The Sun It is the star at the center of the Solar System. About three quarters of its mass consists of hydrogen, while the rest is mostly helium. The energy of this sunlight supports almost all life on Earth by photosynthesis, and drives Earths climate and weather
Parts of the Sun1. Core – sun’s center2. Photosphere – the first layer of the sun3. Chromosphere – innermost layer of the sun’s atmosphere4. Corona – extensive outer layer of the sun’s atmosphere5. Sunspots – dark areas on the surface of the sun6. Solar flares – flashes of bright light are visible on earth7. Prominence – a giant column of hot gases formed in the chromosphere that extends to the corona
Stars A star is a massive, luminous ball of plasma held together by gravity.
Constellations collection of stars linked together to represent a person, animal or object. is an internationally defined area of the celestial sphere.
Zodiacal Family Aquarius, the water bearer Aries, the ram Cancer, the crab Capricorn, the goat Gemini, the twins Leo, the lion Libra, the scales Pisces, the fish Sagittarius, the archer Scorpius, the scorpion Taurus, the bull
Supergiants Have diameters up to 1000 times the diameter of the sun Examples: Rigel, Betelgeuse, a nd Antares
Stars By using a spectroscope, astronomers have found out that stars have similar composition, the most common is hydrogen. He, O, Ne, C are other elements
Stars Blue stars are the hottest and youngest stars followed by white, yellow, red- orange, and red as the oldest stars.
Stars New stars are born from the gases in the nebulae that clump together because of gravity
NEBULA a region or cloud of interstellar dust and gas
Stars are born in nebulae. Huge clouds of dust and gas collapse under gravitational forces, forming protostars. These young stars undergo further collapse, forming main sequence stars. Stars expand as they grow old. As the core runs out of hydrogen and then helium, the core contracts and the outer layers expand, cool, and become less bright. This is a red giant or a red super giant (depending on the initial mass of the star). It will eventually collapse and explode. Its fate is determined by the original mass of the star; it will become either a black dwarf, neutron star, or black hole.
Our Solar SystemOur solar system is made up of: Sun Planets Their moons Asteroids Comets
Inner PlanetsThe inner four rocky planets at the center of the solar system are: Mercury Venus Earth Mars
What is a planet?The definition of planet set in 2006 by the International Astronomical Union (IAU) states that in the Solar System a planet is a celestial body that: is in orbit around the Sun, has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and has "cleared the neighbourhood" around its orbit.
The PlanetsMercury is the planet that is closest to our Sun. Neptune is the farthest. Remember the order of the planets like this:My Very Educated Mother Just Showed Us Nothing which meansMercury Venus Earth Mars Jupiter Saturn Uranus Neptune
MercuryWhat are Mercury‘s features? smallest planet nearest to the sun one Mercury-year is a quarter Earth-year Mercury is very difficult to be spotted with the naked eye Mercury has no moons
VenusWhat are Venus‘ features? it is a medium sized planet, 2.5 times as large as Mercury second nearest to the sun Venus is very well visible to the naked eye, always close to the sun before sunrise or after sunset Venus has no moons
EarthWhat are Earth‘s features? it is a medium sized planet, a bit larger than Venus (probably) the only planet with liquid water in our Solar System the Earth has one moon (probably) the only planet with intelligent life in our Solar System
MarsWhat are Mars‘ features? it is a small sized planet, half as large as Earth Mars is well visible to the naked eye Mars has two moons: Phobos and Deimos Mars has been visited by robotic vehicles: Pathfinder, Spirit and Opportunity the question for (former) life on Mars is still unsolved
JupiterWhat are Jupiter‘s features? it is the largest planet of the Solar System, more than 1.300 Earths could fit inside Jupiter is well visible to the naked eye The Great Red Spot on its surface is a giant storm as wide as three Earths Jupiter has 63 moons! (the largest are Io, Callisto, Ganymede and Europa)
SaturnWhat are Saturn‘s features? it is the second-largest planet of the Solar System, only a bit smaller than Jupiter Saturn is well visible to the naked eye the famous rings can be seen with small telescopes Saturn has at least 34 moons! (recently a probe landed on Jupiter‘s moon Titan)
UranusWhat are Uranus‘ features? it is medium sized planet of the Solar System it is quite far away but still can be spotted with small telescopes like Saturn, Uranus has a system of rings
NeptuneWhat are Neptune‘s features? it is medium sized planet of the Solar System, only a little bit smaller than Uranus it is quite far away but still can be spotted with small telescopes Neptune has four rings and at least 13 moons
PlutoWhat are Pluto‘s features? it is already a dwarf planet Since Pluto is far away and so small, you need a medium-sized professional telescope or a good amateur telescope to spot it. No one knows what Pluto looks like – it‘s too far away and too small. The picture in the background is an artist‘s rendition.
Pluto Pluto is now classified as a dwarf planet. It is unusual because it is not a gas giant and it does not seem to be terrestrial. The motion of Pluto’s orbit suggests that Pluto may have been one of Neptune’s moons at one time. Pluto also has a moon called Charon which is about the same size as Pluto.
Planetary SummaryClosest to Brown crater 59 daysthe Sun 0.386 0 Chunks of rock none To orbit Sun2nd from Hot enough to A 1.7 KM high 0.72 0 CO2, N2the Sun melt lead Volcano Volcanoes,3rd from 1 1 Soil and Water N 2, O 2 hurricanesthe Sun Reddish Volcanoes,4th from 0.5326 2 CO2, N2the Sun coloured soil glaciers5th from Coloured Bands, Winds,the Sun 11 63 Great Red Spot H2, He, CH4 hurricanes6th from Surface temp. is H2, He, CH4 Windy, clothe Sun 10 33 About -180o udy7th from Polar hood over 500 km/hthe Sun 4 29 South pole H2, He, CH4 winds8th from 3.8 13 It’s blue. H2, He, CH4 Dark spotthe Sun9th from 0.186 3 Cold and rocky none Rotates onthe Sun side
Earth’s Moon Dry, airless, and barren world with extreme temperature The moon is actually moving away from earth at a rate of 1.5 inches per year. The moon is not round, but egg shaped with the large end pointed towards earth. The earth rotates about 1000 mph. By comparison, the moon rotates about 10 mph
Asteroids Small bodies Believed to be left over from the beginning of the solar system billions of years ago 100,000 asteroids lie in belt between Mars and Jupiter Largest asteroids have been given names
Meteoroids Small pieces of matter (some as grains of sand) that also orbit the sun When a meteoroid enters the earth’s atmosphere, friction causes it to heat up and glow (meteors) Some meteors that enter the earth’s atmosphere do not burn up and they land on earth (meteorites)
Comets Small icy bodies Travel past the Sun Give off gas and dust as they pass by
Halley’s Comet It passes the Earth every 76 years. Its last pass was in 1986
What is the difference between an asteroid, comet, and meteoroid? Asteroid:A relatively small, inactive body, composed of rock, carbon or metal, which is orbiting the Sun. Comet:A relatively small, sometimes active object, which is composed of dirt and ices. Comets are characterised by dust and gas tails when in proximity to the Sun. Far from the Sun it is difficult to distinguish an asteroid from a comet. Meteoroid:A small particle from an asteroid or comet orbiting the Sun.
Movements of the Earth Rotation – earth rotates on its axis which is tilted at an angle of 23.5O earth rotates towards the East Revolution – the entire trip around the sun; 365 days, 5 hours, 48 minutes, and 46 seconds
Terms to be remembered: Eclipse - an astronomical event that occurs when an object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer.
Terms to be remembered: Perigee – moon’s orbit is closest to Earth Apogee – moon’s orbit is farthest to the Earth Umbra – small inner shadow Penumbra – large outer shadow
Space News Space exploration is one of the most fascinating features of modern times. Why do you think it is important to explore the space?