Kyushu is the third largest island of Japan's five main islands and the most southerly of the four largest islands. In the past, it has been known as Kyūkoku, Chinzei and Tsukushi-no-shima. The historical regional name Saikaidō referred to Kyushu and its surrounding islands. In the 8th-century Taihō Code reforms, Dazaifu was established as a special administrative term for the region. As of 2018, Kyushu has a population of 14,311,224 and covers 36,782 square kilometres.
Earth is the third planet from the Sun and the only astronomical object known to harbor life. About 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is covered with water, mostly by oceans, seas, gulfs, and other salt-water bodies, but also by lakes, rivers, and other fresh water, which together constitute the hydrosphere.
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Of these, Kepler-186f is closest in size to Earth, with 1.2 times Earth's radius, and it is located towards the outer edge of the habitable zone around its red dwarf host star. The potentially habitable planet TOI 700 d is only 100 light years away.
Jupiter is the largest, at 318 Earth masses, whereas Mercury is the smallest, at 0.055 Earth masses. The planets of the Solar System can be divided into categories based on their composition: Terrestrials: Planets that are similar to Earth, with bodies largely composed of rock: Mercury, Venus, Earth and Mars. At 0.055 Earth masses, Mercury is ...
Dynamics, Structure and Evolution of the Earth and Planets; ... Kyushu University. Series D, Earth and Planetary Sciences. Volume XXXV, No. 1, March, 2021 Download (5 ...
Current and on-going research programs extend from the geophysics of the Earth's deep interior, through near-surface geological and geochemical studies, to ocean, atmosphere, geomagnetosphere, and solar-planet system sciences. The department also encompasses research into the origin and evolution of life and our planet.
Earth is the third planet from the Sun. It is the only planet known to have life on it. The Earth formed around 4.5 billion years ago. It is one of four rocky planets on the inside of the Solar System. The other three are Mercury, Venus, and Mars. The large mass of the Sun makes Earth move around it, just as the mass of Earth makes the moon move around it. Earth also turns around in space, so that different parts face the Sun at different times. Earth goes around the Sun once for every 365 1 ...
The Planets, Op. 32, is a seven-movement orchestral suite by the English composer Gustav Holst, written between 1914 and 1916.Each movement of the suite is named after a planet of the solar system and its corresponding astrological character as defined by Holst.
The realization that Earth is a planet, and a planet among many others was established “fairly” recently, in the 17thcentury – this realization came through by the combined forces of ancient philos...Plato correctly deduced that the Earth is spherical but this idea would take root and be proven much later.The name “Earth” – is at least 1.000 years old, and it is a Germanic word which simply translates to “the ground.” It is not known who came up with it but it is the only planet that wasn’t named af...However, the Greek equivalent to Earth is Gaia – terra mater – mother Earth, and Roman equivalent was Tellus – the fertile soil.
- Key Facts & Summary
- Distance, Size and Mass
- Orbit and Rotation
- Structure – Geology
- Axial Tilt
The Earth is believed to have formed around 4.5 billion years ago. The duration for this formation has been estimated to have lasted about 10 to 20 million years. The theory states that a solar nebula partitions a volume out of a molecular cloud by gravitational collapse which begins to spin and flatten into a circumstellar disk. The planets grow out of that disk through gravity pulling swirling dust and gas. Slowly, the Earth’s atmosphere and oceans were formed by volcanic activity and outgassing. It is believed that water vapor condensed into the oceans being augmented by water and ice from asteroids, protoplanets, and comets. The atmospheric greenhouse kept the oceans from freezing when the newly formed Sun had only 70% of its current luminosity. When the Earth’s magnetic field was established it helped to prevent the atmosphere from being stripped away by the solar wind. A crust formed when the molten outer layer of Earth cooled to form a solid. There are two models who propose...
Earth is the third planet from the Sun, at a distance of 1 AU or 147 million km / 91 million mi. It is situated in the goldilocks zone where temperatures are just right for liquid water to exist and for life to evolve. Depending upon their current orbital positions, either Venus or Mercury are the closest planets to Earth. It has an equatorial radius of 6.371 km / 3.958 mi, and a polar radius of 6.356 km / 3.949 mi, meaning it is not completely spherical but rather bulged at the equator due to rotation. The diameter of Earth is around 12.742 km / 7.917 mi being the fifth largest planet from the solar system, and the largest of the terrestrial planets (Venus, Mercury, Mars). The Earth is so big that if it were hallowed, almost 50 moons could fit inside it. Earth has a mass of about 6.6 sextillion tons and a volume of about 260 billion cubic miles / 1 trillion cubic kilometers. It has the biggest mass out of all the terrestrial planets and the greatest density out of all the planets –...
The Earth makes a complete rotation on its axis once every 23.9 hours. It takes Earth 265,25 days to complete one trip around the Sun – year. In order for calendars to maintain their consistency with this orbit, every 4 years one day is added – this is called a leap day – as well as a leap year. Earth’s orbital speed averages 29.78 km/s (107,208 km/h; 66,616 mph), which is fast enough to cover the planet’s diameter in 7 minutes and the distance to the Moon in 4 hours.
Earth has four major main layers: an inner core at the center, an outer core enveloping it, mantle, and crust. Since it has the greatest density out of all the planets in the solar system – 5.51 g/cm³ – and a gravity of 9.807 m/s² or 1 g the Earth’s core is solid. It is made of iron and nickel about 759 miles / 1.221 kilometers in radius. The temperatures at the core have been estimated to be around 9.800 degrees Fahrenheit / 5.400 degrees Celsius. This is hotter than the surface of the Sun. Together with the inner core, Earth also has an outer core, with the crust being the mantle and the thickest layer. It is a viscous mixture of molten rock about 1.800 mi / 2.900 km thick and has the consistency of caramel. The outermost layer – Earth’s crust – goes about 19 mi / 30 km deep on average on land. But at the bottom of the ocean, the crust is thinner and extends about 3 mi / 5 km from the seafloor to the top of the mantle. The crust in a sense floats on the mantle due to lower density...
The surface area of Earth is about 197 million square miles / 510 million square kilometers. Around 71% of the surface is covered by water and 29% by land. The water is 3% fresh and 97% salted. Of that 3% freshwater, over 2% is frozen in ice sheets and glaciers meaning that less than 1% is freshwater found in lakes, rivers, and the underground. In regards to land, the continent of Asia covers about 30% of all the land, having around 60% of the world’s population. The Earth is divided into 7 continents that constantly “move” several centimeters every year. In about 250 million years about four fundamental scenarios for the formation of the next supercontinent have been hypothesized: Novopangea, Pangea Ultima, Aurica and Amasia. Novopangea seems the most likely scenario based on current evaluations. The Americas would collide with the northward drifting Antarctica, and then into the already collided Africa-Eurasia. The highest altitude – elevation – on Earth is Mount Everest at 8,848m...
The atmosphere of Earth is a layer of gas above the crust. It is not solid and thus it fades away with height. The line between Earth’s atmosphere and space is set at 100 km / 62 miles up. It is called the Kármán line. Technically, anyone, who goes above it is an “astronaut.” The atmosphere by volume is about 78% nitrogen, 21% oxygen, 1% argon, and the rest an assortment of trace gases. Water vapor is also present, almost all of it below a height of about 8-15 km/ 4.9 – 9 mi. This part of the atmosphere is the warmest at the bottom, creating convection in the air that in turn creates currents of rising air. They carry water, forming clouds, which in turn is why we have weather. The ozone layer is situated at a height of 25 km / 15.5 mi on average. This is a molecule of oxygen that absorbs very well solar ultraviolet light. This type of light is dangerous to biological molecules thus the ozone layer is critical for our protection and survival. The atmosphere of Earth can be divided i...
Earth’s outer core is made from liquid metal which conducts electricity. The liquid convects, and this motion generates magnetic fields. Earth’s rotation helps organize this motion into huge cylindrical roles that align with the Earth’s axis. This generates a magnetic field similar to a bar magnet, with a magnetic north pole and south pole. This field surrounds the Earth and deflects most of the charged particles from the solar wind. Without this geomagnetic field, the solar wind would directly hit Earth’s atmosphere eroding the air away. Mars doesn’t have a strong magnetic field, and it is believed that because of this its atmosphere is mostly vanquished. Some solar wind particles are trapped by Earth’s magnetic field and are channeled down into the atmosphere. There, they are slammed into air molecules about 150 km / 93.2 mi up. This energizes the molecules, which respond by emitting light in different colors. This glow is called aurora. The auroras happen near the geomagnetic pol...
The Earth orbits around the Sun with one pole constantly tilted towards it. This tilt results in how much light reaches a given point on the surface of Earth. Earth’s axis is tilted towards the ecliptic of the Sun at approximately 23.4 degrees. This is responsible for Earth’s seasonal changes and the diurnal cycle.
Earth is currently the only known planet with water on the surface. Referred to as the “Blue Planet”, Earth’s hydrosphere consists chiefly of oceans, inland seas, lakes, rivers, and underground waters down to a depth of 2.000 m / 6.600 ft. The deepest underwater location is the Challenger Deep of the Mariana Trench in the Pacific Ocean with a depth of 10.911 m / 35.799 ft. The mass of the oceans represents about 1/4400 of Earth’s total mass.