t1:Haze,Fog Cloud so thick that the planet appears dim in a telescope but no detail can be seen.Turbulence is seen at its most prominent on a sharply focused star.The star will appear to twinkle,the star will also move around in the the centre of the telescope.The turbulence is not only effected by the climate and weather at the observing site but the area where it is placed in the observing site.If the telescope is placed over areas where heat may be rising then,this will cause turbulence.
The Planets
The
Planets. |
Planets
Apparent
Diameter. |
Magnification. |
| Mercury. |
4.8°-13.3°. |
280x at Elongation(6.5°). |
| Venus. |
10.0°-64.0°. |
70x at Elongation(25.0°). |
| Mars. |
4.0°-25.0°. |
70x at Opposition. |
| Jupiter. |
31°-48.0°. |
40x at Opposition. |
| Saturn. |
15.0°-21.0°. |
100x at Opposition. |
| Uranus. |
3.0°-4.0°. |
500x at Opposition. |
| Neptune. |
2.5°. |
750x at Opposition |
This Chart shows at what magnifications
the planets would appear the same sizes as a full Moon in the sky.
Mercury:
Mercury is 36 million miles from the Sun.It is similar to the Moon,it is heavily cratered.Mercury also has mountain ranges like the Moon,these were caused by seismic movement caused by large impacts.Mercury has been visited by a probe,called Mariner 10 which visited the planet in 1973,it was put into orbit around the Sun.It made three passes of the planet before its cameras failed in 1974.Mariner 10 discovered that the planet appears to have been shrunk after being formed,this caused rings called Scraps.These are unique to Mercury.The Scraps are 500 to 1000 meters high,and hundreds of miles long.They are caused by the movement of the crust with the heating and cooling of the planet interior . The planets crust must have been disrupted when Mercury's rotation was slowed to today's rate,this was caused by the Suns gravitational rate .
Its largest angular distance from the Sun is 28º at maximum elongation.It is best seen in twilight . No detail as such can be seen in a fairly large telescope some shading can be seen . Mercury has phases like the Moon,these happen over a 116 day period.
Day0:Superior Conjunction,"Full Mercury".
Day 12:Mercury appears in the evening sky.
Day 36:Greatest eastern elongation,"last quarter".
Day 47:Retrogression of Mercury begins.
Day 53:Mercury disappears the evening sky.
Day 58:Inferior conjunction,"new Mercury."
Day 63:Mercury appears in the morning sky.
Day 69:Retrogression ends.
Day 80:Greatest western elongation,"first quarter."
Day 104:Mercury disappears from the morning sky.
Day 116:Next superior conjunction,"full Mercury"..Northern observer mid latitude will have their best opportunity to observe the planet in the spring sky.In the evening sky and in the autumn during the morning.The observer nearer the equator will have better observing configurations,due to the steeper angle of the ecliptic to the horizon,or in the southern Hemisphere,as Mercury,at times of maximum elongation,is farther South than the Sun.Transits:This is where the disc of Mercury passes in front of the face of the Sun.This will cause a black disc to move across the face of the Sun and should be seen using the projection method.
Mercury is 36 million miles from the Sun.It is similar to the Moon, and is heavily cratered.Mercury also has mountain ranges,like the Moon these were caused by seismic waves caused by large impacts.This planet is closest to the Sun and is visible as a small star and is always near the horizon.
General Information:
Mercury has a sidereal period of 88 Earth days and a rotational period of 58.6 Earth days.The surface temperature -180° C in the shade to +430° C in the Sun light and has a maximum distance from Sun 57.9 million km's/36 million miles and its equatorial Diameter 4,879km/3,030 miles.
Mercury Atmosphere:
Surface Pressure: ~10-15 bar (0.001 picobar)
Average temperature: 440 K (590-725 K, sunward side)
Atmospheric composition:
42% Oxygen (O2), 29% Sodium (Na),
22% Hydrogen (H2), 6% Helium (He), 0.5% Potassium (K),
possible trace amounts of Argon (Ar), Carbon Dioxide (CO2),
Water (H2O), Nitrogen (N2), Xenon (Xe), Krypton (Kr), Neon (Ne)
(Compositional values not well constrained, values from "Mercury" Vilas,
Chapman, and Matthews, eds., University of Arizona Press, 1988)
Venus:
The second closest to the Sun.Venuses cloud are made of Carbon Dioxide and Sulphuric Acid which causes a green house effect.There is another problem its pressure under the cloud is 90 times that of the Earth.The surface temperature is 465°C.So if you were to land on Venus you would be
POISONED:By the deadly mixture of gases.
SUFFOCATE:You would suffocate because you would be unable to breath the air.
MELTED:By the extreme temperature.
CORRODED:By the acid.
CRUSHED:By the pressure on the surface.
It was once thought be like Earth but it is a dead planet.The planet has been visited by many American space probes.The American probes took pictures of the planet and saw only the clouds,these probes were the Mariner and Pioneer class probes.An American probe called Megellan used radar to see though the cloud to map the surface of the planet. The probe arrived on the 15th of August 1990.The Megellan mission was a total success,as now we know how the surface of Venus appears.A total map of the surface has been made by Megellan,this was done using radar by bouncing it of the surface showed valley's,mountains and other surface detail as well.Russia sent probes which landed on Venus,they sent back pictures of the surface of the planet but only a short range was seen.All it saw was a rocky surface.The Russian probes called Venera lasted at most an hour because of the pressure and heat.
Venus is more conspicuous than Mercury as gets higher than Mercury,at its largest angular distance from the Sun is 47° . Because of this fact it can be seen for a few hours before Sunset and after Sunrise.Venus again has phases like the Moon.Counting from superior conjunction,the visibility pattern is as follows.
Day 0:Superior Conjunction,"Full Venus".
Day 35:Venus appears in the evening sky.
Day 221:Greatest eastern elongation,"last quarter".
Day 271:Retrogression of Venus begins.
Day 286:Venus disappears from the evening sky.
Day 292:Inferior conjunction,"new Venus".
Day 298:Venus appears in the morning sky.
Day 313:Retrogression ends.
Day 362:Greatest western elongation,"first quarter."
Day 549:Venus disappears from the morning sky.
Day 584:Next superior conjunction,"full Venus". Venus can be observed for a period of about 7 months at each elongation. The planet reaches its brilliancy 35 days after eastern elongation,and 35 day's before western elongation . As for surface detail none can be seen as Venus is covered with clouds,however no real detail can be seen in the planets clouds,but some reports differences in brightening or darkening in shading.Again Venus does move across the face of the Sun causing a transit.)
General Information:
Venus sidereal Period is 224.7 Earth days and has a Rotational Period of 243.2 Earth Days Mean distance from the Sun 108 million km/67 million miles,The Equatorial diameter is 12,100Km/7,520 miles.
Venus Atmosphere:
Surface Pressure: 92 bars
Surface Density: ~65. kg/m3
Scale height: 15.9 km
Average temperature:737 K
Diurnal temperature range: ~0
Wind speeds: 0.3 to 1.0 m/s (surface)
Mean molecular weight: 43.45 g/mole
Atmospheric composition :
Major: 96.5% Carbon Dioxide (CO2), 3.5% Nitrogen (N2)
Minor (ppm): Sulfur Dioxide (SO2) - 150; Argon (Ar) - 70; Water (H2O) - 20;
Carbon Monoxide (CO) - 17; Helium (He) - 12; Neon (Ne) - 7
Mars:
Mars was once thought to be the best bet for Extra terrestaral life on it.With the more modern day telescopes this was dismised as wrong, but there was still the possibility that life may have started but was now dormant,the Viking probes were sent to confirm this,but they found no traces of any form of life alive,dormant or even dead.Two viking lander probes were landed on the planet,they showed a waste land ,varying from dust to large rockes the size of houses.They confirmed that the planet had a thin atmosphere.The planet is also prone to large sand storms,which were seen by the probes as well as seen from the Viking probe orbiters. Mars can be seen as a red star,with a good scope it is possible to see detail on the disc,these vary in colour.The markings are red and black these move over a few days and can be identified using a map of Mars.If you have a large telescope,a larger telescope is an advantage when looking at the detail and once found in the telescope shows a red disc.Mars has pole caps made mostly of frozen carbon dioxide,these vary in size as Mars has season similar to our planet.Mars also has river beds,canals,craters and volcanoes River Bed and canals may have been caused by water that flooded in the when the surface was warmer.At the moment it may be solid under the surface of Mars Valleys, these are larger canals,caused by tectonic activity and are listed in Latin as "Valles" so they will in this book be classed as valleys.The largest is "Valles Marineris" this a canyon 150 to 700 km's in width and 4,500 km's in length.the largest of them is Olympus Mons it is 500 km's in diameter and 25 km's high . Mars has a few fairly large volcanoes, there are some small volcanoes.Some observers have reported seeing sand storms on the planet,these have now been seen by the viking orbiter.
During opposition a superior can be observed throughout the night.The visibilty after conjunction with the Sun runs like this
Day 0:Conjunction Mars with the Sun.
Day:54 Mars appears in the morning sky.
Day 353:Retrogression of Mars begins.
Day 390:Mars in opposition with the Sun.
Day 427:Retrogression ends.
Day 726:Mars dissappears in the evening sky.
Day 104:Mars disappears from the morning sky.
Day 780:Next conjunction.Mars is a dead planet it has a surface temperature of-120 degrees C to +25 degrees° C.The surface is covered in deep red iron-oxide dust and there are many rocks spread over the surface.Mars atmosphere is made up of 95% Carbon Dioxide,2% Nitrogen and 1-2% Argon and other gases,including Oxygen and water vapour.Mars largest angular distanex maps of the canals.People thought that Martians had built them to direct water from the polar caps,they were wrong.Mars has been visited by many probes,Mariner 9 made its flight by.Then the probes Viking 1 and 2 landed on the planet they were mini laboratories which made many tests.One was to search for life,they found nothing at all.It was also visited by a path finder probe,this was a small mobile probe,which did follow up work from the Viking probes it checked the make up of some of the rocks found on the surface of the planet.A few other probes sent to Mars have failed at some point of thier mission.This has been a major set back as well as embarrassment for NASA.Mars has two satellites Phobos and Deimos they are probably rogue asteroids caught by Mars gravity.
General Information:
Mars has a sidereal Period 687 Earth days and a Rotational Period 24 hr 37 mins Mean distance from the Sun is 230 million km/140 million miles.The equatorial diameter is 6,790km/4,220 miles,and has 2 moons.
| Name. |
Diameter(km.)
| Magnitude. |
| I Phobes. |
24 X
20 X
18. |
11.3. |
| II Deimos. |
16 X
12 X
10. |
14.8. |
The Moons of Mars.
Mars Atmosphere:
Surface Pressure: ~6.1 mb (variable) [6.9 mb to 9 mb (Viking 1 Lander site)]
Surface Density: ~0.020 kg/m3
Scale height: 11.1 km
Average temperature: ~210 K
Diurnal temperature range: 184 K to 242 K (Viking 1 Lander site)
Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites)
Mean molecular weight: 43.34 g/mole
Atmospheric composition:
Major : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7%
Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08%
Minor (ppm): Water (H2O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2.5;
Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3;
Xenon (Xe) - 0.08
Jupiter:
This planet is the first of the gas giants and is the largest of all the planets in our solar system. Jupiter can be seen at certain times of the year as a very bright star,it can be seen in a small telescope when some detail can be seen.A larger telescope will show lots of detail.The red spot can be seen,a larger telescope makes it stick out.There is a chance that on a clear night when the air is steady you can see it in a small telescope,but it is an advantage to have a larger telescope.It is also possible to see the four largest moons,these will be seen as four stars moving around the planet, they cause several interesting phenomena these will be explained later.As a superior planet Saturn is visible all night during opposition.Its visibility,beginning with the conjunction with the Sun.
Day 0:Conjunction with the Sun.
Day 13:Jupiter appears in the morning sky.
Day 140:Retrogression of Jupiter begins.
Day 200:the planet is in opposition with the Sun.
Day 260:Retrogression ends.Day 386:Jupiter dissappears in the evening sky.
Day 399:Next conjunction.Jupiter is made of gases,mainly hydrogen and helium.As you descend into the clouds the pressure turns the hydrogen and helium into a liquid,further down they turn to metallic hydrogen and helium.In the centre there is probably a rock core.Jupiter is a failed star,if it had been slightly larger heat and pressure would have built up in the centre,this would have been the start of nuclear fusion and a star would have been born. The cloud shows many different colours along many different shapes,there is a guide below to help identify the different shapes.
Bright(W)objects.
SPOT:a small,bright round spot.
SPTR:a small,shiny spot surrounded by a dark ring.
OVAL:An oval feature of medium or long size,fairly bright,wel; bounded;often found in the equatorial zone.
BAY:a large indentation,usually half oval at the edge of a dark band.
NICK:a small,semicircular notch at the edge of a band,often somewhat brighter than the adjacent zone.
GAP:a rather wide,weakened,or missing part in a band.
STRK:a bright,very oblong spot;when appearing in a dark band,it may look like part of a tear.
AREA:an extended,bright,irregularly region.
SECT:a particularly bright section of a band or a zone.
Dark(D)objects.
SDER:a small,very dark spot surrounded by a bright ring.
SPOT:any single spot ont oblong.
SECT:a noticeably darker section of a band or zone.
BAR:dark oblong or barrel-shaped spot.
PROJ:something akin to a prominence at the edge of a band,which may also be darker than the main part of the band.Shapes vary,the dents may be rounded or peaks.
VEIL:an extended homogeneously smooth dark,region sometimes occurring in the zones or in polar regions.
FEST:a dark "fiber" or garland crossing zone.One end of it or both may originate from a dark condensation in the band.
COL:a column-shaped dark area in a zone,either perpendicular to it or somewhat tilted.Such columns are occasionally seen in STrK or SEBZ.
DIST:disturbance:a dark,extended area,more or less well defined containing often very fine detail in irregular distribution and unusual shapes.
STRK:a very oblong,dark,stripe-shaped object.
SHAD:the shadow of a moon.
The planet is broken into 17 zones.
A chart below will help you identify them.Jupiter has more than 16 moons.As stated earlier,four are visible easily, they orbit the planet, they are Io,Europa,Ganymede and Callisto.These four moons appear as stars that move round the planet.The motion of these moons causes some interesting phenomena .A:Transit,this is where a moon goes in front of the planet and cast a shadow on the face of the planet.B:Eclipse,this is where a moon goes into,or comes out of the shadow of the planet.So it will appear or disappear suddenly.This is due to the position of Jupiter in relation to the Sun and when Jupiter is at a low tilt during the shadow is cast across the equatorial plane and this causes the phenomena.C:Opposition,this is where a moon will appear or disappear behind the limb of the planet.D:Conjunction,this is where moons will come close together or may pass in front of each other.Many probes have visited the planet these were Pioneer 10, it arrived on the 4th of December 1973,Pioneer 11,arrived on the 3rd of December 1974,Voyager 1 arrived on the 5th of March and the 2nd arrived on the 9th March 1979.The space probes have provided essential information about the atmosphere of the planet.The two Voyager found that Jupiter has three very thin rings.These ring can not be seen from the Earth.
| Ring (name). |
Radius(km.) |
| Halio. |
>100,000. |
| Main. |
>122,000. |
| Gossamer. |
>129,000. |
The 3 ring's of Jupiter.
Jupiter has also been visited by a space Galileo.The probe arrived in December 1995.This has taken many images of the planet despite the fact that the height gain antenna failed to open,this probe also has dropped a probe into Jupiter atomsphere.In 1994 a Comet called Schoemaker-Levy 9This was broken into many parts by the gravitational forces after it passed Jupiter.On its next pass it was calculated that it would strick Jupiter.This happened on the 16th July when the first part hit Jupiter,leaving a mark.This was the first hit of 17,some hits left no mark where as others left a mark bigger than the Earth.The last bit struck on the 22nd of July.The marks were seen for many rotations of the planet and as time went on they spread out over the cloud cover of the planet before disappearing.
General Information:
Jupiters sidereal period is 11.86 Years,and has a period of 9 hr 55mins.Its mean distance from the Sun is 778 Million km/483 million miles.Its equatorial diameter is 142,980km/89,350 miles and has 16 moons.
| Name. |
Diameter(km.)
| Magnitude. |
| I Io. |
3659 eq. |
5.0. |
| II Europa. |
3138. |
5.3. |
| III Ganymede. |
5262. |
4.6. |
| IV Callisto. |
4800. |
5.6. |
| V Amalthea. |
270 x 170 x 150. |
14.1. |
| VI Hamalia. |
180. |
14.8. |
| VII Elara. |
80. |
16.7. |
| VIII Pasiphae. |
40. |
17.0. |
| IX Sinope. |
30. |
18.3. |
| X Lysithea. |
20. |
18.4. |
| XI Carme. |
30. |
18.0. |
| XII Ananke. |
20. |
18.9. |
| XIII Leda. |
10. |
20.2. |
| XIV Thebe. |
110 x 90. |
15.7. |
| XV Adrastea. |
24 x 20 x 16. |
19.1. |
| XVI Metis. |
40. |
17.5. |
|
The Moons of Jupiter.
Additional Information:
A new moon was found in 1999 it is known as S/1999 J1 is about 3 miles across,making it the smallest moon ever found.As well being one of the smallest moons,it is one of a group moving in the opposite direction to most of the overs.It will be named once its orbit has been worked out by astronomers.
Jupiters Atmosphere:
Surface Pressure: >>100 bars
Average temperature: ~129 K
Temperature at 1 bar: ~165 K
Density at 1 bar: ~0.16 kg/m3
Wind speeds:
Up to ~150 m/s (<30 degrees latitude) or
Up to ~40 m/s (>30 degrees latitude)
Scale height: 27 km
Mean molecular weight: 2.22 g/mole
Atmospheric composition
Major: Molecular hydrogen (H2) - 89.8% (2.0%); Helium (He) - 10.2% (2.0%)
Minor (ppm): Methane (CH4) - 3000 (1000); Ammonia (NH3) - 260 (40);
Hydrogen Deuteride (HD) - 28 (10); Ethane (C2H6) - 5.8 (1.5);
Water (H2O) - ~4 (varies with pressure)
Aerosols: Ammonia ice, water ice, ammonia hydrosulfide
Saturn:
Saturn will appear as a bright star again.The brightness of Saturn is dependent on its distance from the Earth.Like Jupiter it's atmosphere is contains mainly Hydrogen then there is Metallic hydrogen followed by liquid Hydrogen,then a rocky core.Saturns surface temperature is -130 degrees C with Saturn a great deal of energy is radiated from the centre of the planet.This probably happens because there are strong ascending currents and efficient mixing of the atmosphere.The cause of the high speed of the current the equator.As a superior planet,Saturn is visible all night during opposition.It's visibility,begining with the conjunction with the Sun.
Day 0:Conjunction with the Sun.
Day 18:Saturn appears in the morning sky.
Day 125:Retrogression of Saturn begins.
Day 189:Saturn in opposition with the Sun.
Day 253:Retrogression ends.
Day 360:Saturn dissappears in the evening sky.
Day 378:Next conjunction.Saturn is like Jupiter it appears as a star in the sky,it is fairly bright and is not visible all year round, but as for all the planets at certain times of the year it is viable. Saturn is the second biggest planet,it is a gas giant planet just like Jupiter,it is made up of the same gases but the amounts of gases vary.As Saturn is made up of gas it is prone to get spots on the surface. Saturns main moon being Titan will appear as a star in a fairly large telescope.Most of the moons are very faint but as stated Titan,is fairly easy to find.The moon is Titan it has a magnitude of 8.3 and can be found quite easily.The other moons are Mimas,Enceladus,Tethys,Dione,and Rhea these are visible in a large telescope as stars.Saturn is an interesting planet to look at because of its rings which can be seen in most telescopes.The rings are made of different size rooks and ice balls.The rings are about one hundred miles wide.Saturn axis is tilted,because the rings lie around its equator,they incline as the planet tilts.This means the rings change greatly depending on what time of year they are being veiwed.The rings appear to change depending how the Earth and Saturn are placed in respect to each other. The rings also at times are in our line of site this means we are unable to see them.The rings also affect the brightness of Saturn when fully open Saturn will appear brighter as we see the light reflected of the rings.The equatorial plane which contains the rings,is inclined againstits orbit by 26° degrees and against its ecliptic plane by 28° degrees. This means that for 15 years the northern side will be seen by the observer then after 15 years the southern side will be seen.
This picture shows how the rings may appear.
The rings angle phases will never exceed 6° degrees.To see the ring you do not need a large telescope,should be able to see them in 3 ich telescope with out any problems,if you use a larger telescope you see will see division in the rings.
| Ring(name). |
Radius(km.) |
| D ring. |
>66,900. |
| C inner edge. |
74,658. |
| Titan ringlet. |
77,871. |
| Maxwell ringlet. |
87,491. |
| B innere edge. |
91,975. |
| B outer edge. |
117,507. |
| Cassini Division. |
No Data |
| A inner edge. |
122,340. |
| Encke gap. |
133,589. |
| A outer edge. |
136.775 |
| F ring centre. |
140,374. |
| G ring center. |
170,000. |
| E inner edge. |
~180,000. |
| E outer edge. |
~480,000. |
The 14 ring's of Saturn.
It is advisable that the observer prepares a set of stencils that has the rings on it set at the right angle so as to give an accurate reparation of the rings at the time when the observation is to be made.Like Jupiter it has belts but they are less pronounced .They to have cloud structure just like Jupiter.Over time the rings of Saturn open up as the planet moves in relation to the Earth,this causes the ring to cast a shadow on the planet,you will need a fairly large telescope to see this shadow. Like Jupiter, the same phenomena (eclipse,transits etc.).Happen but you will need an aperture of +25 cm's to see them.The phenomena as seen when the rings are edge on.The planet like Jupiter was visted by the two voyager probes Voyager 1 arrived on November 6th 1980,while Voyager 2 arrived mid summer 1981.A new mission called the Cassini probe,it is due to reach Saturn 2004.
Genreal Information:
The cloud top temperature is -120 degrees° C Saturns sidereal Period is 29.5 years with a Rotational period 10hr 40 mins.Its Distance from the Sun is 1,430 million km/886 million miles,and has a equatorial diameter 120,540km/74,900 miles and has 18 moons.
| Name. |
Diameter(km.)
| Magnitude. |
| I Mimas. |
421 x 395 x 385. |
12.9. |
| II Enceladus. |
512 x 495 x 488. |
11.7. |
| III Tethys. |
1046. |
10.2. |
| IV Dione. |
1120. |
10.4. |
| V Rhea. |
1528. |
9.7. |
| VI Titan. |
5150. |
8.3. |
| VII Hyperion. |
410 x 260 x 220. |
14.2. |
| VIII Iapetus. |
1460. |
11.9. |
| IX Phoebe. |
220 x 200 x 160. |
16.5. |
| X Janus. |
194 x 190 x 154. |
14.5. |
| XI Epimetheus. |
138 x 110 x110. |
15.5. |
| XII Helene. |
35 x 32 x 30. |
18.5. |
| XIII Telesto. |
30 x 25 x 15. |
18.5. |
| XIV Calypso. |
30 x 16 x 16. |
18.7. |
| XV Atlas. |
37 x 34 x 27. |
18. |
| XVI Prometheus. |
.148 x 100 x 68 |
16.5. |
| XVII Pandora. |
110 x 88 x 62. |
18. |
| XVI Pan |
20. |
20. |
The Moons of Saturn.
Saturnian Atmosphere:
Surface Pressure: >>100 bars
Average temperature: ~97 K
Temperature at 1 bar: ~134 K
Density at 1 bar: ~0.19 kg/m3
Wind speeds: Up to ~400 m/s (<30 degrees latitude) or
Up to ~150 m/s (>30 degrees latitude)
Scale height: 59.5 km
Mean molecular weight: 2.07 g/mole
Atmospheric composition
Major: Molecular hydrogen (H2) - 96.3% (2.4%); Helium (He) - 3.25% (2.4%)
Minor (ppm): Methane (CH4) - 4500 (2000); Ammonia (NH3) - 125 (75);
Hydrogen Deuteride (HD) - 110 (58); Ethane (C2H6) - 7 (1.5)
Aerosols: Ammonia ice, water ice, ammonia hydrosulfide
Uranus:
This planet is made up of 88 per cent hydrogen and 12 per cent helium,at lower parts of the planets,the clouds are made up of methane and other hydrocarbons.Its atmosphere is 11,000km's deep.Uranus:this planet it is a challenge to see this planet,but it is possible.Some observers with telescopes with an apertures of 25 cm or above are large enough to see some shading on the disc,this has now been dismissed but some limb darking can be seen.While observing the observer maybe able to see a greenish colour disc.It is possible to take pictures of the planet as well as the two largest moons,Titania and Oberon which reach 14th magnitude.The other three largest moons are harder to pick up on most amateur thescope.Ariel and Umbriel are about +16th magnitude and Miranda only reaches a magnitde of +17th.Uranus is the third planet to have rings.The rings were discovered while astronomers watched an occultation in 1977,by the star Libra.They watched the star and it appeared to blink.The observers concluded there must be five rings.The pass of the Voyager probe of the planet found five more rings.
There is one ununuasl thing about Uranus,that is that the planets and its moon axis is tilled on its side at 98° degrees.The reason for this could be due to a major collision during the formation of the solar system.
Configuration of the planet relative to the Sun.
There are other reason to believe this happeaned one is that the moons show signs of being broken up many times.Uranus was found in 1781 by F.W.Herschel, Uranus is known to have 15 moons, the best moon showing is Miranda found in 1948 by G.P.Kuiper. Maranda seems to be a jumble of large blocks of rock,this is said to show that it may have been up at some point in the solar system past.William Herschel found the two largest moons in 1789,named Oberon and Titania.The English astronomer William Lassell found Ariel and Umbriel in 1851.During the flight by of Voyager 2 in 1986 8 more moons were found.The probe passed at a distance of 93,000km's.
General Information:
Uranus has a sidereal Period 84 Earth years,and a rotational period 17 hrs 14 mins.Its mean distance from the Sun is 2,870 million miles/1,780 million miles.The planets equatorial diameter is 51,120km/31,760 miles and has 18 moons.
| Name. |
Diameter(km.)
| Magnitude. |
| I Ariel. |
1,162 X
1,156 X
1,155. |
14.2. |
| II Umbriel. |
1,169. |
14.8. |
| III Titania. |
1,578. |
13.7. |
| IV Oberon. | 1,523. |
13.9. |
| V Miranda. |
481 X
468 X
466. |
16.3. |
| VI Cordelia. |
26. |
24.1. |
| VII Ophelia. |
30. |
23.8. |
| VIII Bianca. |
42. |
23.0. |
| IX Cressida. |
62. |
22.2. |
| X Desdemina. |
54. |
22.5. |
| XI Juliet. |
84. |
21.5. |
| XII Portia. |
108. |
21.0. |
| XIII Rosalind. |
54. | 22.5. |
| XIV Belinda. |
66. |
22.1. |
| XV Puck. |
154. |
20.2. |
| S/1986 U10. |
40. |
No Data. |
S/1997 U1
Caliban. |
~80. |
No Data. |
S/1997 U2
Sycorax. |
~160. |
No Data. |
The Moons of Uranus.
Uranian Atmosphere
Surface Pressure: >>100 bars
Average temperature: ~58 K
Temperature at 1 bar: ~76 K
Density at 1 bar: ~0.42 kg/m3
Wind speeds: 0-200 m/s
Scale height: 27.7 km
Mean molecular weight: 2.64 g/mole
Atmospheric composition
Major: Molecular hydrogen (H2) - 82.5% (3.3%); Helium (He) - 15.2% (3.3%)
Methane (CH4) - ~2.3%
Minor (ppm): Hydrogen Deuteride (HD) - ~148
Aerosols: Ammonia ice, water ice, ammonia hydrosulfide, methane ice(?)
Neptune:
To see a disc of the planet with a magnification of over 300X,but no surface detail can ever be seen.The colour of the disc is seen to be blueish-green.It is possible to photograph the planet as well as the largest moon +13.6,but success will be limited .Neptune was not found in a telescope until 1846 on the 25 September by Johann Galle after a search by many astronomers Galle found by using after following the pridiction of U.Leverrier. In 1989 on August the 25th after the fly by of the Voyager 2 space probe,much was learn't about the planet.The probe passed at a distance of 29,240km,it most important discovery was the "Great Dark Spot",this is a massive cyclone that has white clouds on its edge called "Cirrus".Recent pictures by the Hubble Space Telescope show that this feature has gone,no one is shore if it will return in the future.The Voyager probe also showed other smaller light and dark spots,as well as other clouds and band structure.The planet was thought to have rings as well,the probe has cofirmed this.There are Six rings around Neptune.
| Ring(name). |
Radius(km.) |
| Galle(1989 N3R). |
41,9O0. |
| LeVerrier(1989 N2R). |
53,200. |
| Lassell(1989 N4R). |
53,200 |
| Arago(1989 N4R). |
57,200 |
| Unnamed. |
61,950 |
| Adams(1989 N1R). |
62,800. |
The 6 ring's of Neptune.
Some parts of the rings are formed by "arcs",these are parts of incomplete rings.The chart below show the arcs in Adams ring.
| Ring Arc. |
Radius(km.) |
| Courage. |
62,900. |
| Liberté. |
62,900. |
| egalité 1. |
62,900 |
| egalité 2. |
62,900 |
| Fraternité(1989 N4R). |
62,900 |
Arcs in Adam rings.
Neptunes 8 moon,Triton is the largest with a diameter of 1760 km it was discoverd by Lassell in 1846 and as a retograde orbit,this means it rotates in a different direction to which the planet rotates.Triton is the coldest object in the Solar System.It has volcanoes spew material into the moons thin atmosphere.The second biggest moon is Nereld and was discovered by Kuiper in 1949,the other six were found by the probe.
General Information:
Neptune has a Sidereal Period of 164.79 Earth years and a surface temperature -210 degrees C.It has a rotational period 16hr 7 mins with a mean distance from the Sun of 4,450 million km/2,790 million miles.Equatorial width 29,530 km/30,780 miles it also has 8 moon.
| Name. |
Diameter(km.)
| Magnitude. |
| I Triton. |
2,705. | 13.5. |
| II Nereid. |
340. | 18.7. |
| III Naiad. |
60. | 24.7. |
| IV Thalassa. |
80. | 23.8. |
| V Despina. |
160. | 22.6. |
| VI Galatea. |
160. | 22.3. |
| VII Larissa. |
210
x
180. | 22.0. |
| VIII Proteus. |
420. | 20.3. |
The Moons of Neptune.
Neptunian Atmosphere:
Surface Pressure: >>100 bars
Average temperature: ~58 K
Temperature at 1 bar: ~72 K
Density at 1 bar: ~0.45 kg/m3
Wind speeds: 0-200 m/s
Scale height: 19.1 - 20.3 km
Mean molecular weight: 2.53 - 2.69 g/mole
Atmospheric composition
Major: Molecular hydrogen (H2) - 80.0% (3.2%); Helium (He) - 19.0% (3.2%);
Methane (CH4) 1.5% (0.5%)
Minor (ppm): Hydrogen Deuteride (HD) - ~192; Ethane (C2H6) - ~1.5
Aerosols: Ammonia ice, water ice, ammonia hydrosulfide, methane ice(?)
Pluto:
This planet can only be seen with a large telescope as a star,a detailed drawing or photograph showing its position one day then another showing it position a few days later will confirm you saw Pluto as it position will have changed.Pluto is only in reach of more experienced observers. Ths planet was found in 1930 by an American astronomer Clyde Tombaugh the calculations that had been the cause for astronomers to look for the planets were in errors and only the work by Tombaugh's found the planet. Pluto has a moon called Charon it is only 12,240 miles away from pluto and found in 1978 .Over the past year the Hubble space telecope has seen brighter and darker areas on the disc of the planet indicating higher and lower features on the planet.At certain points Plutos orbit passes inside Neptunes orbit so not making it the furthest planet.This happens for about 20 years,and last happened between 1979 and 1999.NASA records show that on 11 February 1999 at 11:22 UT (6:22 a.m. EST), Pluto passed Neptune as the furthest planet from the Sun once again and will remain so until 5 April 2231.
General Informtion:
Sidereal Perod 248.54 Earth years Temperture-220 degrees C Rotatinal Period 6 days 9hrs Mean distance from sun 5,900 million km/3,700 million miles Volume ? Mass .0022 Density 2.03 Moons 1
| Name. |
Diameter(km.)
| Magnitude. |
| I Charon. |
>1186. |
16.8. |
The Moon of Pluto.
Pluto Atmosphere:
Surface Pressure: ~3 microbar
Average temperature: ~50 K
Scale height: ~60 km
Mean molecular weight: ~16-25 g/mole
Atmospheric composition: Methane (CH4), Nitrogen (N2)
Space Probes.
Missions to Mercury:.
Mariner 10-NASA Mission to Venus and Mercury (1962-75).
Missions to Venus:.
Magellan - NASA Venus Radar Mapping Mission (1989-1994).
Pioneer Venus - NASA Orbiter/Probes to Venus (1978-1992).
Galileo - NASA Mission to Jupiter (Venus flyby - 1990).
Vega 1 - Soviet mission to Venus and Comet Halley (Venus flyby - 1985).
Vega 2 - Soviet mission to Venus and Comet Halley (Venus flyby - 1985).
Venera - Soviet Venus Missions (1961-1983).
Mariner 10 - NASA Mission to Venus and Mercury (1973-1975).
Mariner 5 - NASA Venus flyby (1967).
Mariner 2 - NASA Venus flyby (1962).
Future Missions:
VESPER - Proposed Discovery Orbiter to Venus (2004).
Missions to Mars:
Mars Polar Lander - NASA attempted lander to Mars (1999)
Deep Space 2 - NASA attempted penetrator mission to Mars (1999).
Mars Climate Orbiter - NASA attempted orbiter to Mars (1998)
Nozomi (Planet-B) - ISAS (Japan) orbiter to Mars (1998)
Mars Global Surveyor - NASA Mars orbiter (1996).
Mars Pathfinder - NASA lander and rover to Mars (1996).
Mars 96 - Russian attempted mission to Mars (1996).
Mars Observer - NASA attempted mission to Mars (1992).
Phobos - Soviet missions to Mars (1988).
Viking - NASA orbiters/landers to Mars (1975).
Mars 6 - Soviet Mars lander (1973).
Mars 5 - Soviet Mars orbiter (1973).
Mariner 9 - NASA Mars orbiter (1971).
Mars 3 - Soviet Mars orbiter and lander (1971).
Mars 2 - Soviet Mars orbiter and lander (1971).
Mariner 7 - NASA Mars flyby (1969).
Mariner 6 - NASA Mars flyby (1969).
Mariner 4 - NASA Mars flyby (1964).
Future Missions to Mars:
Mars Surveyor 2001 Orbiter - NASA Orbiter Mission to Mars (2001).
Mars Surveyor 2001 Lander and Rover - Cancelled NASA Lander/Rover Mission to Mars (2001).
Mars Express - ESA Mars Orbiter and Lander (2003).
Mars 2003 - NASA Orbiter or Rover to Mars (2003).
Mars 2005 - NASA Mission to Mars (2005).
Missions to Jupiter:
Cassini - NASA/ESA Mission to Saturn via Jupiter.
Galileo - NASA Mission to Jupiter.
Voyager - NASA Missions to Jupiter, Saturn, Uranus, Neptune, and beyond
Ulysses - NASA/ESA Mission to study the solar wind via Jupiter.
Pioneer 10 - NASA Jupiter flyby (1973).
Pioneer 11 - NASA Jupiter flyby (1974).
Future Missions:
Europa Orbiter - NASA Proposed Europa Orbiter (2003).
INSIDE Jupiter - Proposed Discovery Orbiter to Jupiter (2004).
Missions to Saturn:
Cassini - NASA/European Space Agency Mission to Saturn.
Huygens - NASA/European Space Agency Mission to Saturn's satellite Titan.
Voyager - NASA Missions to Saturn(1980-1981).
Pioneer 11 - NASA Saturn flyby (1979).
Missions to Uranus:
Voyager2 - NASA Missions to Uranus
Missions to Neptune:
Voyager2 NASA Missions to Neptune.
Future Missions to Pluto:
Pluto-Kuiper Express (NASA Flyby Mission to Pluto).
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