Solar System

Solar System

Gravitationally Bound System

The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, the dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.

Solar Storm: August Sun Eruption PHOTOS Show Coronal Mass Ejection Up Close

Published: 09/07/2012 10:09 AM EDT on SPACE.com

NASA spacecraft watching the sun have captured jaw-dropping pictures and video of a giant filament of super-hot plasma reaching up from the star’s surface and erupting into space.

The filament was made of solar material that was ejected from the sun during an intense solar storm on Aug. 31. Flares are caused by increased magnetic activity on the surface of our star, and are becoming more common as the sun approaches a phase of peak activity in 2013.

The filament was spotted by NASA’s Solar Dynamics Observatory, was likely gigantic, scientists say. The spacecraft and other sun-watching observatories recorded an amazing video of the giant solar filament and the solar eruption, called a coronal mass ejection (or CME), that followed.

Facts about the sun:

Moons: Eris, 225088 Gonggong, 762 Pulcova Trending

Surface temperature: 5,778 K

Mean radiance (Isol): 2.009×107 W·m−2·sr−1

Escape velocity (from the surface): 617.7 km/s; 55 × Earth

Equatorial surface gravity: 274 m/s2; 28 × Earth

The Sun—the heart of our solar system—is a yellow dwarf star, a hot ball of glowing gases.

Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest particles of debris in its orbit. Electric currents in the Sun generate a magnetic field that is carried out through the solar system by the solar wind—a stream of electrically charged gas blowing outward from the Sun in all directions.

The connection and interactions between the Sun and Earth drive the seasons, ocean currents, weather, climate, radiation belts and aurorae. Though it is special to us, there are billions of stars like our Sun scattered across the Milky Way galaxy.

The Sun is a yellow dwarf star, a hot ball of glowing gases at the heart of our solar system. Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest particles of debris – in its orbit. The connection and interactions between the Sun and Earth drive the seasons, ocean currents, weather, climate, radiation belts and auroras. Though it is special to us, there are billions of stars like our Sun scattered across the Milky Way galaxy.

The Sun has many names in many cultures. The Latin word for Sun is “sol,” which is the main adjective for all things Sun-related: solar.

Size and Distance

Size and Distance

With a radius of 432,168.6 miles (695,508 kilometers), our Sun is not an especially large star—many are several times bigger—but it is still far more massive than our home planet: 332,946 Earths match the mass of the Sun. The Sun’s volume would need 1.3 million Earths to fill it.

This illustration shows the approximate size of Earth compared to the Sun. Image Credit: ESA & NASA

The Sun is 93 million miles (150 million kilometers) from Earth. Its nearest stellar neighbor is the Alpha Centauri triple star system: Proxima Centauri is 4.24 light years away, and Alpha Centauri A and B—two stars orbiting each other—are 4.37 light years away. A light year is the distance light travels in one year, which is equal to 5,878,499,810,000 miles or 9,460,528,400,000 kilometers.

 

Orbit and Rotation

Orbit and Rotation

The Sun, and everything that orbits it, is located in the Milky Way galaxy. More specifically, our Sun is in a spiral arm called the Orion Spur that extends outward from the Sagittarius arm. From there, the Sun orbits the center of the Milky Way Galaxy, bringing the planets, asteroids, comets and other objects along with it. Our solar system is moving with an average velocity of 450,000 miles per hour (720,000 kilometers per hour). But even at this speed, it takes us about 230 million years to make one complete orbit around the Milky Way.

The Sun rotates as it orbits the center of the Milky Way. Its spin has an axial tilt of 7.25 degrees with respect to the plane of the planets’ orbits. Since the Sun is not a solid body, different parts of the Sun rotate at different rates. At the equator, the Sun spins around once about every 25 days, but at its poles the Sun rotates once on its axis every 36 Earth days.

Formation

The Sun and the rest of the solar system formed from a giant, rotating cloud of gas and dust called a solar nebula about 4.5 billion years ago. As the nebula collapsed because of its overwhelming gravity, it spun faster and flattened into a disk. Most of the material was pulled toward the center to form our Sun, which accounts for 99.8% of the mass of the entire solar system.

Like all stars, the Sun will someday run out of energy. When the Sun starts to die, it will swell so big that it will engulf Mercury and Venus and maybe even Earth. Scientists predict the Sun is a little less than halfway through its lifetime and will last another 6.5 billion years before it shrinks down to be a white dwarf. – https://solarsystem.nasa.gov/solar-system/sun/in-depth/

Our Planet Earth

Our home planet is the third planet from the Sun, and the only place we know of so far that’s inhabited by living things. While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal.

Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating estimation and other evidence, Earth formed over 4.5 billion years ago. Earth’s gravity interacts with other objects in space, especially the Sun and the Moon, which is Earth’s only natural satellite. Earth orbits around the Sun in 365.256 solar days, a period known as an Earth sidereal year. During this time, Earth rotates about its axis 366.256 times, that is, a sidereal year has 366.256 sidereal days.

Earth’s axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth. The gravitational interaction between Earth and the Moon causes tides, stabilizes Earth’s orientation on its axis, and gradually slows its rotation. Earth is the densest planet in the Solar System and the largest and most massive of the four rocky planets.

 

Earth’s outer layer (lithosphere) is divided into several rigid tectonic plates that migrate across the surface over many millions of years. About 29% of Earth’s surface is land consisting of continents and islands. The remaining 71% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which all together constitute the hydrosphere. The majority of Earth’s polar regions are covered in ice, including the Antarctic ice sheet and the sea ice of the Arctic ice pack. Earth’s interior remains active with a solid iron inner core, a liquid outer core that generates Earth’s magnetic field, and a convecting mantle that drives plate tectonics.

 

Within the first billion years of Earth’s history, life appeared in the oceans and began to affect Earth’s atmosphere and surface, leading to the proliferation of anaerobic and, later, aerobic organisms. Some geological evidence indicates that life may have arisen as early as 4.1 billion years ago. Since then, the combination of Earth’s distance from the Sun, physical properties and geological history have allowed life to evolve and thrive. In the history of life on Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinctions. Over 99% of all species that ever lived on Earth are extinct. Estimates of the number of species on Earth today vary widely; most species have not been described. Over 7.7 billion humans live on Earth and depend on its biosphere and natural resources for their survival.

  • https://en.wikipedia.org/wiki/Earth

Earth’s crust is about 19 miles deep on average on land. At the bottom of the ocean, the crust is thinner and extends about 3 miles from the sea floor to the top of the mantle.

Inner Core

Earth’s inner core is a solid sphere made of iron and nickel metals about 760 miles in radius. Its temperature is as high as 9,800 degrees Fahrenheit.

Outer Core

The outer core is about 19 miles thick and made of iron and nickel fluids

Mantle

Mantle The mantle is Earth’s thickest layer. This hot mixture of molten rock is about 1,800 miles thick and has the consistency of caramel.

Crust

Earth’s crust is about 19 miles deep on average on land. At the bottom of the ocean, the crust is thinner and extends about 3 miles from the sea floor to the top of the mantle.

Surface

Earth has volcanoes, mountains, and valleys. Earth’s lithosphere, which includes the crust (both continental and oceanic) and the upper mantle, is divided into huge plates that are constantly moving.

Atmosphere

Earth’s atmosphere is 78 percent nitrogen, 21 percent oxygen, and 1  percent other gases like argon, carbon dioxide, and neon.