Greatest Eastern Elongation, meaning that it is as far away eastwards of the Sun as it is ever going to get, and so it is the best time to see Mercury in the evening sky.
So wait for the Sun to set, and then go out and see if you can see Mercury for yourself! The best days to look are the 15th and 16th of April, when the Moon acts as a useful guide. This will be your best chance to see the elusive Mercury!
Each frame in the simulation above is a view looking west when the Sun is 6 degrees below the horizon (about 40 minutes after sunset) - that's dark enough to see Venus and Mercury, but not so late that they are hidden behind trees. The simulation was done using Stellarium.
Today, the 20th March, the spring equinox occurs at 17:32. That is the time when the Earth is neither tilted towards, or away from, the Sun, giving us an equal length day and night - hence the name, Equinox!
If you are wondering where Jupiter and Mercury are at the moment... they are hiding behind the Sun!
Below is a movie using data from the Lasco C3 insrtument on the NASA/ESA SOHO observatory, during February 2010. SOHO points constantly at the Sun, and so it allows us the see Venus, Jupiter and Mercury following their orbits around the far-side of the Sun.
It begins with Venus leaving the scene towards the left (which is why we can see it now in the evening sky), and then Jupiter moving left to right, and finally Mercury appearing!
Note that Lasco C3 is sensitive to 540nm-640nm wavebands, which is mid-green through to mid-red... so I've changed the usual blue colour to grey-scale (I think true colour would be a yellowish-brown...?).
Note also the 'bleeding' of the bright planets - they are so bright, that electrons over-flow into neighbouring cells on the Lasco-C3 CCDs. Note the the Sun is hidden behind a disk, to ensure that its brightness does not damage the camera.
In January, Venus was on the far side of the Sun and totally hidden in the glare of the Sun.
But now it is back! Take a look in the evening sky for a glimpse of the brightest planet...
Venus will be a prominent member of the night sky throughout the summer until the end of August. If you have a zoom lens on your camera you may be able to just make out the crescent of this planet, which is very obvious with even a small telescope. Our view of Venus' crescent will change over the next few months, as it orbits the Sun. The animation below shows this in more detail.
Venus began 2010 on the opposite side of the solar system to the Earth, which is why we could not see it. By March 2010 (when the Earth is at the 11 O'clock position in this animation), Venus became visible in the evening sky.
By 20 August 2010, Venus will reach its maximum Eastern position from the Sun (when the Earth is at the 5 O'clock position on this animation). And then Venus rapidly "catches up" with the Earth, being between the Earth and the Sun on the 29th October, 2010.
The animation then returns to the beginning of the year to watch how the phase of Venus (what fraction of Venus is illuminated) changes during 2010.
But by October, when Venus is between us and the Sun, we will only be able to see the night-time side of Venus. (Venus will also appear to get larger in size during the course of the year).
To see a satellite, it must fly over head at either dawn or dusk - when it is dark enough for us to see them, but when sunlight can still shine onto the satellite (for instance, if a satellite flies over-head at midnight, it is in the shadow of the Earth for the entire flyby).
Sometimes, a particular satellite will fly over-head at midday when the daylight is too bright; sometimes it might fly over at midnight when it cannot reflect sunlight.
You might have seen satellites flying over-head yourself and just not realised what you are looking at. The rule of thumb is - if it is flashing, it is an aircraft, but if it is at a steady brightness, then you are looking at a satellite!
For the next week, the International Space Station is ideally placed to be seen flying directly over the UK! The approximate dates and times are listed below...
March is one of the best times of the year for astronomy, simply because there is so much to see!
Orion and Taurus – along with all the amazing objects that surround that part of the sky, such as Orion's nebula, Betelgeuse, the Pleiades - are visible in the evening, and as they set by midnight, the summer highlights begin to rise in the east – Hercules, the Great Globular cluster, with Vega and the rest of the summer triangle on their way from the morning sky into the evening sky, signalling that summer is not far away.
We can see both Mars and Saturn throughout the night, with the latter rising at sunset. The Moon glides under Mars on the 25th March, and then passes under Saturn a few days later on the 29th. Both Mars and Saturn are quite bright, so they are easy to spot.
Over the next week, the asteroid Vesta will gracefully slide past the beautiful double star Algieba, in the constellation of Leo the Lion - as shown in the animation below (Vesta is the moving object left of centre; each frame is from the evening of the date shown).
So it has never been so easy to see an asteroid!
To find Vesta, look for the constellation of Leo - easy to spot in the east at 8pm, or by midnight it has reached due south. The bright red planet Mars is also a useful guide, to the top-right of Leo. Leo is easy to identify thanks to the big "backwards question mark" of stars, that forms the head of Leo the lion in ancient mythology.
Then look for Algieba - it forms the neck of the lion, or half way up the question mark. It's easy to see with your own eyes, and if you look through a telescope you can see that it is not just one star, but a beautiful pair of stars, orange and blue. The different colours tell us that these stars are at different temperatures, the blue star being much hotter.
Point your telescope towards Algeiba on the nights of the 14th to the 17th of February, and the asteroid Vesta will be in the field of view. Vesta is on the limit of what you can see without optical aid, so you will need either a very dark site away from light pollution, or binoculars or a small telescope to see it.
More information about Vesta, which orbits the Sun once every 3.6 years, can be found on the Wikipedia. The animation above was produced using the free Setllarium software.
Last week, the University of Sussex hosted the Energy GCSE revision event, a travelling road-show put together by the South-East Physics Network. We had children visiting from Hailsham Community College, The Forest School and Cavendish School.
The event began with experienced school physics teacher Jennifer MacGregor giving an overview of how energy can appear in different forms, and talking about the various ways in which energy can be generated – from coal and nuclear powered stations, to the renewable sources of energy.
Then, it was time for the practical demonstrations! There were twelve demonstrations, covering everything from pumped-storage hydroelectric and harnessing the power of waves, to thermal cameras searching for inefficient buildings and the "disco bike" – two volunteers cycling to generate enough electricity to power a disco!
All these activities were demonstrated to the school students by undergraduate and postgraduate members of the University of Sussex's Physics & Astronomy department.
If you want to know more about future SEPnet GCSE revision events, please see their website at www.sepnet.ac.uk.
If you want to see the sunspots for yourself, make sure you do it safety! There are plenty of safe ways to look the Sun which will not blind you, such as using a solar telescope, or by projecting an image of the Sun onto paper. Never look at the Sun directly, as permanent blindness may result.
The highlight this month is the planet Mars. Easy to spot as a bright red object in the night sky, visible in the east at sunset, moving to the south at midnight, and heading further west in the morning hours. And, because both the Earth and Mars are on the same side of the solar system at the moment we are quite close to Mars, making Mars look brighter in the evening sky, and big when you look through a telescope.
This why there are some fantastic images of Mars being taken recently, including this one from local astro-photographer Pete Lawrence, showing a dust devil that has pasted across the martian south pole (more details at SpaceWeather.com).
By 10pm, the planet Saturn is also rising in the east. The rings of debris that surround this planet are visible through binoculars if you have good eyesight, or easily through a small telescope to the rest of us.
Orion (the hunter), Taurus (the bull) and Canis Major (the great dog) are the dominating constellations this month, with the bright star Sirius forming the nose (or sometimes the collar) of the dog. You should not miss out on looking at the Pleiades or the Orion Nebula through binoculars, and notice how Sirius twinkles due to our turbulent atmosphere.
Today, the 29th of January 2010, Mars reached opposition - this means that Mars is on the opposite side of the sky to the Sun (see the diagram of our solar system at the very bottom). So as the Sun sets in the West tonight, Mars is rising in the East. This also allows us to get great views of Mars, and amateur astronomers around the world have been taken some breath-taking images of the planet - such as the one below, taken by Pete Lawrence here in Sussex.
Do make sure you go outside and take a look at Mars! As soon as it is dark, go outside and look East for a bright red object in the sky - that's Mars!
If you want to see the sunspots for yourself, make sure you do it safety! There are plenty of safe ways to look the Sun which will not blind you, such as using a solar telescope, or by projecting an image of the Sun onto paper.
These images taken by the NASA/ESA SOHO solar observatory on 20-21 January 2010 show a comet falling towards the Sun (from the bottom left).
As you can see, the comet does not come out the other side, so... bye bye comet! It must have been vaporised by the Sun!
Comets fall towards the Sun frequently (in fact, SOHO has seen over 1600!), but it's always fun to guess if the comet will survive and come out the other side, or just be so close that they are vaporised by the Sun!
The Lasco C3 instrument on board SOHO works by hiding the incredibly bright Sun with a disk (the silhouette of the disk is at the centre, and the arm that holds it in place goes off towards the top right). This allows the camera to see the fainter gas being ejected by the Sun, without the bright Sun damaging the camera.
However, even the planet Venus (bottom left of centre) is too bright for the camera! Venus is so bright, that it fills that part of the digital camera chip with electronic charge, and that charge spills over to the neighbouring pixels forming the long horizontal line. (in fact, my pocket digital camera does axactly the same if I point it at the sun)
Note also that there is a lot of noise on the movie. That is due to cosmic rays hitting the Lasco C3 camera - it's a harsh place is space, and there is no atmosphere to protect SOHO from the cosmic rays.
Oh, and why blue? Well, why not! Each camera on-board SOHO is colour-coded with a different colour, so astronomers immediately know what camera took the image.
On Friday, there is a Annular Eclipse of the Sun, from 04:05 GMT, with mid eclipse at 07:07 GMT, and ending at 08:59 GMT... yes, that's in the middle of the night for us here in the UK, so unfortunately, we will not be able to see it at all! (and even when the Sun is visible at the end of the eclipse, the Moon is slightly off to one side as seen from the UK)
The eclipse will be visible from Africa and across India, as show in the map below.
Below is an animation I made from a series of photographs taken during the annular eclipse of 2005. The reason it is an annular, and not total, is that the Moon orbits the Earth not in a circle, but in an ellipse. During this eclipse, the Moon is slightly further away than on average, making it appear slightly smaller, and so too small to cover the Sun completely.
If you do happen to be in the path of the eclipse, do not look at it with your eyes, since you will probably be blinded for life. Instead, use solar glasses, a simple and cheap solar telescope, or just use your hands as a pinhole projector!
We have two evening sky planets that we can see throughout January - Jupiter in the early evening, and Mars (right, as seen through a good telescope) in the late evening. You can see Jupiter setting in the South-West if you look before 7pm, and you can see Mars rising in the North-East if you look after 7pm. So, for a few minutes at around 7pm, you can see two very bright planets at opposite sides of the sky!
On the 17th, the Moon is just to the right of Jupiter, and on the 18th the Moon has moved just above Jupiter. By the 29th of January, the Moon will have travelled to the other side of the sky and will be next to Mars for the night. Saturn is also visible over night, now rising just before midnight in the south and visible until dawn. Unfortunately, we cannot see either Mercury or Venus this month, as they are both too close to the Sun.
The starry highlight of January is still the constellation of Orion, which I discussed in last months's blog.
