Download Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and

Solar system
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It includes:
the satellites of the planets; numerous comets, asteroids, and meteoroids; and the
interplanetary medium. The Sun is the richest source of electromagnetic energy
(mostly in the form of heat and light) in the solar system. The Sun's nearest known
stellar neighbor is a red dwarf star called Proxima Centauri, at a distance of 4.3 light
years away. The whole solar system, together with the local stars visible on a clear
night, orbits the center of our home galaxy, a spiral disk of 200 billion stars we call
the Milky Way. The Milky Way has two small galaxies orbiting it nearby, which are
visible from the southern hemisphere. They are called the Large Magellanic Cloud
and the Small Magellanic Cloud. The nearest large galaxy is the Andromeda Galaxy.
It is a spiral galaxy like the Milky Way but is 4 times as massive and is 2 million light
years away. Our galaxy, one of billions of galaxies known, is traveling through
intergalactic space.
The planets, most of the satellites of the planets and the asteroids revolve around the
Sun in the same direction, in nearly circular orbits. When looking down from above
the Sun's north pole, the planets orbit in a counter-clockwise direction. The planets
orbit the Sun in or near the same plane, called the ecliptic. Pluto is a special case in
that its orbit is the most highly inclined (18 degrees) and the most highly elliptical of
all the planets. Because of this, for part of its orbit, Pluto is closer to the Sun than is
Neptune. The axis of rotation for most of the planets is nearly perpendicular to the
ecliptic. The exceptions are Uranus and Pluto, which are tipped on their sides.
Composition Of The Solar System
The Sun contains 99.85% of all the matter in the Solar System. The planets, which
condensed out of the same disk of material that formed the Sun, contain only 0.135%
of the mass of the solar system. Jupiter contains more than twice the matter of all the
other planets combined. Satellites of the planets, comets, asteroids, meteoroids, and
the interplanetary medium constitute the remaining 0.015%. The following table is a
list of the mass distribution within our Solar System.







Sun: 99.85%
Planets: 0.135%
Comets: 0.01% ?
Satellites: 0.00005%
Minor Planets: 0.0000002% ?
Meteoroids: 0.0000001% ?
Interplanetary Medium: 0.0000001% ?
Interplanetary Space
Nearly all the solar system by volume appears to be an empty void. Far from being
nothingness, this vacuum of "space" comprises the interplanetary medium. It includes
various forms of energy and at least two material components: interplanetary dust and
interplanetary gas. Interplanetary dust consists of microscopic solid particles.
Interplanetary gas is a tenuous flow of gas and charged particles, mostly protons and
electrons -- plasma -- which stream from the Sun, called the solar wind.
The solar wind can be measured by spacecraft, and it has a large effect on comet tails.
It also has a measurable effect on the motion of spacecraft. The speed of the solar
wind is about 400 kilometers (250 miles) per second in the vicinity of Earth's orbit.
The point at which the solar wind meets the interstellar medium, which is the "solar"
wind from other stars, is called the heliopause. It is a boundary theorized to be
roughly circular or teardrop-shaped, marking the edge of the Sun's influence perhaps
100 AU from the Sun. The space within the boundary of the heliopause, containing
the Sun and solar system, is referred to as the heliosphere.
The solar magnetic field extends outward into interplanetary space; it can be
measured on Earth and by spacecraft. The solar magnetic field is the dominating
magnetic field throughout the interplanetary regions of the solar system, except in the
immediate environment of planets which have their own magnetic fields.
The Terrestrial Planets
The terrestrial planets are the four innermost planets in the solar system, Mercury,
Venus, Earth and Mars. They are called terrestrial because they have a compact, rocky
surface like the Earth's. The planets, Venus, Earth, and Mars have significant
atmospheres while Mercury has almost none. The following diagram shows the
approximate distance of the terrestrial planets to the Sun.
The Jovian Planets
Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets,
because they are all gigantic compared with Earth, and they have a gaseous nature
like Jupiter's. The Jovian planets are also referred to as the gas giants, although some
or all of them might have small solid cores. The following diagram shows the
approximate distance of the Jovian planets to the Sun.
Solar System Animation

Formation of the Solar System.
Views of the Solar System
Our Milkyway Galaxy
This image of our galaxy, the Milky Way, was taken with NASA's Cosmic
Background Explorer's (COBE) Diffuse Infrared Background Experiment (DIRBE).
This never-before-seen view shows the Milky Way from an edge-on perspective with
the galactic north pole at the top, the south pole at the bottom and the galactic center
at the center. The picture combines images obtained at several near-infrared
wavelengths. Stars within our galaxy are the dominant source of light at these
wavelengths. Even though our solar system is part of the Milky Way, the view looks
distant because most of the light comes from the population of stars that are closer to
the galactic center than our own Sun. (Courtesy NASA)
Our Milky Way Gets a Makeover
Like early explorers mapping the continents of our globe, astronomers are busy
charting the spiral structure of our galaxy, the Milky Way. Using infrared images
from NASA's Spitzer Space Telescope, scientists have discovered that the Milky
Way's elegant spiral structure is dominated by just two arms wrapping off the ends of
a central bar of stars. Previously, our galaxy was thought to possess four major arms.
This artist's concept illustrates the new view of the Milky Way, along with other
findings presented at the 212th American Astronomical Society meeting in St. Louis,
Mo. The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen
attached to the ends of a thick central bar, while the two now-demoted minor arms
(Norma and Sagittarius) are less distinct and located between the major arms. The
major arms consist of the highest densities of both young and old stars; the minor
arms are primarily filled with gas and pockets of star-forming activity.
The artist's concept also includes a new spiral arm, called the "Far-3 kiloparsec arm,"
discovered via a radio-telescope survey of gas in the Milky Way. This arm is shorter
than the two major arms and lies along the bar of the galaxy.
Our sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located
between the Sagittarius and Perseus arms. (Courtesy NASA/JPL-Caltech)
Spiral Galaxy, NGC 4414
The majestic galaxy, NGC 4414, is located 60 million light-years away. Like the
Milky Way, NGC 4414 is a giant spiral-shaped disk of stars, with a bulbous central
hub of older yellow and red stars. The outer spiral arms are considerably bluer due to
ongoing formation of young, blue stars, the brightest of which can be seen
individually at the high resolution provided by the Hubble camera. The arms are also
very rich in clouds of interstellar dust, seen as dark patches and streaks silhouetted
against the starlight. (Courtesy NASA/STSCI)
Obliquity of the
Eight Planets
This illustration shows the obliquity of the eight planets. Obliquity is the angle
between a planet's equatorial plane and its orbital plane. By International
Astronomical Union (IAU) convention, a planet's north pole lies above the ecliptic
plane. By this convention, Venus, Uranus, and Pluto have a retrograde rotation, or a
rotation that is in the opposite direction from the other planets. (Copyright 2008 by
Calvin J. Hamilton)
The Solar System
During the past three decades a myriad of space explorers have escaped the confines
of planet Earth and have set out to discover our planetary neighbors. This picture
shows the Sun and all nine planets of the solar system as seen by the space explorers.
Starting at the top-left corner is the Sun followed by the planets Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. (Copyright 1998 by Calvin
J. Hamilton)
Sun and Planets
This image shows the Sun and nine planets approximately to scale. The order of these
bodies are: Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and
Pluto. (Copyright Calvin J. Hamilton)
Jovian Planets
This image shows the Jovian planets Jupiter, Saturn, Uranus and Neptune
approximately to scale. The Jovian planets are named because of their gigantic
Jupiter-like appearance. (Copyright Calvin J. Hamilton)
The Largest Moons and Smallest Planets
This image shows the relative sizes of the largest moons and the smallest planets in
the solarsystem. The largest satellites pictured in this image are: Ganymede (5262
km), Titan (5150 km), Callisto (4806 km), Io (3642 km), the Moon (3476 km),
Europa (3138 km), Triton (2706 km), and Titania (1580 km). Both Ganymede and
Titan are larger than planet Mercury followed by Io, the Moon, Europa, and Triton
which are larger than the planet Pluto. (Copyright Calvin J. Hamilton)
Diagram of Portrait Frames
On February 14, 1990, the cameras of Voyager 1 pointed back toward the Sun and
took a series of pictures of the Sun and the planets, making the first ever "portrait" of
our solar system as seen from the outside. This image is a diagram of how the frames
for the solar system portrait were taken. (Courtesy NASA/JPL)
All Frames from the Family Portrait
This image shows the series of pictures of the Sun and the planets taken on February
14, 1990, for the solar system family portrait as seen from the outside. In the course of
taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images
of the inner solar system from a distance of approximately 6.4 billion kilometers (4
billion miles) and about 32° above the ecliptic plane. Thirty-nine wide angle frames
link together six of the planets of our solar system in this mosaic. Outermost Neptune
is 30 times further from the Sun than Earth. Our Sun is seen as the bright object in the
center of the circle of frames. The insets show the planets magnified many times.
(Courtesy NASA/JPL)
Portrait of the Solar System
These six narrow-angle color images were made from the first ever "portrait" of the
solar system taken by Voyager 1, which was more than 6.4 billion kilometers (4
billion miles) from Earth and about 32° above the ecliptic. Mercury is too close to the
Sun to be seen. Mars was not detectable by the Voyager cameras due to scattered
sunlight in the optics, and Pluto was not included in the mosaic because of its small
size and distance from the Sun. These blown-up images, left to right and top to
bottom are Venus, Earth, Jupiter, Saturn, Uranus, and Neptune. (Courtesy NASA/JPL)
The following table lists statistical information for the Sun and planets:
Distan Radiu Mass Rotati
#
Orbital Orbital Obliqui Densi
(Earth' on
ce
s
Moo Inclinati Eccentric
ty
ty
(AU) (Earth' s)
(Earth' ns
(g/cm
on
ity
3
s)
s)
)
332,80
25-36*
0
Sun
0
109
9
---
---
---
1.410
Mercu
ry
0.39
0.38
0.05
58.8
0
7
0.2056
0.1°
5.43
Venus
0.72
0.95
0.89
244
0
3.394
0.0068
177.4°
5.25
Earth
1.0
1.00
1.00
1.00
1
0.000
0.0167
23.45°
5.52
Mars
1.5
0.53
0.11
1.029
2
1.850
0.0934
25.19°
3.95
Jupite
r
5.2
11
318
0.411
16
1.308
0.0483
3.12°
1.33
Saturn
9.5
9
95
0.428
18
2.488
0.0560
26.73°
0.69
Uranu
s
19.2
4
17
0.748
15
0.774
0.0461
97.86°
1.29
Neptu
ne
30.1
4
17
0.802
8
1.774
0.0097
29.56°
1.64
Pluto
39.5
0.18
0.002
0.267
1
17.15
0.2482
119.6°
2.03
* The Sun's period of rotation at the surface varies from approximately 25 days at the
equator to 36 days at the poles. Deep down, below the convective zone, everything
appears to rotate with a period of 27 days.