see www.hants.gov.uk for what is on in Hampshire
Pictures of Chilbolton taken by Doreen Rowles, Alan Crisp and others at various other times of the year
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| The sun and the planets more or less to scale | |
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http://www.esa.int/esaCP/index.html is the web site for the European Space Agency, worth a look.
The great event of early July was the space probe hitting Temper 1. The probe the size of a washing machine was parked inspace and the mother ship moved to film the impact; and here it is.
http://www.nasa.gov/mission_pages/deepimpact/multimedia/index.html
ALTHOUGH the Sun has now turned southwards, we must wait for another few weeks before our summer nights become noticeably darker and we can reacquaint ourselves with the fainter stars. As it is, the bright twilight hinders observations of the dim Comet Tempel 1, which was the target for NASA's Deep Impact mission on Monday, 4 July.
That, of course, is Independence Day in the United States, and there is some speculation about the firework display we can expect when Deep Impact's 272 kg impactor module slams into the comet's nucleus at 10 km per second.
Tempel 1's potato-shaped nucleus is thought to measure some 14 by 5 km, and the kinetic energy of the impact should blast a crater, eject a flurry of ice and dust into the comet's coma and tail and expose fresh ice to the heat of the Sun. Meantime, the main Deep Impact craft will stand off at some 500 km to study the impact and its aftermath, while telescopes back on (and in orbit above) the Earth will also monitor events. Sadly for us, the event occurs at 06:52 BST next Monday, when it is daylight and the comet lies well below our horizon.
Even assuming the collision occurs as planned, it is impossible to be sure of its effect on the comet or of the size of the resulting crater. If the nucleus's crust if much more rigid than expected, the strike may cause only a minor dent, with little or no change in the comet's overall appearance. At the other extreme, there is a slim chance that the impact will shatter the nucleus into two or more pieces.
The expectation, though, is that the crater will lie somewhere between the size of a house and a football stadium, and that the ice and dust thrown out, and the (perhaps) pristine ice exposed, may result in the comet brightening significantly from its current status as a 10th magnitude telescopic smudge. Indeed, it might become an easy binocular object for those with darker skies than we enjoy at present. How long the improvement will persist is anyone's guess, but we can hope that something of the aftermath will be evident over the following evenings, when the comet stands low in our south-western evening sky.
In fact, it is the giant planet Jupiter that is unmistakably low in the south-west at nightfall, sinking to set in the west just before star map times. This month it fades a little from magnitude -2.0 to -1.8, while a telescope shows its disk to be 35 arcseconds wide when it stands near the Moon on the 13th. Jupiter still lies close to the Star Porrima in Virgo, though it edges 3° eastwards (to the left) taking it close to Virgo's brightest star, Spica. Comet Tempel 1 lies 3.3° above Spica on the evening of the 1st, moving to 3.7° above-left of Spica by the 4th as it tracks to the left at about 0.6° per day. The comet reaches perihelion, its closest point to the Sun in its 5.5 years orbit, on the 5th and lies 225 million km from the Sun, and 134 million km from the Earth, at the time of the impact on 4th.
Sunrise/sunset times for the UK change from 04:32/22:01 BST on the 1st to 05:15/21:22 on the 31st. Nautical twilight lingers throughout every night until that of the 12th/13th and for two hours at dusk and dawn on the 31st. New moon on the 6th is followed by first quarter on the 14th, full moon on the 21st and last quarter on the 28th.
Venus is brilliant at magnitude -3.9 but is increasingly difficult to spot in our evening twilight, even though it is drawing further away from the Sun. The reason is that Venus is tracking southwards in relation to the Sun, with the result that it stands lower in the west-north-west at sunset and sets earlier each evening, from 82 minutes after the Sun on the 1st to only 60 minutes on the 31st. Moments after sunset on the 1st, Venus stands 9° high and 22° left of the sunset position.
If the sky is really clear, and if you have binoculars, you may glimpse the much fainter Mercury only 0.9° below-left of Venus as the twilight begins to fade. Mercury is then magnitude 0.1, dimming to 0.5 by the 8th when it lies 2° below Venus, with the extremely slender Moon a similar distance above Venus. Mercury stands at its furthest east of the Sun, 26°, on the 9th, while Saturn, no longer on show in the evening, reaches conjunction on the Sun's far side on the 23rd.
Our July star maps show the welcome return of Mars, which climbs from very low in the east at our map times to stand well up in the south-east before dawn. The Red Planet is moving eastwards in Pisces, below the Square of Pegasus, and brightens from magnitude -0.1 to -0.5 so that it outshines every star in our morning sky. Look for it 6° below and left of the (precisely) last quarter Moon on the morning of the 28th, when a telescope shows it as a small rust-coloured gibbous disk, 11 arcseconds in diameter, 84 per cent sunlit and 127 million km distant.
The Summer Triangle, formed by the bright stars Vega, Deneb and Altair, stands very high in the south at our star map times. Low in the south is Sagittarius and the starry regions towards the centre of our Galaxy. The Milky Way arcs upwards from Sagittarius, through Aquila and onwards, close to Deneb in Cygnus, before tumbling downward in the north-east through Cepheus and Cassiopeia.
Worth checking is the variable star Chi Cygni, which lies 2.5° south-west (below-right) of Eta Cygni in the neck of Cygnus (see south map). Akin to Mira in Cetus, Chi is a long period variable, a red giant that pulsates in a cycle of some 406 days. At its faintest, it can dip below the 14th magnitude, making it a difficult telescopic target. At maximum brightness, though, it has been known to outshine the magnitude 3.9 of Eta though it is usually closer to the 5th magnitude. If it keeps to schedule, the next maximum is due in the coming week or two, when its reddish hue should be striking in our twilight sky if we spy it through binoculars.
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JUNE
The highlight of the month, indeed the whole year, has got to be the transit of Venus, an event which last occurred in 1882 and which will not happen again until 2012. On the 8th of June Venus will transit in front of the face of the Sun.
In late June the skys have been wonderful with long evenings. This has made it difficult to spot our friends in the skys but moments after sunset from the 26th Venus an be spotted 10 degrees higher than the setting sun nd 20 degrees to the left. It sinks to set about 90 minutes later at which time you should see Murcury about what looks like an inch or so near it. Jupiter is fairly evident in Virgo in the South West at nightfall. It sets in the west at 1.20 am just as Mars rises in the East. They all all out there to see withthe naked eye.
A great site to visit is http://ares.esa.int/index.html which is the European Space Agencies site with links to NASA etc
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| Eta Aquarids | |
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The Night Sky in May The planets of our solar system dominate the evening sky early in May. Venus is far and away the brightest object in the night sky. It lies low in the northwestern sky at sunset. Almost on the horizon (and difficult to see on all but the clearest nights with an uninterrupted view of the horizon) is Mercury. In ascending order above Venus lie Mars (very faint), Saturn and Jupiter. On the 5th of the month Mars and Venus will form an alignment, appearing to us as a single bright point. If you have a clear view of the southwestern horizon then you might look out for the constellation Hydra which stretches across much of the sky between southeast and west. The moon reaches its last quarter on the 4th May. The next new moon is at 11;45 on the 12th with the full moon on the 26th at 12;51. The Eta Aquarids meteor shower should be visible on the morning of the 5th May. Not one of the most spectacular of meteor showers, the radiant (the point from which meteors appear to originate) never reaches very high in the night sky before morning twilight. So try facing towards the east and look high above your head. Expect to see no more than 10 meteors per hour. The International Space Station (see the photos of the Station a little further down this page)puts in an appearance later this month, clearly visible for the first time on the morning of the 23rd. Meanwhile the next Space Shuttle mission is scheduled for the 30th May. The Endeavour and its seven crew will undertake a 12 day mission to rotate the crew aboard the ISS and deliver a multipurpose logistics module. At about 7am BST on the 4th May a Delta II rocket is scheduled to launch from Vandenberg Air Force Base. It will be carrying a NASA Earth Science satellite ‘Aqua’ which will be collecting data on the Earth’s water cycle. |
The Envisat which already gathers similar data continues to orbit above our skies. Although not as bright as the ISS it is easy to find in the night sky as it can take about nine minutes to pass from south to north. From the Common this should be easy to see. Let me know if you can.
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Image by NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA)
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| JUPITER | |
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Night Sky in April
Jupiter
Well, March gave us wonderful night skies to see just how insignificant we all are in the great scheme of things. Machholz is now far away heading for deep space but Jupiter is the star of April. On the 2nd Jupiter comes in to opposition - when Jupiter is exactly opposite the Sun, so the Sun, Earth and Jupiter are in line. This, of course, means that Jupiter is closest to us and will be visible all night passing due south close to midnight. Jupiter will thus be at its brightest and biggest. It is visible all night in Virgo, that is in the south. In the moonless first two weeks of the month there is much to see of its stormy atmosphere. With binoculars it should be possible to see its four moons, three of which are larger than ours. This may be the case but I could not make them out, I must need better equipment. This year, just 11 days before opposition, Jupiter was at aphelion - when it is furthest from the Sun in its slightly elliptical orbit. This means that this closest approach is essentially the least close it ever is and Jupiter, at 44.2 arc seconds across, is 6 arc seconds smaller in angular diameter than when it is at its closest to us (when Jupiter is near perihelion at the time of opposition). It shines at magnitude -2.5 and a small telescope will show the equatorial bands and the great red spot on the surface as well as the 4 Galilean Moons weaving their way around it.
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Saturn
This is a wonderful image of Saturn taken by the Cassini spacecraft as it passed through the plane of Saturn's ring system. The vantage point shows that the rings are only tens of metres thick! Two satellites of Saturn are also in view. Dione, 695 miles across, is to the left with Enceladus, 314 miles across, to the right. Two bright storms are seen within the belt below the rings whilst the ring's shadows fall on the surface above. The thin arc nearest the pole is the shadow cast by the F ring. Then follows the A ring with Encke's Division visible within it. There is then the broad gap of Cassini's Division before the B (or bright) ring. It appears brightest to us as the density of particles within it is high and hence the shadow it casts is deeper - as seen in the picture. Finally there is the C ring in which the density of particles is less so it appears less bright when viewed form Earth. To see many of the Cassini images visit the website of the Cassini Imaging Central Laboratory for Operations (CICLOPS) by putting CICLOPS into Google.
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Space Station
The Space Station may be old and full of junk, old experiments,like my garage but it is still there and still visable from Chilbolton if you know where to look. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked gives details for several cities in the UK. ( Across the world too for foreign visitors to this web page.)
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| Just to help you find the Comet | |
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The Night Sky in March
Comet Machholz which I mentioned last month should still be visable through binoculars for a few nights around the 9th March. It is close to the North Star. Comet Machholz will be at its closest to Earth Jan. 5-6, 2005, when it will be 32 million miles away.People with dark rural skies and a good map should be able to find it on Moon-free nights now especially around where we live. Backyard astronomers have been watching Machholz for months through telescopes. It was spotted by naked-eye observers for the first time in the Southern Hemisphere by Donald Machholz, who first found the frozen chunk of rock and ice in August last year.
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| A photo from the Hubble telescope.Included as I like it. | |
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So what else is happening. Well as it is Spring the Sun moves rapidly northwards during March, and crosses the equator on March 20. On this date the Sun will rise due East, and set due West. By some definitions, this is the beginning of Spring in the northern hemisphere. The other inner planet, Mercury, makes its best evening appearance for those of us in the northern hemisphere.When Mercury reaches greatest eastern elongation in March, as it does this year (on March 12) then the planet will be as high above the horizon as possible, and remain visible for at least an hour before setting. Its brightness will be similar to that of Saturn or stars such as Vega or Capella. Look for it in the west or west-north-west, near the horizon, using binoculars, at first. However, once found it can be easily seen with the unaided eye. It may show a slight pink or peach hue, but will not reveal any detail except to the largest of telescopes. On the evening of March 11, a thin crescent Moon only 3.5° away will help. More detail will be forthcoming about Mercury when the Messenger probe, launched last August, goes into orbit around this moderate sized planet in March 2011.
The planet Saturn is well above the horizon as the sky darkens in the evening. It is located south of Castor and Pollux, the primary stars of the constellation of Gemini, the twins. With its rings still fairly wide open, Saturn is perceptibly brighter than both of these first magnitude stars. Saturn ceases to retrograde, bringing it to a stationary point around mid-March near the star delta Geminorum. Thereafter, it commences its more normal eastward movement. It was in this region the planet Pluto was discovered exactly 75 years ago, by Clyde Tombaugh. The confirmatory photographs were taken on 1930 March 2 and March 5. Saturn also has its anniversary to celebrate, since it is 350 years since the discovery of Titan, in 1655 by Christiaan Huygens. What would he have thought about a probe, named after him, landing successfully on Titan and sending back a multitude of information about the small dot that he spotted in his telescope? (see last months photos) The Moon passes about 5° north of Saturn on the evening of March 19. The other giant planet, Jupiter becomes more available for evening viewing. Rising soon after 9 p.m. at the beginning of March, it is visible all night by the end of the month, as it approaches opposition early in April. The Moon passes Jupiter on March 26. Jupiter is found in the constellation of Virgo, as is the minor planet.
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| The Huygen Probe seen against Titan | |
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The Night Sky in February
Even from the clear skys over Chilbolton it would not have been possioble to have seen the landing of the Huygens space probe.The probe driftred through the atmosphere of Titan for just over two and a half hours, landed and beamed back results for an hour or so before running out of power. Early result show that there is liquid methane on surface of Titan as opposed to water on Earth. That rocks on Titan constitute dirty ice as opposed to silicate rocks found on Earth
Surface temperature confirmed at 94 K
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| The new moon in January against Scorpio | |
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Whilst there is little of special interest to report this month, the night sky in February is still worth studying.
Many of the major constellations are high in the sky and it can be well worthwhile braving the low temperatures if the skies remain clear.
The next Moon rises on the 8th of the month and the next full moon is on the 24th February. The first planet visible in the evening sky is Saturn. At the start of the month this appears in Taurus at sunset. It is followed by Jupiter which is much brighter
Venus remains very bright in the morning sky with the much fainter Mars lying nearby.
There are no Space Shuttle missions planned for this month but the International Space Station should be visible for the first two weeks of the month.
There are no significant meteor showers during the month of February.
The hours of darkness begin to decrease significantly during February. As this is also one of our drier winter months there should, statistically at least, be some fine nights to enjoy the night sky.
If you look fairly high up in the southwestern sky in the early evening you can see clearly the planet Mars. Of course, what you cannot see is all the action taking place on the planet's surface.
While the European Beagle probably lies in a million pieces scattered over the planet's surface, NASA's twin Rovers, Opportunity and Spirit are still going strong. Earlier problems with Spirit have now been overcome with a system 'reboot', and both craft are engaged in some serious geological works.
Another planet which is clearly visible in the evening sky, from about 9pm onwards, is Jupiter. There is plenty to see on Jupiter although this concerns not man-made craft, but a natural phenomenon - the Red Spot. This vortex of swirling gases has been continuously observed since 1878 but it has shrunk in size since it reached its peak in the late 19th century.
Venus is becoming increasingly prominent in the evening sky and is far brighter than any other planet. It sets at about the same time Jupiter rises.
Saturn is high in the southeastern sky during the evening. Even binoculars can reveal details of the planet's rings, although you will need to mount them on a tripod.
Watch out for the comet C/2002 in the southeastern corner of the Square of Pegasus. It should be visible with good binoculars. There are no significant meteor showers this month, but the sighting of a rogue meteor is possible on any clear night.
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The Night sky in January
The most important man made event which will take place in the solar system this month will be the decent of Europe's probe Huygens into the murky atmosphere of Saturn's moon Titan. Titan is the only moon in the solar system which has its own atmosphere. It is thought that this atmosphere resembles that of the Earth's 3.8 million years ago, before the coming of life. It is hoped that we may learn a little more about how life or Earth started.
From places of low light pollution such as West Down and the Common the comet Machholz will be visible by the naked eye or at least with binoculars on the night of the 5th and 6th. It should be spotted in the South Eastern sky moving in a Westerly direction. It will be close to the Pleiades star cluster which in the winter comprises seven bright stars easily visible in the night sky, they are known as the Seven Sisters.
Of the planets, Saturn is visible in the centre of the sky to the south close to two other bright stars called Pollux and Castor but Saturn outshines them both. Jupiter will rise just after midnight and Mars will be visible around 6.00am low in the South East. Venus is also to be found in the South East a brilliant object in the early morning. So if you look around when on the way to work the sky will be a wonderful sight.
The Moon is full on the 25th and new on the 10th so it will be wonderful time of 'photos for the stars and the Moon especially if there is a frost.
As this is the first time this column has been written the map of the stars to help identify where things are, is not as clear as it might be, but we are working to improve the image.
Website by Tony Blighe at 123Live (updatable websites)
Email: info@chilbolton.com Website: www.123live.co.uk