18267767
Description
Flashcards by Kieran Gaydhani, updated more than 1 year ago
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Created by Kieran Gaydhani
almost 5 years ago
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| Question | Answer |
| What shape is the Earth? | oblate spheroid |
| If the diameter of the Earth is 13000km, what is the mean circumference? | 40840.70km |
| Draw the Earth and label the four major internal divisions and describe their features? | |
| What is the latitude of the Earth's North pole? | 90.0000° N |
| What is the latitude of the Earth's equator? | 0° |
| What is the latitude of the Earth's South pole? | 90.0000° S |
| What is the longitude of Greenwich, UK? | 0° E |
| Is Washington DC at longitude 77°E or 77°W? | 77°W |
| Is Delhi at longitude 77°E or 77°W? | 77°E |
| City of Alexandria's latitude is 31.2°N; Syene latitude is 24.1°N, what is the distance between the two cities? | 31.2-24.1 = 7.1 degrees If circumference of earth is 40,840km 40840/360x7.1=805 km |
| Draw Earth on it's axis labelling the following with latitude where relevant: Equator, Tropic of Cancer, Tropic of Capricorn, Arctic Circle, Antarctic Circle, Prime Meridian, North Pole, South Pole | |
| Name 3 atmospheric effects that affect astronomical observations (seeing conditions) and their main sources. | sky glow due to light pollution, sky colour (dust and pollution), twinking - seeing (refraction of the atmosphere) |
| What shape is the moon? | Oblate spheroid |
| The diameters of the Earth and Moon are: 13,000 km and 3500 km respectively. What is the ratio diameter of Earth: diameter of Moon? | 37:10 |
| How do craters appear in naked eye observations of the surface of the moon? | Usually circular, with a rim, sometimes you can discern rays from ejected material from large impact craters like tycho crater, especially during full moon. |
| How do maria appear in naked eye observations of the surface of the moon? | These are darkers areas of the Moon's surface, there is no water in them and few craters, they were formed after the craters |
| How do terrae appear in naked eye observations of the surface of the moon? | These are highland regions formed in the early life of the moon (~4 billions years ago), rock appears light in colour, lots of crators |
| How do mountains appear in naked eye observations of the surface of the moon? | If you look under the low light of a rising sun, a mountain range like the apennines look brighter and ridge like, formed by rims. |
| How do valleys appear in naked eye observations of the surface of the moon? | You need binoculars or telescopes to see Valleys unless you are observing a total eclipse and see the diamond ring. Where ther are valleys in the way more light floods through. |
| How were craters formed on the surface of the moon? | Craters on the Moon are caused by asteroids and meteorites colliding with the lunar surface. |
| How were maria formed on the surface of the moon? | Deep Impacts that caused the crust of the moon to be ejected/vaporised and lava from the mantle released which filled the basin of the crator creating a smooth surface. |
| How were terrae formed on the surface of the moon? | Formed by volcanic activity in the early life of the moon |
| How were mountains formed on the surface of the moon? | Mountain ranges were throuwn up as the rim of a massive crater that led to the formation of the mare. |
| How were valleys formed on the surface of the moon? | Although most are due to impacts some are thought to have arisen due to big temperature changes that have contracted the surface of the crust due to composition of the rocks. |
| Draw the near side of the moon, labelling the following: Sea of tranquillity, Ocean of storms, Sea of Crises, Tycho crater, Copernicus, Kepler, Apening mountain range. | |
| What is the rotation period of the moon? | 27.3, because the rotational period and the revolution period of the moon is the same the smae face of the moon always faces Earth. this is called a synchronous rotation |
| What is the revolution period of the moon? | 27.3, because the rotational period and the revolution period of the moon is the same the smae face of the moon always faces Earth. this is called a synchronous rotation |
| What do we mean by the lunar orbit is synchronous? | for one orbit of the Earth, the Moon spins once and we only see one face of the Moon |
| What causes lunar librations? | Caused by the changes in angle that the Moon’s equator is inclined to the ecliptic, variations in the different positions of the Earth and Moon in their orbits and also where the Moon is viewed from the surface of the Earth. |
| What are lunar librations' effect on the visibility of the lunar disc? | Due to 'wobbles' caused by the changes in angle that the Moons equator in inclined to the ecliptic we can actually see 59% of the Moon’s surface. Features nearer to the edge of the lunar disc(limbs) can be seen to move nearer and further from the edge during a lunar month |
| If you were studying lunar librations, how would you go about doing this? | 1) You would need to observe the Moon over several months. 2) You would make detailed drawings/photos of libration in latitude (the nodding effect, from the UK we would see under the South pole of the moon.) 3. Studying the libration in longitude between perigee and apogee, so detailed drawing on the East and West limbs of the moon. 4. Studying diurnal(daily) libration, during rising and setting times of the moon. 5. if you were able to observe the moon at a very high latitude you could see more over or under the moon |
| Roughly, how many times smaller is the moon in comparison to the Sun? | 400 times |
| Approximately how many times further away is the moon from the sun compared to the moon and the Earth? | 400 times |
| What is the subtending angle between the sun and the moon? | 0.5 degrees (Look up Aristarchus and Eratosthenes discoveries). Using this he could calculate the Earth moon distance using trignometry |
| The diameters of the Sun and Earth are 1.4 x 10^6 km and 1.3 x 10^4 km respectively, what is the ration of the diameters? | 108:1 |
| How many Earth's could you fit between the Earth and the Moon? | 29 |
| How did Eratosthenes and Aristarchus use observations of the sun and moon determine the diameter of the Earth? | |
| How did Eratosthenes and Aristarchus use observations of the sun and moon determine the diameter of the Moon? | He measured the length of time between the moment when the edge of the Moon first entered the umbra and the moment when the Moon was first totally eclipsed. He also measured the duration of the total eclipse. Aristarchus found the two times to be the same and he concluded that the width of the Earth's shadow at the distance where the Moon crosses it must be twice the diameter of the Moon. |
| How did Eratosthenes and Aristarchus use observations of the sun and moon determine the distance to the moon? | His work was based on trigonometry that was understood at his time. He correctly demonstrated that when he saw the Moon was half light and half dark, the Earth-Moon-Sun angle must be a right-angle |
| How did Eratosthenes and Aristarchus use observations of the sun and moon determine the distance to the sun? | His work was based on trigonometry that was understood at his time. He correctly demonstrated that when he saw the Moon was half light and half dark, the Earth-Moon-Sunangle must be a right-angle |
| How did Eratosthenes and Aristarchus use observations of the sun and moon determine the diameter of the Sun? | · Eratosthenes used shadows to determine the circumference (and diameter) of the Earth [3.3a]; · Aristarchus timed the passage of the Moon through the Earth’s umbra during a lunar eclipse to obtain the ratio of the diameters of the Moon and Earth; · the diameter of the Moon was then calculated using this ratio and the Earth’s diameter [3.3b]; · the angular size of the Moon was determined by covering the Moon’s disc with a thumbnail and measuring the width of the thumb and length of the arm; · the distance to the Moon was calculated using ‘trigonometry’ to relate the angular size of the Moon to its diameter and distance [3.3c]; · at the exact time of the Moon’s first quarter (half Moon), Aristarchus measured the angle between the Sun, Earth and Moon to determine the relative distances to the Sun and Moon; · knowing the distance to the Moon, the distance to the Sun could then be calculated [3.3d]; · the angular sizes of the Sun and Moon were known to be equal through observations of total solar eclipses, and so simple ratios enabled the diameter of the Sun to be calculated [3.3e] |
| The mean diameter of the sun is 1.4 x 10^6 km, what is the ratio 'diameter of the sun/diameter of the moon= distance to the sun/distance to the moon'. Therefore what is the distance to the moon from this ratio? | 1.5x10^8/1400000x3500=375,000 km |
| Show diagrams of the Sun, Earth and Moon when there is high tide | |
| Show diagrams of the Sun, Earth and Moon when there is low tide | |
| Show diagrams of the Sun, Earth and Moon when there is spring tide | Same as high tide, lunar and solar gravitational pull align, their combined pull added together creates highs that are very high during new moon and full moon. |
| Show diagrams of the Sun, Earth and Moon when there is neap tide | Same as low tide, during first and third(last) quarter. The gravitational pulls oppose(are at right angles in relation to Earth, and neap or low tides are created instead. |
| Explain precession and how long does it take? | The constellations of the Zodiacal Band appear at different times to the ‘Star Signs’ due to a factor called PRECESSION – caused by the axis of the Earth having a slightly off-centre motion, like the wobble of a spinning top toy. The precession occurs over about a 26,000 year cycle |
| Archaeologists estimate that an ancient stone monument was constructed 580 BCE. Some of the monument's stones were aligned to The Pleiades star cluster in the constellation of Taurus, The Bull. The average rate of precession is 1.4° per century; the stones are no longer aligned with The Pleiades. Estimate the angle by which the stones are now mis-aligned. | 2019+580 = 2599 2599/100=26 26*1.4=36.4 degrees to 1 d.p. |
| The precession rate of planet Tràsköm is 1.1° per century. How many years does it take Tràsköm's axis to precess by 30 arcmin | 0.5/1.1*100=45 |
| Draw diagrams of a partial, total, and annular solar eclipse, include first, second, third and fourth umbral contact | |
| Explain appearances of a partial and a total lunar eclipse, including the terms first, second, third, and fourth umbral contact. | First Contact, edge of moon starts to overlap, 2nd contact the moon covers the disc of the sun, total eclipse begins third contact, moon starts moving away, forth contac the moon stops covering the sun, the eclipse ends. |
| What causes a solar eclipse? | The sun is 400 times further away from us than the moon but is 400 times larger so they appear to be the same size. They last maximum for 7 minutes 30 seconds because of the speed of the Moon orbiting the Earth. Total eclipse only occur along a line on the Earth's surface where the shadow is focussed called the line of totality, observers outside of this see partial eclipses. Solar eclipses only happend during a new moon. At the poles you only see partial eclipses. |
| What is annular eclipse? | When the moon is further away from the Earth (apogee) the smaller moon does not cover the Sun's disc completely, so it is an annular eclipse. The observer see's a ring of fire. |
| What cause lunar eclipses? | The moon moves into the shadow of the Earth. A lunar eclipse can last for over 6 hours from start to finish. It does not occur every full moon as the Moon's orbit around the Earth is inclined at angle of 5 degrees. |
| What causes the moon to appear red? | The Earth's atmosphere refracts some of the light from the Sun all around the planet at one moment in time and this causes light toward the red end of the spectrum to fall on to the moon. The moon never disappears from view as there is some light falling onto it's surface. Any volcanic activity can cause dust in the atmosphere and the Moon then appears more blood red in colour. |
| What is the difference between sidereal and synodic(solar) day? | Sidereal day is when the Earth makes one revolution bringing us back to the same position with the background stars. (23hours 56 minutes) -Earth has spun once on it's axis. The synodic day (Solar day) is 4 minutes longer, it is when the place on earth is back to noon from one day to the next ie in line with the sun(24 hrs) |
| Explain the equation of time and how we determine Apparent Solar time and Mean solar time? | Equation of time = apparent solar time - mean solar time The apparent solar time is the time on sundials The mean solar time is the time on watches The equation of time helps us identify the speed of the sun across the sky |
| How does someone determine Local Mean Time? | Using the equation of time and determining what the apparent solar time is using a sundial or shadow stick |
| Explain when you would use the equation of time | To determine longitude when doing the shadow stick experiment. You would use UTC time, ie correct for BST if required. You would change the minutes to degrees, 1 degree for every 4 minutes and this would indicate your longitude from Greenwich. A positive number is West of Greenwich. |
| How does the equation of time vary over the year? (What is an analemma? How many times a year does AST=MST) | Only during Four days in the year is apparent solar time and mean solar time the same. |
| What causes the annual variation of the equation of time? | Due to the Earth orbiting the sun in an elliptical path, we are closer to the Sun in Winter, when the Earth is travelling faster. The Earth's axis is tilted to the plane of the orbit, therefore the sun reaches different heights above the horizon at noon each day. |
| What are the main errors of doing the shadow stick experiment? | 1) shadow stick too small or too fat 2) Shadow too small due to high summer 3) not enough readings, ie every 2 minutes to show the shortest time to the nearest minute at the U bend. 4) the scale of the graph doesn't help to show clear curve/dip when apparent noon is. 5) Only taking readings for 30mins 6) readings on a windy day clouds affecting readings taken 7) ground not level 8) end of shadow not clear |
| How do you determine local noon using a shadow stick? | 1) Choose a metre rule or a metre long stick an find a suitable flat position 2) Fix shadow stick in a vertical position using set square and firmly positioned in soil 3) Create a clear end to the shadow tip, ie a rod creating a T 4) Take readings every 5 minutes, as the shortest shadow approaches take readings at 2 minute intervals. Put in a table 5) Plot a shadow length curve and work out the shortest shadow time to the nearest minute |
| What is a horizontal sundial? | The style(gnomon) on a horizontal sundial is lined up in a North-south direction, so that the edge is parallel to the axis of the Earth. It can be used anytime of the year. |
| What is a vertical sundial? | It is usually on a wall |
| What is gnomon? | This is the part of the sundial that casts a shadow on to the time dial. Sometime it can be a person (human sundial) |
| What should a gnomon be lined up to? | At the angle of latitude of the site |
| Draw the lunar phase cycle. | It take 29.5 days to complete phases. New moon to first quarter is approx 7 days long, another 7 to full moon, another 7 to last quarter. |
| What is the difference between sidereal and synodic(solar) months for the moon? (Which is longer?) | Sidereal month= the orbit of the moon around the Earth takes 27.3 days. The lunar phase is 29.5 days - this is the synodic month. |
| Explain why sunrise and sunset varies over the year? | Due to tilt of the Earth, if you are at high latitude above the tropic of cancer, during the winter there is less daylight, and in the summer months there is more than 12 hours of daylight. Therefore sunrise is earliest at the summer solstice and sunset is at the latest time, in the North pole, there is no sunset. |
| Explain the astronomical significance of equinoxes and solstices? | During Autumn and Spring equinoxes the Sun crosses the Celestial Equator and the daylight hours are equal to the night hours. During Summer solstice the Sun is at it's greates angular distance above the celestial equator, and the day is the longest. During Winter solstice the sun is at its greatest angular distance below the celestial equator, and the day is the shortest. |
| Explain the variation of the sun's apparent motion during the year, particularly during equinoxes and solstices. Think also about shadows. | Daily variations✰In Britain, shadows point north of the Sun – the Sun is to our south✰Shadows are longest in the early morning and late afternoon, when the Sun is ‘lower’ in the sky✰Shadows are shortest at noon, when the Sun is ‘highest’ in the sky✰Shadows move clockwise, indicating that the Earth is rotating in an anti-clockwise direction |
| What is sidereal time and synodic(solar) time? How are they related? | Sidereal time is the positon related to background stars. Synodic time is position related to the Sun. One is longer than the other due to orbits within orbits. |
| Why do observers experience a difference in local time if they are located at different longitudes even though their time zone is the same? | The locations are either East or West of each other, every degree of distance = 4 minutes, of difference in time. Two locations around 111km will experience a noon 4 minutes apart even though they are in the time zone. Time zones are gnereally 15 degrees of longitude wide. And those at the time zone borders will experience noon closer together but their watches will say a different time. |
| Why do we use time zones? | To help with travel, train, ship and flight times and to communicate together as telecommunication improved. |
| What is the Prime Meridian? What is Universal Time (UT)? | The prime meridian goes through Greenwich. it is where longitude is 0 degrees. Coordinated Universal time(UTC) replaced GMT due to BST. |
| What can we find using the Equation of Time? When is the shadow stick shortest? | Longitude of a location |
| What astronomical methods are there for determining longitude? | Finding polaris in the night sky if you are in the northern hemisphere. Lunar distance method. H-4 clock(1759) that tells time at Greenwich accurately, so that one can compare with the apparent noon of the location. |
| What is the lunar distance method? | The Moon was known to travel about its own width every hour. This distance moved could be judged against the background stars at night, or in daytime by how much nearer or further the Moon was from the Sun. A navigator could compare the time the Moon was near a particular star and compare it with a book of predictions for the reference longitude of Nuremberg. By finding the difference in hours between the two locations and using the fact that the Earth rotated at 15º every hour, the longitude could then be worked out for a ship at sea. But, there were no accurate clocks then, no good star charts, and poor weather would stop observations |
| What is the horological method for the determination of longitude (include Harrison's marine chronometer but knowledge of internal working of chronometers not required) | An accurate clock that lets you know when it is noon at the prime meridian, therefore if compared to apparent noon of location you can determine the longitude. |
| Solar System observation | |
| How can we use pinhole projection to observe the Sun safely? | By not directly looking at the sun. The light goes through a pinhole in a cardboard tube or box and an image of the sun is seen on tracing paper or greaseproof paper |
| What is the annual path called that the observed motion of the Sun follows? | The movement of the sun in the sky is in the ecliptic |
| How do the positions of the planets in the night sky change? | Planets move through a narrow band called the zodiacal band. Direct motion -the planet tracks across the background stars. The slower speed of the outer planets and their orbital inclinations causes the planets to move across the background stars in a west to east motion. Retrograde motion is when a planet appear to loop the loop, it seems to move backward from east to west. At two points on this loop the loop the planet appears to stop and change direction this is called stationary points. |
| What is the zodiacal band? | A narrow band in the sky where the planets can be observed. Planets do not appear to twinkle. |
| Explain retrograde motion of the planets. | That's when they appear to go backwards relative to the stars just because of where we are in the solar system. |
| What does First Point of Aries and First Point of Libra mean? | Spring (vernal) equinox( around march 21): Sun crosses the celestial equator moving from south to north.On the celestial sphere, this is called the First Point of Aries.Autumnal equinox(around Sept 23): Sun crosses the celestial equator moving from north to south.On the celestial sphere, this is called the First Point of Libra. RA is 0hr 0 min and Dec is 0 degrees |
| How do meteors and meteor showers appear and what causes them. Draw why we observe on Earth meteor showers around the same time every year. Explain how we can determine the radiant of a meteor shower. | Meteor showers look like moving stars. They appear to come from the same radiant point. As the earth hurtles through space in it's orbit dust and rocks left from comet trails vaporize in the Earth's atmosphere. Leaving the shutter open on the camera when observing meteors can be used to allow the position of the radiant to be located, as well as allowing the number of meteors in a given time to be counted. Details of each meteor’s magnitude, colour and distance travelled across the sky can also be monitored or stacking photos on top of each other. |
| What is a conjunction(superior and inferior)? | Superior conjunctions are when the planet is on the far side of the Sun from the Earth. Looking across the distance of the majority of an orbit, a planet will look small at times close to conjunction, when the planet is on the far side of the Sun.Inferior conjunctions can only occur with the inferior planets which have their orbit inside the orbit of the Earth, where Mercury or Venus pass on the near side of the Sun. When an inferior planet moves directly across the line of the Sun, a transit, the planet can be seen (but only using specialist equipment) |
| What is opposition? | Opposition is when the Sun, the Earth and an outer planet are in line again, but we look away from the Sun at night to the outer planet. The planet can appear very bright because:-!The distance between the Earth and the outer planet is the smallest it can be, so the outer planet appears quite large!The planet is at its maximum brightness because the sunlight is reflected directly back to Earth :- Magnitudes: Mars -2.8 Jupiter -2.5 Saturn -0.3 Uranus 5.5Opposition can only occur for the outer planets, as the inner planets will always be in the direction looking towards the Sun. Viewing of the outer planets is best at opposition |
| What is elongation? | This is the largest angular distance of Mercury or Venus from the Sun. This is only for the planets that orbit the Sun inside the orbit of the Earth (inferior planets).Greatest elongation is the best time to view these inner planets as they will be seen at their furthest angular distance from the Sun, well away from a line of sight with the Sun. One is as shown in the diagram and the other is when the planet is on the opposite side of the Sun. One gives the opportunity of seeing the planet after the Sun has set (greatest eastern elongation) and the other allows the planet to be seen before dawn (greatest western elongation). |
| What is transit? | The route of a smaller celestial body passing in front of a larger one eg Mercury or Venus in front of the Sun - or a moon in front of its planet eg Io in front of Jupiter. |
| What is occultation? | The route of a celestial body passing behind another one eg when a planet blocks the view of its moon (Io passing behind Jupiter). Other examples are when a planet disappears behind the moon, a star disappears behind a planet, or an asteroid disappears behind the moon. Occultations are common events |
| What is a Celestial observation? | Looking at bodies in space, comets, planets, asteroids, meteors, stars, galaxies and phenomena like aurorae |
| During Naked eye observations describe how the Sun looks | Never look directly at the sun,Circular, bright (too bright to observe directly with the naked eye), yellow coloured object of the daytime. Associated with heat. Tracks across the sky, rising in the east and setting in the west - at its highest point when due south of the observer. |
| During Naked eye observations describe how the Moon looks | Bright white with grey patches. Appears circular when full, but displays gibbous and crescent shapes. Tracks westward in the sky. Can be seen both at night and during daylight hours |
| During Naked eye observations describe how the stars (including double stars, constellations and asterisms) looks | Points of light varying in brightness and colour. Colours red, orange, yellow and blue-white can easily be identified by the naked eye. These slowly track from east to west during the night in a regular arrangement or as a constellation. (The circumpolar stars track anti-clockwise around the pole star) |
| During Naked eye observations describe how the starclusters looks | Groupings of stars from a few hundred to a few hundred thousand |
| During Naked eye observations describe how galaxies and nebulae look | Very small white patches like cotton wool eg the GREAT NEBULA IN ORION |
| During Naked eye observations describe how planets look | Planets near to the Sun can be seen around dawn or dusk. Mercury is only visible as a faint ‘star-like’ object when the Sun is not above the horizon (about 45 minutes before dawn and 45 minutes after sunset). Venus is one of the brightest ‘star-like’ objects that can be seen before and after sunrise in the east or before and after sunset in the west.- Planets further from the Sun than Earth rise in the east and set in the w e s t following a path fairly similar to the motion of a full Moon across the sky. Mars has a red colouration. Jupiter is bright and very easily seen. Saturn is fairly bright but the rings cannot be seen with the naked eye. |
| During Naked eye observations describe how comets look | The head of a comet is seen as a small, fuzzy ball in the sky. If the comet is nearing the Sun, then a long white tail may also be seen (sometimes coloured). |
| During Naked eye observations describe how meteors look | These will flash across the sky, moving out from the radiant. Meteors often occur in groups eg the Leonids and Geminids. These ‘shooting stars’ only last for a few seconds, with occasional fireballs, where the flash is extremely bright. They can range in magnitude from being very faint to being a fireball that could light up the night sky and the ground. |
| During Naked eye observations describe how aurorae look | The most common colour seen is green, with purple and red seen as well. The light is faint and can be stationary or can be seen in moving bands (curtains). The aurorae can cover very large areas of the night sky. |
| During Naked eye observations describe how supernovae and artificial objects, including: artificial satellites look | These move slowly and steadily in their orbit line in a particular direction. Different satellites track in different lines and at different altitudes across the night sky. Geostationary satellites track like stars and could be mistaken for a faint star. However, you can tell that it is a satellite because it may suddenly disappear as it travels into the Earth’s shadow, or suddenly appear as it leaves the Earth’s shadow. Satellites can only be seen if light from the Sun is reflecting off them. They appear to move across the constellations of the night sky. The International Space Station is able to outshine planets like Jupiter, being of magnitude -0.9. Supernovae - depending on distance, it will appear very bright like another Sun if it is Betelgeuse exploding for a few weeks there would be no night |
| During Naked eye observations describe how aircraft look | Aircraft -These have a steady speed, change direction and usually flashing lights can be seen. In the night sky, red and green flashing lights on an aircraft, as well as a constant white light. |
| Draw Cassiopeia including its most prominent stars | |
| Draw Cygnus including its most prominent stars |
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Image:
Cygnus (binary/octet-stream)
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| Draw Orion including its most prominent stars |
Image:
Orion (binary/octet-stream)
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| Draw Plough including its most prominent stars |
Image:
Plough (binary/octet-stream)
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| Draw the Southern Cross including its most prominent stars | |
| Draw the Summer Triangle including its most prominent stars | |
| Draw the Square of Pegasus including its most prominent stars | |
| How do we use asterisms as pointers to locate specific objects in the night sky? | |
| How can you find Arcturus and Polaris from the Plough | Using the handle of the ‘Big Dipper’ or the ‘saucepan’ gives a natural curve from the Plough. This brings you down to the brightest star in the constellation of Boötes, which is the magnitude -0.05 star Arcturus - the brightest star of the northern hemisphere and the fourth brightest star in the night sky |
| How can you find Sirius, Aldebaran and the Pleiades from Orion's Belt | |
| How can you find Fomalhaut and the Andromeda galaxy from Square of Pegasus | |
| Explain why there is a range of constellation, asterism and star names among different cultures? | In olden times, where travelling was only carried out over relatively small distances compared with the present day, different peoples and cultures did not mix and star patterns and names were produced by the individual cultures. In the southern hemisphere, the Inca and Aboriginal peoples saw the ‘Dark Cloud’ constellations as they were observing the skies around the southern cross where dark dust lanes hid areas of stars in their night sky. The names that they gave were related to their animals and language - the same region is a llama in Inca and an emu in Aboriginal cultures |
| How can we use information from star charts, planispheres, computer programs or 'apps' to identify objects in the night sky? | These are very cleverly designed wheels that can show the night sky at any date and time through the year. The important point to note when buying a planisphere is that it is set out for the correct latitude. A the planisphere can be used within 10 ̊ of this latitude. Stellarium, allows all the night sky to be viewed. Whatever is used to plan an observing session, the time that an event takes place, or when you plan to be observing, needs to be known. This, together with the date, can be used to check the night sky at that particular date and time. On charts, the ecliptic is usually displayed – the apparent path of the Sun across the star field. The zodiac may also be mentioned – this is the band, either side of the ecliptic, through which the planets and Moon pass across the star field. There are many different ways that star maps can be presented. A map may show the stars for a month or over a year. The declination could be +30 to -30 |
| Name the causes and effects of light pollution on observations of the night sky. | Where there is greater humidity and clouds, the night sky glows – often with an orange tint caused by the sodium lamps used in street lighting. |
| What is a celestial sphere (you may draw them) | s |
| What are celestial poles (you may draw them) | s |
| What is a celestial equator (you may draw them) | s |
| When and how do we use equatorial coordinate system (right ascension and declination)? | s |
| Why do we use of the horizon coordinate system (altitude and azimuth)? | s |
| How can the observer's latitude be used to link the equatorial and horizon coordinates of an object for the observer's meridian | s |
| How can the observer's meridian define local sidereal time and an object's hour angle? | s |
| How can we use information on equatorial and horizon coordinates to determine the best time to observe a particular celestial object | s |
| How can we use information on equatorial and horizon coordinates to determine the best object(s) to observe at a particular time | s |
| What do cardinal points in relation to astronomical observations, mean? | s |
| What does culmination in relation to astronomical observations, mean? | s |
| What does meridian in relation to astronomical observations, mean? | s |
| What does zenith in relation to astronomical observations, mean? | s |
| What does circumpolarity in relation to astronomical observations, mean? | s |
| What is the diurnal motion of the sky due to the Earth's rotation | s |
| How can we use the star's declination to determine whether the star will be circumpolar from an observer's latitude? | s |
| What is the apparent motion of circumpolar stars, including upper transit (culmination) and lower transit? | s |
| How can we use information about rising and setting times of stars to predict their approximate position in the sky? | s |
| How can we find the latitude of an observer using Polaris? | s |
| What does dark adaptation and averted vision mean? | s |
| Explain why rising and setting affect visibility | s |
| Explain why seeing conditions affect visibility | s |
| Explain why weather conditions affect visibility | s |
| Explain why landscape affects visibility | s |
| How does the Milky Way look from Earth as seen with the naked eye | s |
| What four reasons did ancient civilisations all over the world make detailed observations of solar and lunar cycles? | s |
| Why do current celestial alignment of ancient monuments differ from their original celestial alignment? | s |
| Explain what early geocentric models of the Solar System looked like? | s |
| What are the advantage of the addition of epicycles, as described by Ptolemy? | s |
| What can you say about the scale of the Solar System? Size of Sun, distance to Earth, Neptune, Oort cloud etc | s |
| How far is 2.4 x 1018km in astronomical units (1 AU = 1.5 × 108 km), light year (l.y.) and parsec (pc). | s |
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