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4.56 Billion years ago, Solar Nebula forms
A concentration of hydrogen gas and dust swirling around our young Sun creates solar nebula. The start of the solar system -
4.56 Billion Years Ago, Planetesimals form
Planetesimals Form
Baby planets less than a few kilometers across form. -
4.56 billion years ago Terrestrial planets form.
Mercury, Venus, Earth, and Mars form in the hot inner solar system -
4.56 billion years ago Gas planets formed
Jupiter, Saturn, Uranus, and Neptune form in the cooler, outer solar system. -
4.5 billion years ago
Formation of Earth's Moon Earth was hit by a Mars-sized planet. Debris blown into space around Earth eventually joined and formed our Moon. -
4.4 Billion years ago
Initial Crust on Earth
Early Earth was hot. Eventually the molten outer layers cooled, forming a crust. -
4.2 Billion Years Ago
Formation of Earth's Early Atmosphere and Oceans
Volcanos spewed gases — including water vapor — into the atmosphere. When things cooled down enough the water vapor condensed as liquid water in our oceans. -
200 Million Years Ago
Saturn Gets Its Rings
Scientists believe that Saturn has these rings because it’s so big and has lots of moons, meaning it has a stronger pull of gravity so it pulls things towards it which makes the rings. -
402 years ago Keplers discoveries
In 1609 Kepler discoverd the laws of the planetary motion. His first law was; The orbit of every planet is an ellipse with the Sun at one of the two foci.
The second law; A line joining a planet and the Sun sweeps out equal areas during equal intervals of time.
And the third law which was created 13 years later was; The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. -
284-369 years ago properties of gravity and inertia discovered
Somewhere between 284-369 years ago, Sir Isaac Newton discovered that gravity and inertia keep the planets in their orbits. Inertia means that it stays in the same place. -
Uranus Characteristics
Uranus was the first planet to be discovered in history. The core of Uranus is probably composed of liquid rock. Then, farther up, the liquid rock slowly gives way to an ocean made mostly of hydrogen, helium, and water, with small amounts of ammonia and methane. Uranus is the only planet rotates on its side. This produces the strangest seasons of any planet. Scientists aren't sure why, but they think that a large body smashed into it with such force that it pushed the planet over on it's side. -
Neptune Characteristics
Neptune, like its twin, Uranus, has an atmosphere composed of hydrogen, helium, methane, and ammonia. The methane creates the blue color. Neptune's internal structure is also the same as that of Uranus. Neptune was the ancient Roman god of the sea. Neptune has 13 known moons. -
Period: to
Gas Giant Planets
Information on all of the gas giants -
Jupiter characterisitics.
Jupiter has a huge atmosphere, a liquid mantle, and a liquid / solid core, with no definite boundary between the layers. The core of Jupiter is probably composed of liquid rock, at a temperature as high as 43,000°F. The core is small relative to the planet, about 20% of its radius, but it is still fifteen times heavier than the Earth. Jupiter is named after the Roman god of lightning, who was also the King of the gods. Jupiter is definitely king over the planets. -
Saturn characteristics
Saturn is a gas giant. It's structure is very similar to Jupiter's. The core is composed liquid rock. Next comes a layer of liquid hydrogen. It is under such high pressure that the nature of the hydrogen changes, and is able to conduct electricity like metal. This generates the planet's magnetic field. It is the least dense of all the planets. Saturn is named for the Roman Lord of the Rings. -
Mercury Characteristics
Mercury is a nearly airless world that is heavily cratered, and it is only 40% larger than our moon. The side towards the sun is a sizzling 662°F while the side turned away from the sun is -292 °F. Mercury is, in many ways, one of the least understood planets in our solar system, since it was only visited once in the 1970's. It is hoped that the MESSENGER craft will provide many clues to help decipher Mercury's history when it arrives back in 2011. -
Venus characteristics
For years, Venus was called Earth's Sister Planet, and much popular science fiction literature was devoted to what might lie below the huge clouds. All that changed once scientists were able to measure what those clouds were made of: Poisonous gases. Venus is named after the ancient Roman goddess of love. When scientists first spotted it, they saw swirls of clouds, and thought that they hid a world of beauty that was Earth-like, and would contain life. They couldn't have been more wrong. -
Period: to
Terrestrial Planets
Characteristics of all of the terrestrial planets. -
Mars Characteristics
Mars is about half the size of our planet, Earth. It's thin atmosphere is slowly being blown away by the sun's solar wind. Mars is also home to one of the longest (more than 4,000 km) canyon systems in the solar system called Valles Marineris. Mars is the most Earth-like planet in the solar system (except for in size and therefore surface gravity. Because of this, several scientists believe that Mars can be formed into a planet inhabitable by humans. -
Earth Characteristics
The Earth is the only planet, that we currently know of, capable of sustaining life. Several factors led to the development of life: First, Earth had to be at a temperate distance from its host star. This means that the planet needs to be at a distance from the star to allow liquid water to exist, and for the temperature range to be not too extreme. Second, Earth has an atmosphere, and that atmosphere had (and has) a chemical makeup that allows the development of life.Third, Earth has water. -
Pluto
Although Pluto was discovered in 1930, limited information on the distant object delayed a realistic understanding of its characteristics. Pluto is the second largest known dwarf planet and tenth largest orbiting the Sun. From its time of discovery in 1930 to 2006 it was considered to be the ninth planet in the solar system. -
Comets
Comets are sometimes called "dirty snowballs" because they are mixtures of ices and dust. The nucleus of a comet, which is usually a few kilometers in diameter, is the only active part of a comet when it is further from than Sun than the orbit of Jupiter. Once the comet nears the Sun, the ices contained in the nucleus turn to gas and plasma, creating a long, visible tail that extends from the nucleus. -
Asteroids
Asteroids, sometimes referred to as minor planets, are rocky, metallic bodies that revolve around the Sun, usually in a region known as the Asteroid Belt. The Asteroid Belt lies between the orbits of Mars and Jupiter and contains millions of asteroids. 70,000 have been identified.Although most asteroids revolve within the Asteroid Belt, a few asteroids have eccentric orbits that wander outside the region between Mars and Jupiter. Some asteroids even cross Earth's orbit. -
Meteoroids
Meteoroids are small chunks of stone that are capable of intersecting Earth's orbit. If a meteoroid enters the Earth's atmosphere, it is known as a meteor. If the meteor doesn't entirely disintegrate in the atmosphere and strikes the surface of the Earth, it is called a meteorite. Meteors create a streak of light when they enter the Earth's atmosphere. The meteors travel at high speeds when they enter the atmosphere and the friction they encounter heats the surrounding area.
