February Night Sky


New Moon: 15th. February.

February is an unusual month as it contains a ‘black moon.’ The moon isn’t really black there is no Full moon at all this month, instead there are two full moons in January and March. This phenomenon happens once every twenty years, so enjoy!

Mars lies low in the south east this month moving from Scorpius into Ophiuchus at the start of the month. On the 9th it will be found below the crescent moon and on the 11th. the red planet will be near to the red star Antares. Mars will be slightly feinter than the star but should make for an interesting sight.

Jupiter rises after midnight and shines at a bright -2.0. it lies in the very feint constellation of Libra so will be quite noticeable. On the 7th. the crescent moon passes of the king of the planets.

Saturn rises before dawn but is very low down in Sagittarius. The moon passes to the north of the ringed world on the 11th.

For more of a challenge get your binoculars and see if you can find Uranus. The planet remains in Pisces setting by midnight by month’s end. The crescent moon passes very close by on the 20th.

On This Day:

65 Years Ago – February 21st. 1953: First powered flight of Bell X-1A.

55 Years Ago – February 14th. 1963: Syncom 1 was launched by Thor Delta, from Cape Canaveral. It was the first communications satellite placed in geosynchronous orbit. Unfortunately communications with the satellite was lost shortly after it achieved orbit.

50 Years Ago – February 19th. 1968: Goddard Space Flight Centre launched its 1,000th sounding rocket, an Aerobee 150 carrying X-ray detection instruments it was launched from White Sands Missile Range (WSMR).

45 Years Ago – February 6th. 1973: Marshall Space Flight Centre forms the Large Space Telescope Task Force to plan for and create a preliminary design of a Large Space Telescope (LST). It would be launched by the Space Shuttle in 1990 as the Hubble Space Telescope (HST).

February 15th.: Pioneer 10 crosses the asteroid belt without damage and becomes the world’s farthest travelling spacecraft of the time.

15 Years Ago – February 1st. 2003: After a 16-day mission, STS 107, the Space Shuttle Columbia began its re-entry but broke apart over western Texas at 9:00 a.m. EST when the shuttle was at an altitude of 60 km with a speed of 20,100 km/hr.

The crew did not survive. It was Columbia’s 28th mission. Following an extensive investigation, the Columbia Accident Investigation Board identified the primary reason for the accident: damage caused by foam insulation falling off the External Tank (ET) and striking the leading edge of Columbia’s left wing.

The agency successfully returned the Shuttle to flight on July 26, 2005 with the launch of STS-114, and retired the Shuttle in 2011 with no further accidents.

sts107 patch


Published in: on February 3, 2018 at 16:41  Leave a Comment  

January Night Sky


Night sky at 00h on the 15th. January 2018.

New Moon; 17th. January. Full Moon 2nd. and 31st. January.

There are lots of planets to observe this month, unfortunately you will have to get up early in the morning to see them! There is also a ‘blue moon’ this month; that happens when there are two Full Moons in the same month.

Mercury the closest planet to the Sun rises almost two hours before the Sun at the start of the month (06:39 GMT). The first half of January will be the best time to see this very elusive world as by the month’s end it rises just quarter of an hour before the sun. It will be the brightest object in the feint constellation of Ophiuchus. The moon is north of Mercury on the 15th and Saturn is to Mercury’s upper right on the 13th.

Mars is a also a morning object and like Mercury is also quite low in the sky in Libra. On the 7th the red planet (which shines at magnitude +1.5) will be very close to the much brighter Jupiter. On the 11th the crescent moon will be nearby to the two planets and form a lovely sight.

Jupiter is to be found in the feint constellation of Libra. The king of the planets outshines, at magnitude -1.8, everything nearby.

Saturn is very difficult to see at the start of the month, although by the end of January it may be possible to catch a glimpse of it low in the southwest before sunrise. It lies in the summer constellation of Sagittarius. The moon passes just north of the ringed planet on the 15th.

The first meteor shower of the year peaks this month; the Quadrantids began on the 28th. December, peak on the 3rd. and then come to an end around the 12th. This can be an impressive shower with short sharp meteors. This year the moon will be a problem and will drown out all but the brightest of meteors.

On This Day…

60 Years Ago – January 4th. 1958: Sputnik 1 re-enters Earth’s atmosphere.

50 Years Ago – January 7th. 1968: Surveyor 7 was launched by Atlas Centaur from Cape Canaveral. It Landed on the Moon on the 9TH. of January.

January 22nd.: Apollo 5 was launched by Saturn 1B, from Kennedy Space Centre. It was the first unmanned Earth orbital test of the Apollo spacecraft’s Lunar Module (LM).

45 Years Ago – January 8th. 1973: Luna 21 was launched by Proton K, from Baikonur, USSR. January 16th: Lunokhod 2 drives onto lunar surface, leaving behind the Luna 21 lander.

35 Years Ago – January 26th. 1983: IRAS was launched It was the first of a series of infrared astronomical satellites used to conduct an all-sky survey for objects emitting infrared radiation and to provide a catalogue of infrared sky maps.

15 Years Ago – January 16th 2003: STS-107 (Space Shuttle Columbia) launched at 10:39 a.m. from Kennedy Space Centre (KSC). Crew: Rick D.Husband, William C. McCool, Michael P. Anderson, Kalpana Chawla, David M. Brown, Laurel B. S.Clark, and Ilan Ramon (Israel). As a research mission, the crew was kept busy 24 hours a day performing various science experiments. A landing back at the launch site was planned for February 1st. after a 16-day mission but Columbia and crew were lost during re-entry over East Texas at about 9 a.m. Eastern Time, 16 minutes prior to the scheduled touchdown at KSC. Mission Duration: 15 days, 22 hours, 20 minutes, 22 seconds. Ilan Ramon, an Israeli Air Force pilot, was the first Israeli to fly in space.

January 22nd.: Pioneer 10 spacecraft sends its last signal to Earth, after more than 30 years of operations.

Published in: on December 30, 2017 at 13:07  Leave a Comment  

A Bubbling Star.

We know that eventually the Sun will become a red giant. What then will the Sun look like?

In about 4.5 to 5 billion years the sun will swell and become a red giant star; this happens as the star runs out of hydrogen to fuse for energy and turns to material that’s harder to fuse. This means the balance between gravity and the expansive force caused by this nuclear fusion starts to become unbalanced and the sun will swell. It will then go through a phase of expansion and contraction where it expels its outer layers leaving behind a planetary nebula.

The Sun is very active: images show it to be a swirling, seething place;

solar granulation

The Sun is made from seven different layers;

At the centre is the core, this is where nuclear fusion occurs.

Next there is the radiative zone which “radiates” the energy created in the core by the emission and reabsorption of photons.

Then comes the convection zone; light particles (and all other particles) can take 170,000 years to travel through this layer. The behaviour of photons here is called the “random walk” where the photon collides with other photons: this happens as it is such a dense region.


Next is the photosphere this is the first of the three parts that make up the Sun’s atmosphere: this is where photons are finally emitted and give the sun its brightness. Oddly enough this area is opaque to light, meaning we can’t see trough it. If we could we would be able to view the thermonuclear core directly!

The transfer of energy from the convection zone below appears in the form of granules (see the photo above). As the hotter gas rises up, the cooler gas descends only to be re-heated by the convection layer and the process repeats itself. Sometimes disturbances in the magnetic field will produce sunspots, which occur within the photoshphere.

The chromosphere is next; the temperature ranges from 4400K at the base to 25 000K at its outer edge; no-one knows why the temperature rises so dramatically as it goes away from the surface of the Sun, it’s possible magnetism may be involved but it remains a puzzle.

Finally we have the corona. This outer layer is very dim – a million times dimmer than the photosphere and is the hottest region of the Sun at 10^6 K. Because the Corona extends several million kilometres into space, there is a lot of room for molecules to move. It is this movement that is the source of the solar winds. The high temperature of the Corona can force ions to move as fast as a million kilometres per hour. We can only see the corona during total solar eclipses when the disc of the sun is totally obscured.

It seems that when the Sun does begin to enter its final phases of existence it will still be quite an active place; Astronomers using ESO’s Very Large Telescope have for the first time directly observed granulation patterns on the surface of a star outside the Solar System — the ageing red giant π1 Gruis. It is located 530 light-years from Earth in the constellation of Grus (The Crane), π1 Gruis is a cool red giant. It has about the same mass as our Sun, but is 700 times larger and several thousand times as bright.

The image below from the PIONIER instrument reveals the convective cells that make up the surface of this huge star, which has 700 times the diameter of the Sun. Each cell covers more than a quarter of the star’s diameter and measures about 120 million kilometres across.

The surface of the red giant star π1 Gruis from PIONIER on the

Just one of these granules would extend from the Sun past Venus. The surfaces (photospheres) of many giant stars are obscured by dust, which hinders observations. However, in the case of π1 Gruis, although dust is present it is far from the star so it does not have a significant effect on the new infrared observations.

The Sun’s photosphere, in comparison, contains about two million convective cells, with typical diameters of just 1500 kilometres. The vast size differences in the convective cells of these two stars can be explained in part by their varying surface gravities. π1 Gruis is just 1.5 times the mass of the Sun but much larger, resulting in a much lower surface gravity and just a few, extremely large, granules.

While stars more massive than eight solar masses end their lives in dramatic supernovae explosions, less massive stars like this one – and our Sun – gradually expel their outer layers, resulting in beautiful planetary nebulae. Previous studies of π1 Gruis found a shell of material 0.9 light-years away from the central star, thought to have been ejected around 20 000 years ago. This relatively short period in a star’s life lasts just a few tens of thousands of years – compared to the overall lifetime of several billion – and these observations reveal a new method for probing this fleeting red giant phase.

So it seems there will be a lot to observe on the Sun even as it enters its old age.

PIONIER or the Precision Integrated-Optics Near-infrared Imaging ExpeRiment is an instrument on the Interferometer of the Very Large Telescope. Interferometry is the process of collecting beams of light and combining them together to extract more information and greater resolution from the object being observed. PIONIER can collect up to six beams of light making it incredibly sensitive.

Julien Milli, ESO astronomer at Paranal gives this musical analogy: “the object represents the complete song, and each baseline represents one of the notes that make up the piece. The more baselines we have, the more notes we have, and the more complete our version of the song is.”

PIONIER instrument

Another highlight of PIONIER is its spectral coverage. Adding to the information obtained. For example “…this helps us to characterise the warm dust around a star, providing relevant insights on the formation process,” says Julien Milli.

By using two or more light beams, an interference pattern can be formed with these beams. Because the wavelength of the visible light is very short, small changes in the differences in the optical paths (distance travelled) between the two beams can be detected (as these differences will produce noticeable changes in the interference pattern) meaning more information can be extracted from the light. (This technique is also used in Radio Astronomy.)

How does PIONIER work? It is an interferometer, so once the light reaches the instrument, it is sent across an optical circuit, smaller than a credit card, which brings the light waves from up to four different telescopes together in a very precise way so that they create an interference pattern. An interference pattern consists of fringes, i.e. alternative dark and bright stripes with a given contrast between them, so the final result is not a conventional image.

There’s a lot of engineering goes into Astronomy!

The December Night Sky.




Full Moon; 3rd. December. New Moon: 18th. December.

Venus is low in the dawn sky, it shines at a magnificently bright magnitude of -3.9 but will be lost in the dawn by the 7th. You will need to be quick to see it.

Mars starts the month close to the bright star Spica in Virgo. Mars is slightly feinter than Spica at magnitude +1.7 compared with Spica at +1.0. The red planet is moving eastwards into Libra brightening as it does so and by the months end lies next to the fantastically named star Zubenelgenubi (also known as α Librae.). Libra is a feint constellation and even though this star is the brightest one in Libra (magnitude +2.8) it is much feinter than Mars at magnitude +1.5. Luckily the moon passes to the left of Mars on the 13th. and 14th. so will help you in finding the planet.

Jupiter also lies close to Zubenelgenubi this month (to the star’s left) and shines at a lovely -1.7 (it fades slightly over the month to -1.8.) By the end of the month both Mars and Jupiter will be close by each other lying either side of the star. Use the planets to find the star with binoculars and you won’t be disappointed; α Librae is a double star. It’s companion takes 200,000 years to orbit α Librae. Zubenelgenubi lies almost on the ecliptic which is the path across the sky the planets appear to take. This is why mars and Jupiter are so close to it this month.


On This Day…

100 Years Ago – December 16 1917: Science fiction writer Arthur C. Clarke born. “2001: A Space Odyssey” is one of his best known works. He was also the first person to propose the concept of geostationary satellites.

55 Years Ago – December 14th. 1962: Mariner 2 flew past Venus. It was the first successful planetary flyby.

45 Years Ago – December 7th. 1972: Apollo 17 launched aboard a Saturn V rocket from Cape Canaveral. It Landed on Moon on December 1th.1 in the Taurus-Littrow region. Crew: Eugene A. Cernan, Ronald E. Evans, and Harrison H. Schmitt. It was the last Apollo moon mission.

December 7th.: The “Blue Marble” photograph was taken by the Apollo 17 crew.

15 Years Ago – December 29th. 2002: Shenzhou 4 (meaning Divine Vessel), a Chinese unmanned test satellite was launched from Jiuquan Satellite Launch Centre in north-western China by a Long March 2F rocket. It carried a retrievable crew module with all furnishings, test equipment, and dummy astronauts to assess its viability for a manned launch.

5 Years Ago – December 2012: The Messenger spacecraft discovers water ice in Mercury’s polar regions.


Published in: on December 19, 2017 at 13:03  Leave a Comment  


The earliest writers dreamt of life on the planets in our solar system; the Aborigines have stories dating thousands of years about the Dreamtime and how we came from the stars. The satirist Lucian (120 – c185 AD) claims in “A True Story” to have visited the moon after his ship was caught in a whirlwind which sends them to the Moon: a place inhabited by beings at war with the people of the Sun over the colonisation of the Morning Star, Venus. The title of first science fiction writer is most likely his!

Lucian.                                                       H.G. Wells.

In more recent times we had HG Wells’ ‘War of the Worlds’ (1897) followed a few years later by the astronomer Percival Lowell’s canals on Mars (1906) – where he believed he saw artificial canals, going so far as to draw them – to the idea that Venus might contain dinosaurs we have always been desperate to find life “out there”.

Looking for life beyond Earth is one of the most fascinating, exciting and difficult things to do. Every time we think we might have found a clue a discovery comes along to challenge us.

Modern research looks for ‘bio-markers’; these are chemicals that could only be present as a result of life. Nothing has been found (so far!!) in the solar system so the search has broadened into he universe to the exo-planets, the worlds around distant stars.

How do you find which gasses are present in a world in another solar system? It seems that the size (diameter) of the planet plays a role in whether we can detect atmospheres; a recent report in the Astrophysical Journal (https://arxiv.org/abs/1704.05413) goes into more detail. According to Angelos Tsiaras, the lead author, “More than 3,000 exoplanets have been discovered but, so far, we’ve studied their atmospheres largely on an individual, case-by-case basis.”


Using the Hubble Space telescope researchers looked at the spectral profiles of 30 exoplanets and analysed them for the characteristic fingerprints of gases that might be present. About half had strongly detectable atmospheres. Most of the atmospheres detected show evidence for clouds. The two hottest planets, where temperatures exceed 1,700 degrees Celsius, appear to have clear skies, at least at high altitudes. Results for these two planets indicate that titanium oxide and vanadium oxide are present in addition to the water vapour features found in all 16 of the atmospheres analysed successfully.

It is not only ‘Hot Jupiters’ that have had their atmospheres analysed: in April 2017 it was announced that Gliese 1132b, a super-earth, (that is a planet with a diameter upto 40% greater than the Earth’s) atmosphere had been detected. This is a major step in detecting signs of life in more earth like planets. (https://arxiv.org/abs/1612.02425)

gliese 1132b

How do astronomers detect the atmospheres? Well as a planet passes in front (transits) its host star the light from the star dims slightly; the planet blocks some of the light and the atmosphere absorbs some of the star light. If the composition of the star’s atmosphere is already known, when the planet transits the star, the planet’s atmosphere absorbs some of the starlight and changes what chemicals we can see from the starlight. It Is then possible to work out the composition of the planet’s atmosphere by the effect it had on the starlight.

The chemicals that astronomers look for when seeking life are called ‘bio-markers.’ They include Oxygen and Methane, which tend to be the product of organic processes and a chemical known as Freon-40. This latter was hoped to be a good indicator but, like Lucian’s moon people or Lowell’s canals things are not what they seem.

ALMA and Rosetta Detect Freon-40 in Space

Organohalogen methyl chloride (Freon-40) discovered by ALMA around the infant stars in IRAS 16293-2422

Freon-40 (CH3Cl), also known as methyl chloride. is known as an organohalogen; these are compounds which on Earth are formed by organic processes. Organohalogens consist of halogens (the inert gasses of the periodic table), such as chlorine and fluorine, bonded with carbon and sometimes other elements. On Earth, these compounds are created by some biological processes — in organisms ranging from humans to fungi —  as well as by industrial processes such as the production of dyes and medical drugs.

The idea was if Freon-40 is formed naturally on or earth or through artificial means then its detection in an exo-planet’s atmosphere would be a very good indicator of life, however that hoped has been dashed as Observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) and ESA’s Rosetta mission, have revealed the presence of Freon-40 in gas around both an infant star and a comet. The star lies 400 light years way, the comet is the famous 61/P Churyamov-Gerasimenko; this is the comet that saw the European Rosetta probe orbit it and send the little lander Philae to its surface.

This is the first ever detection of them in interstellar space.

IRAS 16293-2422 in the constellation of Ophiuchus

This chart shows the location of the Rho Ophiuchi star formation region in the constellation of Ophiuchus. The star Rho Ophiuchi, which gives the region its name, is marked with the Greek letter rho (ρ). The position of IRAS 16293-2422, a young binary star with similar mass to the Sun, is marked in red.

This may mean that astronomers have understood things the wrong way round; rather than being a marker for life perhaps it is a necessary constituent of the ‘primordial soup’ from which life arises:

“ALMA’s discovery of organohalogens in the interstellar medium also tells us something about the starting conditions for organic chemistry on planets. Such chemistry is an important step toward the origins of life,” adds Karin Öberg, a co-author on the study.

This isn’t the only chemical that ALMA has detected, other molecules of astrobiological interest found around young stars on scales where planets may be forming have precursors to sugars and amino acids.

The discovery of Freon-40 around Comet 67P strengthens the idea that what we see in the pre-biological chemistry of distant protostars may have been what we would have seen in our own Solar System. It would seem that young solar systems inherit some of their chemical characteristics from their parent star forming cloud and then from cometary impacts.


  ALMA the Atacama Large Millimeter/submillimetrer Array.

It just shows, that when you think you may be onto a clue the Universe has different ideas!

September Night Sky.

sept17 sky

The sky at 00h on the 17th. September.

Full Moon: 6th. September. New Moon: 20th. September.

Autumnal Equinox: 22nd. September.

Mercury reaches greatest Western elongation on the 12th. meaning it rises shortly before the Sun. It is a reasonably bright magnitude -0.4. It will be low down at sunrise so you will need a clear Eastern horizon to see this elusive body. The thin crescent of the waning moon passes nearby on the 19th.

Above Mercury lie two other planets; Venus is a bright -3.9; the moon passes just south on the 18th. The moon also passes very close to the brightest star in Leo, Regulus, the same night. Mars lies between Mercury and Venus and is the faintest of the planets at magnitude 1.8.

Of the giant planets Saturn is the most easily visible; shining between magnitude +0.4 and +0.5 in Ophiuchus. The moon will pass just above it on the 26th and 27th. Saturn remains low in the sky and sets around 9:45 pm.

For more of a challenge why not try to find the distant planets nicknamed the ‘Ice Giants’? Uranus lies in Pisces and is just below naked eye visibility, at magnitude +5.7, but a pair of binoculars should show it as a round object. It is visible most of the night – rising at 7.20 pm by the end of the month.

Neptune will be visible for a week or so after the 6th. It is much feinter at magnitude +7.8 so will be more of a challenge. It is low in the sky in Aquarius. The ‘N’ on the map marks the approximate area in the sky to look next to the star λ Aquarii. The full moon is nearby on the 6th but is so bright it washes out the planet.


On This Day…


165 Years Ago – September 5th. 1857: Konstantin E. Tsiolkovsky, the father of rocketry was born in village of Izhevsk, in the USSR.

55 Years Ago – September 12th. 1962: President John F. Kennedy gives his famous address at Rice University on the nation’s space effort. In this well-known speech, Kennedy stated that we explore space not because it is easy but because it is difficult. This was the beginning of the journey to land men on the moon.

40 Years Ago – September 5th. 1977: Voyager 1was launched from Cape Canaveral on a Titan IIIE-Centaur launch vehicle. This was the beginning of the ‘Grand Tour’ of the planets.

September 29th. 1977: The USSR launched the Salyut-6 space station aboard Proton K rocket from Baikonur.

Tsiolkovsky                                     John F, Kennedy

Published in: on September 14, 2017 at 15:58  Leave a Comment  

Night Sky, August 2017

august sky


The night sky at 23h on the 14th. August.

Full Moon: 7th. August. New Moon: 21st. August.

August is a poor month for planets; Venus lies close to the star Pollux in Gemini and shines at a bright -3.9 in the early morning sky. As the month progresses though Venus begins to move towards the Sun making it harder to observe. The moon passes near Venus over the mornings of the 18th to the 20th.

Jupiter sets now a few hours after sunset and can be found low to the south-west near to the bright star Spica. The moon passes just above Jupiter on the 25th.

Saturn remains in the unremarkable constellation of Ophiuchus this month. It is to be found low in the west and is the brightest object in this part of the sky. The moon passes near to Saturn twice this month, on the 2nd and 30th of the month making a handy marker to the planet.

August sees the Perseid meteor shower, one of the best of the year. It lasts from July 17th until the 24th August and the peak display is usually around the 13th August. Unfortunately the moon is going to get in the way of seeing feinter meteors. To maximise your chances of seeing some meteors try and block street and house lights using walls and trees as shades. Look towards the north – after midnight is best but the moon will be in the way so may make things a bit trickier. The Perseids are made from the debris of comet Swift-Tuttle which was also known as the Great comet of 1862.

This month also sees a total eclipse of the Sun on the 21st. sadly this is only visible from the USA.

One of the most noticeable features in the Summer sky is the ‘Summer Triangle.’ This shape is not a constellation but is made from stars from three different constellations; Deneb in Cygnus, Vega in Lyra and Altair in Aquila. The term was first used by Patrick Moore. It can be found high overhead through out the month and is a handy way of finding three different constellations in one go!


On this Day…


55 years ago, 12th. August 1966 — In the first double flight (occurring at the same time as Vostok 3 with cosmonaut Nicolayev), the Soviet Union launched Vostok 4, with cosmonaut Papel Popovich.

11 years ago, 24th. August 2006 – The International Astronomical Union votes to approve a new definition of “planet” that excludes Pluto, leading to much upset and disagreement in the subsequent years! Pluto was re-classified as a dwarf planet.

5 years ago, 6th. August 2012 – The Mars rover Curiosity lands on the Red Planet as part of NASA’s Mars Science Laboratory mission.

pluto new horizons                                                                                         dwarf planets

Pluto seen by New Horizons.               Artist’s impression of two other dwarf planets.

Published in: on August 19, 2017 at 11:49  Leave a Comment  

The Night Sky May 2017.

nightsky may17

The sky at midnight on the 16th. May 2017. All times GMT.

New moon: 25th Full moon: 10th.

The light evenings of mid-spring present a challenge to Astronomers; fewer dark hours at less convenient times means making the most of the sky when we can.

Look towards the south-west at sunset and you will see the brilliant Jupiter. Over the month it fades slightly from magnitude -2.4 to -2.3 but remains a very noticeable object. It lies in Virgo, Jupiter is above the star Spica which is a first magnitude object, yet compared to Jupiter it does not seem so bright. The moon will pass north of Jupiter on the 8th. and will be a lovely sight. Binoculars or a small telescope will show the four Galilean moons and possibly the cloud belts. Your writer had a look at Jupiter through a three inch telescope a few nights ago and was able to make out the equatorial cloud belts with their distinctive ruddy colour and the moons. SO give it a go!

Rising at 23:30 mid-month and by 22:30 at the end of the month Saturn brightens from magnitude 0.3 to 0.1 over the month. It is to be found in Sagittarius and so will be low in the sky. The moon passes just below Saturn on the 14th. Saturn is a beautiful sight and is always worth a look.

Although there are only two planets (which are fantastic objects to observe) there are other things to look at. If you find Leo, the star to the left is called Denebola, to the left of there lies the Virgo cluster. This is a rich area of galaxies which form part of the ‘Local Cluster’ of galaxies to which our Milky Way belongs. There are over 2000 galaxies in the Virgo cluster, many of which can be seen by amateurs – they will appear as fuzzy blobs, but don’t let hat put you off. The light you see form them has be travelling to your eye for millions of years!

On this Day…

90 Years Ago – May 20th.-21st. 1927: Charles A. Lindbergh made the first solo nonstop flight across the Atlantic Ocean. Lucky Lindy’s single-seat, single engine aeroplane was called the Spirit of St. Louis. It began the flight from Roosevelt Field in New York and landed at Le Bourget Air Field just outside Paris.

45 Years Ago – May 24th. 1972: U.S. President Richard M. Nixon and USSR Premier Aleksey N. Kosygin signed an agreement for cooperation in the exploration of outer space for peaceful purposes which included the docking in space of US/USSR spacecraft in 1975. It was signed in Moscow.

5 Years Ago – May 22nd. 2012: Dragon C2/C3 was launched from Cape Canaveral by a Falcon 9 rocket. The spacecraft was the first fully functional Dragon spacecraft on the Commercial Orbital Transportation Services (COTS) C2+ Demonstration Mission for NASA. It successfully docked with the ISS and was later recovered.

Published in: on May 2, 2017 at 11:32  Leave a Comment  
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B-Ring It On!



What do you think this picture might be? Could it be a microscope’s view of a hair? Could it be the pages of a really big book? They’re not bad guesses but they’re not correct.

This image focuses on a region in Saturn’s B ring, which is seen in twice as much detail as ever before, revealing a wealth of rich structure. It shows the incredible detail at which the international Cassini spacecraft is observing Saturn’s rings of icy debris as part of its dedicated close ‘ring grazing’ orbits. The spacecraft was at a distance of about 51 000 km from the rings

Saturn’s rings are composed mainly of water ice and range from tiny dust-size specks to boulders tens of metres across. Some of the patterns seen in Cassini’s close images of the rings are generated by gravitational interactions with Saturn’s many moons, these are known as shepherd moons which by their gravity help to keep the rings in shape by ‘kicking’ material into the rings or out into space. However many details remain unexplained.


A Cassini image looking across Saturn’s rings showing where the B-ring lies.

The spacecraft’s ring-grazing orbits began last November, and will continue until late April, when the mission enters its ‘grand finale’ phase. During 22 final orbits Cassini will repeatedly dive through the gap between the rings and Saturn before plunging into the planet’s atmosphere in mid-September to conclude its incredible 13-year odyssey around the Saturn system.

If you want to see Saturn and its rings this is a good time to do it; Saturn rises about 2:15 in the morning in mid-March and an hour earlier by mid-April and lies in the constellation Sagittarius. That means for us that it is quite low in the sky. It gets to its highest point in the sky a little before sunrise, so you have a good chance of seeing it. (Sagittarius is a lovely constellation full of objects as when you look at it you are looking in the direction of the centre of our galaxy the Milky Way.)

You will need to look towards the East and South to see it but it will be the brightest object in that part of the sky.

To help you find it the moon will be either side of Saturn on the 16th and 17th of April.

Binoculars will show that it has a funny shape, almost like a rugby ball, and a small telescope will begin to show the rings. The rings are currently tilted towards us and will make for a lovely sight.

The Cassini-Huygens mission is a joint venture between NASA, ESA (the European Space Agency) and the Italian space agency ASI. It was launched from Cape Canaveral on the 15th. October 1997 aboard a Titan IV-B which is the NASA’s largest and most powerful rocket.

Published in: on March 26, 2017 at 12:14  Leave a Comment  
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Oh My!

The solar system is full of amazing sights; from aurora on Earth, to giant solar flares, to the great red spot there are countless objects to fascinate us. every now and then comes along something you just don’t expect. Often these are from objects you just wouldn’t imagine to be interesting (which just proves the old adage; ‘never judge a book by its cover.’)

The Cassini mission to Saturn (launched on October 15th. 1997 and arrived seven years later) is starting to wind down (sadly) and will soon be sent on a course that will see it fly through Saturn’s rings and eventually into the planet’s atmosphere to be destroyed. Despite that it is still providing us with surprises; the most recent being its images of the little shepherd moon Pan.

759Raw image of Pan. NASA. The grey lines either side of Pan are rings of Saturn!!

Looking through a telescope at Saturn from Earth the rings look quite simple; there


appear to be two sets separated by  black gaps or ‘divisions’. the Encke division is very difficult to see and cuts around the A ring. The second gap is the Cassini division and is much easier to see, lying between the A and B ring. The image below also shows the C ring or crepe ring which is very difficult to see in amateur telescopes and is only hinted at in the above Nordic telescope image.

post-6974-0-24780700-1405571735Stargazer’s lounge image. (Just for clarity and because you can never have too many pictures of Saturn!)

This begs the question: how are the rings able to stay so neat? could it be gravity and that he material that makes up the rings be in just the right place that they don’t change?

Pioneer 11  became the first spacecraft to visit Saturn. It was launched from Cape Canaveral  on the 5th. April 1973. Pioneer 11’s path through Saturn’s outer rings took it within 21,000 km of the planet, where it discovered two new moons (almost colliding with one of them in September 1979) and a new “F” ring. Saturn from Pioneer looked very similar to Saturn through a telescope.

739508main_739460main_AC79-9107_3-full_full Pioneer 11 image of Saturn.

It wasn’t until the Voyager spacecraft flew past Saturn ( Voyager 1 in November 1980 and Voyager 2 in August 1981) that we began to realise what a complicated and far more extensive system the rings formed.

8bg                       Saturn’s rings with “spoke” features in B-ring. Aug. 22, 1981. Distance 2.5 million miles.

The spokes created much excitement and discussion and were endlessly replayed in a video sequence on TV…and to be honest I did and still could watch them happily for hours.

10bg The F-ring (discovered by Pioneer 11.) Two braided but separate orbit rings. Nov. 12, 1980. Range 750,000 km.

A clue to the structure of the rings was found by Voyager 1 when  it discovered three new moons, Prometheus, Pandora, and Atlas. Prometheus and Pandora are shepherding moons of the F-rings, and Atlas is a shepherd of the A-rings. After a lot of analysis and some careful thinking it was realised that these moons are able to control the movement (or shepherd) of material making up the rings by either pushing the material into place in the rings or ejecting stray material from the system all together. All this is done by the gravitational force of the much larger satellites on the smaller material that makes the rings. Pan creates stripes called “wakes” ( which are places where ring material has collected in an orderly manner) in the ring material on either side of it. Since ring particles closer to Saturn than Pan move faster in their orbits, these particles pass the moon and receive a gravitational “kick”. This kick causes waves to develop in the gap and also throughout the ring, extending hundreds of miles into the rings. These waves intersect downstream to create the wakes.

Pan has a similar shape to Atlas and that unusual shape may be the result of fine material from the rings aggregating on the surface of the moon.

A little more about Pan before we go: it was discovered on the 16th. July 1990 by Mark Showalter who was working on Voyager data. It is approximately 35 kilometres across and 23 km wide. It lies within the Encke Gap in Saturn’s A Ring. It orbits Saturn every 13.8 hours, at a distance of 134,000 kilometres and is responsible for keeping the 325 kilometre wide Encke Gap open.

There are many fascinating worlds around Saturn – have a look for Daphnis another shepherd moon as well as the ones mentioned above.

To give you an idea of the complexity of the ring system here is another image from Cassini: