Project Nila

MERCURY

Equatorial radius2,440 km

Equatorial inclination0.01

Mass3.301023 kg

Average density5.4 g/cm3

Rotational period58.6 days

Orbital period0.2408 years

Average distance from the Sun57.91 million km

Perihelion46 million km

Aphelion69.82 million km

Orbital eccentricity0.206

Orbital inclination7

Moons0

Mercury orbits closer to the Sun than any other planet, making it dry, hot, and virtually airless. Although the planets cratered surface resembles that of the Moon, it is believed that the interior is actually similar to Earths, consisting primarily of iron and other heavy elements. This composite photograph was taken in 1974 by Mariner 10, the first probe to study Mercury in detail.LikeEarthandmostother planets, Mercury turns counterclockwise (west to east) when seen from its north pole. Mercurys axis is almost perfectly vertical, unlike Earths axis, which is tilted 23.5 degrees. Radar observations of Mercury show that it rotates only once every 58.65 days, two-thirds of its period of revolution around the Sun. As a result, only three rotations of the planet occur during every two of its years. This relationship is called a 3:2 spin-orbit resonance. It is thought to be the result of differences in the pull of the Suns gravity on Mercury as the planet moves nearer and farther away in its orbit, an effect called solid body tidal forces.

SUN

Interior of the SunRegions of the Sun include the core, radiation zone, convection zone, and photosphere. Gases in the core are about 150 times as dense as water and reach temperatures as high as 16 million degrees C (29 million degrees F). The Suns energy is produced in the core through nuclear fusion of hydrogen atoms into helium. In the radiation zone, heat flows outward through gases that are about as dense as water. The radiation zone is cooler than the core, about 2.5 million degrees C (4.5 million degrees F). In the convection zone, churning motions of the gases carry the Suns energy further outward. The convection zone is slightly cooler, about 2 million degrees C (3.6 million degrees F), and less dense, about one-tenth as dense as water. The photosphere is much cooler, about 5500 C (10,000 F) and much less dense, about one-millionth that of water. The turbulence of this region is visible from earth in the form of sunspots, solar flares, and small patches of gas called granules.

VENUS



Mass4.871024 kg


Rotational period1-243



Perihelion107.5 million km



Orbital inclination3.39

Moons0

Venus is the brightest object in our sky, after the sun and moon. Swirling clouds of sulfur and sulfuric acid obscure Venuss surface and inhibited study of the planet from Earth until technology permitted space vehicles, outfitted with probes, to visit it. These probes determined that Venus is the hottest of the planets, with a surface temperature of about 460 C (about 860 F). Scientists believe that a greenhouse effect causes the extreme temperature, hypothesizing that the planets thick clouds and dense atmosphere trap energy from the sun.

Venus (planet),secondplanetindistance from the Sun, but the hottest planet in the solar system (hotter than Mercury). Its hellish surface has broiling temperatures that make rocks glow red under a crushing atmosphere that shrouds the planet in thick layers of clouds. Venus is nearly the same size as Earth, but takes 243 days to rotate on its axis in the opposite direction. It also lacks a magnetic field and a moon. Why conditions on Venus and Earth are so different remains a major puzzle for planetary scientists. Venus circles the Sun at a distance of 108 million km (67 million mi) in a little over seven months (about 225 days). The planet was named for Venus, the Roman goddess of beauty.

ExceptfortheSunand the Moon, Venus is the brightest object in the sky. It is often called the morning star when it appears in the east at sunrise, and the evening star when it is in the west at sunset. In ancient times the evening star was called Hesperus and the morning star Phosphorus, Eosphoros, or Lucifer.

EARTH



Mass5.971024 kg



Orbital period1 year






Moons1

An oxygen-rich and protective atmosphere, moderate temperatures, abundant water, and a varied chemical composition enable Earth to support life, the only planet known to harbor life. The planet is composed of rock and metal, which are present in molten form beneath its surface. The Apollo 17 spacecraft took this snapshot in 1972 of the Arabian Peninsula, the African continent, and Antarctica (most of the white area near the bottom).

Earth is made up of a series of layers that formed early in the planets history, as heavier material gravitated toward the center and lighter material floated to the surface. The dense, solid, inner core of iron is surrounded by a liquid, iron, outer core. The lower mantle consists of molten rock, which is surrounded by partially molten rock in the asthenosphere and solid rock in the upper mantle and crust. Between some of the layers, there are chemical or structural changes that form discontinuities. Lighter elements, such as silicon, aluminum, calcium, potassium, sodium, and oxygen, compose the outer crust.Earthisthethirdplanet from the Sun, after Mercury and Venus. The average distance between Earth and the Sun is 150 million km (93 million mi). Earth and all the other planets in the solar system revolve, or orbit, around the Sun due to the force of gravitation. The Earth travels at a velocity of about 107,000 km/h (about 67,000 mph) as it orbits the Sun. All but one of the planets orbit the Sun in the same planethat is, if an imaginary line were extended from the center of the Sun to the outer regions of the solar system, the orbital paths of the planets would intersect that line. The exception is the dwarf planet Pluto, which has an eccentric (unusual) orbit. Earth is the fifth largest planet in the solar system. Its diameter, measured around the equator, is 12,756 km (7,926 mi). Earth is not a perfect sphere but is slightly flattened at the poles. Its polar diameter, measured from the North Pole to the South Pole, is somewhat less than the equatorial diameter because of this flattening. Although Earth is the largest of the four planetsMercury, Venus, Earth, and Marsthat make up the inner solar system (the planets closest to the Sun), it is small compared with the giant planets of the outer solar systemJupiter, Saturn, Uranus, and Neptune. For example, the largest planet, Jupiter, has a diameter at its equator of 143,000 km (89,000 mi), 11 times greater than that of Earth. A famous atmospheric feature on Jupiter, the Great Red Spot, is so large that three Earths would fit inside it. Earth has one natural satellite, the Moon. The Moon orbits the Earth, completing one revolution in an elliptical path in 27 days 7 hour 43 min 11.5 sec. The Moon orbits the Earth because of the force of Earths gravity. However, the Moon also exerts a gravitational force on the Earth. Evidence for the Moons gravitational influence can be seen in the ocean tides. A popular theory suggests that the Moon split off from Earth more than 4 billion years ago when a large meteorite or small planet struck the Earth.

NEPTUNE



Mass1.021026 kg




Average distance from the Sun4.488 billion km.

Perihelion4.440 billion km.

Aphelion4.536 billion km.



Moons13

Eighthplanetindistance from the Sun, fourth largest planet in diameter, and third largest in mass in the solar system. Neptunes gravity has a major influence on the Kuiper Belt, a region of icy bodies in the outer solar system that is a source of comets and includes the dwarf planet Pluto, formerly counted as the ninth planet.Because of its great size and mass, scientists classify Neptune as one of the giant or Jovian (Jupiter-like) planetsalong with Jupiter, Saturn, and Uranus. Like Uranus, Neptune is also classified as an ice giant planet, mainly made of the ice-forming molecules water, ammonia, and methane as a liquid mixture above what is thought to be a rocky core. Its atmosphere is mainly hydrogen and helium, along with methane gas that gives the planet a blue-green color.From Voyager 2 spacecraft images, astronomers identified four rings of debris encircling Neptunes equator. These rings range in width from 15 km (9.3 mi) to 5,800 km (3,600 mi). All of these rings completely encircle the planet, but the outermost ring includes three or more arcs of concentrated debris, some of which had been detected from Earth before the Voyager 2 encounter. In 1998 a new infrared camera on the Hubble Space Telescope (HST) obtained the first new images of Neptune's mysterious ring-arcs since the 1989 Voyager 2 encounter. Astronomers had speculated that the gravitational pull from nearby moons caused smaller particles to form the concentrated debris arcs, but the new images showed that this theory is incorrect. Observations by the Earth-based Keck telescope, announced in 2005, showed that some of the ring-arcs have faded since the Voyager 2 encounter, indicating that the rings are features that change noticeably over time.Thirteen moons are known to orbit Neptune. Only two of these moonsTriton and Nereidwere directly observed from Earth prior to the 1990s. Triton was discovered in 1846 by British astronomer William Lassell, and Nereid was discovered in 1949 by Dutch-born American astronomer Gerard Kuiper. Scientists discovered another moon, Larissa, in 1981 when the moon occulted (moved in front of) a star, and they discovered five more moons of Neptune from images transmitted to Earth by the Voyager 2 spacecraft. Searches carried out with large Earth-based telescopes led to the discovery of 3 more moons in 2003 and 2 more in 2004, bringing the total to 13. These five additional moons are the smallest and most distant from Neptune of all the planets moons, and astronomers know little else about them. They may be asteroids captured by the pull of Neptunes gravity.The four innermost moons of Neptune are quite small, ranging in diameter from 58 km (36 mi) to 180 km (110 mi). From the closest to Neptune outward, these moons are Naiad, Thalassa, Despina, and Galatea. Larissa is the fifth moon in distance from Neptune. It is heavily cratered and irregular in shape. Its density, chemical composition, and internal structure are unknown. Proteus is the sixth moon out from Neptune. This satellite is the largest irregularly shaped moon in the solar system, measuring 436 km (262 mi) through its widest diameter and 402 km (241 mi) through its narrowest diameter.Triton is the seventh moon from Neptune and is the largest of the planets moons, measuring 2,700 km (1,700 mi) in diameter, larger than the dwarf planet Pluto. Triton, which consists of about one-quarter ice and three-quarters rock, has few craters on its surface, which suggests that this moon has undergone recent geological changes. It has a thin nitrogen atmosphere and a polar cap. Voyager 2 recorded geyser-like plumes erupting from its icy crust. Unlike any other large moon in the solar system, Triton has a retrograde (clockwise) orbit, meaning that it revolves around Neptune in the opposite direction that the planet rotates (counterclockwise). Its circular orbit is also tilted out of the plane of Neptune's equator by 157. Tritons odd orbit is a puzzle. The main moons of every other planet orbit nearly in the plane of the planets equator and in the same direction as the planet spins, retaining the motion of a rotating disk of debris around the planet from which the moons would have formed. One current theory is that Triton is actually a Kuiper Belt Object that was captured by Neptunes gravity. The stress of the capture may have heated Triton, partially melting its interior and surface, explaining its relatively young appearance. The event may also have disrupted the orbits of other moons around Neptune, including Nereid.Nereid is the eighth moon from Neptune and has an extremely elliptical orbit, varying in distance around Neptune from 1.4 million km (870,000 mi) to 9.6 million km (6 million mi). Voyager 2 did not pass near enough to Nereid to obtain detailed information.Astronomers have detected swarms of asteroids that share Neptunes orbit, similar to the Trojan asteroids that share Jupiters orbit. In both cases, the asteroids are found at points in the planets orbital path where the gravitational pull from the Sun and from the planet are balanced. These stable regions occur at points 60 degrees ahead and behind the planet as it orbits the Sun.

JUPITER



Mass1.901027 kg









Moons63

Jupiter is the largest of the planets, with a volume more than 1,300 times greater than that of Earth. Jupiters colorful bands are caused by strong atmospheric currents and accentuated by a dense cloud cover. The massive planet, upper right, is shown here with its four largest satellites: Io, upper left, Ganymede, lower left, Europa, center, and Callisto, lower right.Jupiter (planet), fifth planet from the Sun and the largest planet in the solar system. The fourth brightest object in Earths sky, after the Sun, the Moon, and Venus, Jupiter is more than three times brighter than Sirius, the brightest star. Due to its prominence in the sky, the Romans named the planet for their chief god, Jupiter.

In 1979, a camera on the Voyager 1 spacecraft used a long exposure with the line of sight passing through the equatorial region to determine that Jupiter has a thin ring. Three inner moons of Jupiter were also discovered from images taken by the Voyager spacecraft. These moons, named Metis, Adrastea, and Thebe, along with Amalthea, discovered in 1892, revolve around Jupiter at average distances of 128,000 km (79,500 mi), 129,000 km (80,000 mi), 222,000 km (138,000 mi), and 181,000 km (112,000 mi), respectively. They are dark and irregularly shaped. Amalthea is 135 km (84 mi) across its largest dimension, and the other three moons range from 10 to 50 km (6 to 31 mi) in diameter.

The ring is composed of three parts: a main ring, a halo, and an outer ring. The main ring is flat, about 7,000 km (4,300 mi) wide, and extends out to 128,500 km (79,800 mi), about twice the radius of Jupiter. A halo of charged particles, which are spread poleward by magnetic interactions, overlaps the main ring. A faint, outer, gossamer ring begins beyond the main ring and extends to the orbits of Amalthea and Thebe.

The ring and the four inner moons form a closely related system. In 1998 astronomers at Cornell University concluded that material scattered from the four inner moons is the source of the ring particles, and that the structure of the rings is determined by the dimensions and tilts of the orbits of the moons relative to Jupiter's equator. Dust is knocked off when micrometeoroids strike Jupiter's four innermost moons. Metis and Adrastea orbit Jupiter at the outer edge of the inner rings and sweep up material in their paths, acting as 'shepherds' to keep the outer edge of the ring sharp. Amalthea and Thebe, orbiting farther from Jupiter, supply material to sustain the outer gossamer ring.

SATURN



Mass5.691026 kg


Rotational period0.444 days?1


Average distance from the Sun1.435 billion kilometers

Perihelion1.352 billion kilometers

Aphelion1.517 billion kilometers



Moons60

This processed Hubble Space Telescope image shows the planets cloud bands, storms, and rings as they would appear to the human eye.Saturn,sixthplanetinorder of distance from the Sun, and the second largest in our solar system. Saturns most distinctive feature is a giant system of rings that surrounds the planet at its equator, stretching over twice the width of the planet itself. The first person to see the rings was the Italian scientist Galileo in 1610, using one of the earliest telescopes. Space probes have greatly increased our knowledge of Saturn, its rings, and its many moons. Flybys by the Pioneer and the Voyager probes led to the Cassini orbiter that began studying Saturn in detail in 2004. As seen from Earth, Saturn appears as a yellowish objectone of the brightest in the night sky. The planet is named for Saturn, the Roman god of agriculture.

URANUS



Mass8.681025 kg


Rotational period1-0.718 days


Average distance from the Sun2.857 billion kilometers

Perihelion2.719 billion kilometers

Aphelion2.996 billion kilometers



Moons27

The planet Uranus (the bright blue object) is surrounded by its five largest satellites clockwise from top left, Ariel, Umbriel, Oberon, Titania, and Miranda, in this collage created from photographs taken by the United States Voyager 2 spacecraft in 1986.

Uranuss blue-green color comes from the methane gas present in its cold, clear atmosphere. The dark shadings at the right edge of the sphere correspond to the day-night boundary on the planet. Beyond this boundary, Uranuss northern hemisphere remains in a four-decade-long period of darkness because of the way the planet rotates. Scientists compiled this view of Uranus from images returned from Voyager 2 in 1986, when the probe was 9.1 million km (5.7 million mi) away from the planet.

It is theseventhplanetindistance from the Sun, third largest planet in diameter, and fourth largest in mass in the solar system. Unlike other major planets, Uranus is tipped sideways on its axis of rotation. It experiences extreme seasons, and its 13 rings and 27 known moons revolve around its equator nearly vertically to the plane of its orbit around the Sun.

MARS



Mass6.421023 kg




Average distance from the Sun228 million km





Moons2

The most detailed information available about Mars has come from unpiloted spacecraft sent to the planet by the United States. From this data, scientists have determined that the planets atmosphere consists primarily of carbon dioxide, with small amounts of nitrogen, oxygen, water vapor, and other gases. Because the atmosphere is extremely thin, daily temperatures can vary as much as 100 Celsius degrees (190 Fahrenheit degrees). In general, surface temperatures are too cold and surface pressures too low for water to exist in a liquid state on Mars. The planet resembles a cold, high-altitude desert.Mars (planet), fourth planet in distance from the Sun in the solar system. Mars is of special scientific interest because of its similarities to Earth. It has an atmosphere with seasons and changing weather, and its surface shows evidence of ancient water and volcanoes. The length of its day and the tilt of its axis are similar to those of Earth. Mars takes about two years to circle the Sun at an average distance of 228 million km (141.7 million mi). The possibility of life on Mars, now or in the distant past, is one of the major questions in astronomy. More space probes have been sent to Mars than to any other planet. Mars is named for the Roman god of war. It is sometimes called the red planet because it appears fiery red in Earths night sky, the result of rusty, iron-oxide mineral dust that covers its surface.Marsisarelativelysmall planet, with a diameter of about 6,794 km (4,222 mi) or about half the diameter of Earth. Mars has about one-tenth Earths mass. The force of gravity on the surface of Mars is about three-eighths of that on Earth. Mars has twice the diameter and twice the surface gravity of Earths Moon. The surface area of Mars is almost exactly the same as the surface area of the dry land on Earth. Mars is believed to be about the same age as Earth, having formed from the same spinning, condensing cloud of gas and dust that formed the Sun and the other planets about 4.6 billion years ago.

Marshastwomoons,Phobos and Deimos, which are named after the sons of the Roman god Mars. These tiny bodies are heavily cratered, dark chunks of rock and may be asteroids captured by the gravitational pull of Mars. Phobos orbits Mars once in less than one Martian day, so it appears to rise in the west and set in the east, usually twice each day. Deimos has the more ordinary habit of rising in the east and setting in the west.

PROJECTIN SCIENCE

Submitted by:

Joanne Jane D. DesturaJules Emile Frederic DesturaGrade iv-a

Submitted to:

Ms. Carleen Yambao

THE SOLAR SYSTEM

Solar System,theSunandeverything that orbits the Sun, including the planets and their satellites; the dwarf planets, asteroids, Kuiper Belt Objects, and comets; and interplanetary dust and gas. The term may also refer to a group of celestial bodies orbiting another star (see Extrasolar Planets). In this article, solar system refers to the system that includes Earth and the Sun. Thedimensionsofthe solar system are specified in terms of the mean distance from Earth to the Sun, called the astronomical unit (AU). One AU is 150 million km (about 93 million mi). Estimates for the boundary where the Suns magnetic field ends and interstellar space beginscalled the heliopauserange from 86 to 100 AU from the Sun.Themostdistantknown body orbiting the Sun is the dwarf planet Eris, whose discovery was reported in July 2005. Eris is currently about 97 AU from the Sun. Another planetlike object in the outer solar system named Sedna is currently at 90 AU but will reach about 900 AU at the farthest point in its orbit thousands of years from now. Comets known as long-period comets, however, achieve the greatest distance from the Sun; they have highly eccentric orbits ranging out to 50,000 AU or more. (A comets period is how long it takes it to complete one revolution about the Sun.) They are members of the Oort cloud, a spherical shell of comet nuclei that surrounds the flat plane of planetary orbits at this enormous distance.Thesolarsystemwasthe only planetary system known to exist around a star similar to the Sun until 1995, when astronomers discovered a planet about 0.6 times the mass of Jupiter orbiting the star 51 Pegasi. Jupiter is the most massive planet in our solar system. Soon after, astronomers found a planet about 8.1 times the mass of Jupiter orbiting the star 70 Virginis, and a planet about 3.5 times the mass of Jupiter orbiting the star 47 Ursa Majoris. Since then, astronomers have found planets and disks of dust in the process of forming planets around many other stars. Most astronomers think it likely that solar systems of some sort are numerous throughout the universe.

THE NATURAL SATELLITE /MOON

Natural Satellite,abodyinspacethat orbits a larger body. The larger body is referred to as the satellites primary. Natural satellites that orbit planets are often called moons. Other objects in the solar system that sometimes have satellites include dwarf planets, Kuiper Belt Objects, centaurs, and asteroids. The term satellite is also used to refer to small galaxies that orbit larger galaxies.

Naturalsatellitesare of special interest to astronomers and planetary scientists because these objects provide clues to how the planets and the solar system formed. Studying the orbits of satellites also allows scientists to determine the mass and density of planets and other objects. A number of moons are important to astrobiologists as places where conditions might permit extraterrestrial life to exist. The International Astronomical Union (IAU) gives official names to natural satellites.

Documents

Project Nila