The terrestrial planets are composed of which of the following elements

In studying our Solar System over the course of many centuries, astronomers learned a great deal about the types of planets that exist in our universe. This knowledge has since expanded thanks to the discovery of extrasolar planets, many of which are similar to what we have observed here at home. For example, while hundreds of gas giants of varying size have been detected (which are easier to detect because of their size), numerous planets have also been spotted that are similar to Earth – aka. “Earth-like”. These are what is known as terrestrial planets, a designation which says a lot about a planet how it came to be. Definition: Also known as a telluric or rocky planet, a terrestrial planet is a celestial body that is composed primarily of silicate rocks or metals and has a solid surface. This distinguishes them from gas giants, which are primarily composed of gases like hydrogen and helium, water, and some heavier elements in various states. Remove All Ads on Universe Today Join our Patreon for as little as $3! Get the ad-free experience for life The term terrestrial planet is derived from the Latin “Terra” (i.e. Earth). Terrestrial planets are therefore those that are “Earth-like”, meaning they are similar in structure and composition to planet Earth. Artist’s concept for the range of Earth-like extrasolar planets that have been discovered in recent years. Credit: NASA/JPL Composition and Characteristics: All terrestrial planets have approximately the same type of stru...

The growth of planetesimals from smaller solid particles that collided and stuck together At first, accretion probably arose from electrostatic attractions, but as planetesimals grew larger their gravity allowed them to accrete more efficiently (as long as they didn't suffer collisions with similar-size planetesimals)

Astronomy 1101: Planets to Cosmos Planet Formation and Nucleosynthesis Key Ideas: The present-day properties of our Solar System hold important clues to its origin. Primordial Solar Nebula: • Process of the Sun's formation • Condensation of grains & ices From Planetesimals to Planets: • Aggregation of small grains into planetesimals • Aggregation of planetesimals into planets Terrestrial vs. Jovian planet formation. Nucleosynthesis: Origin of the Elements The Birth of the Solar System The present-day properties of the Solar System hold important clues to its formation history. Relevant Observations: • Orbits of the planets and asteroids. • Rotation of the planets and the Sun. • Composition of the planets, especially the strong distinction between Terrestrial, Jovian, and Icy planets. Clues from planetary motions: • Planets orbit in nearly the same plane. • Planet orbits are nearly circular. • Planets & Asteroids orbit in the same direction. • Rotation axes of the planets tends to align with the sense of their orbits, with exceptions. • Sun rotates in the same direction in the same sense. • Jovian moon systems mimic the Solar System. Clues from planet composition: Inner Planets & Asteroids: • Small rocky bodies • Few ices or volatiles Jovian Planets: • Deep Hydrogen & Helium atmospheres rich in volatiles. • Large ice & rock cores Outer solar system moons & icy bodies: • Small ice & rock mixtures with frozen volatiles. Formation of the Sun Stars form out of interstellar gas ...

• Afrikaans • العربية • Asturianu • Azərbaycanca • বাংলা • Català • Čeština • Deutsch • Español • Euskara • فارسی • Français • 한국어 • Hrvatski • Bahasa Indonesia • עברית • नेपाली • 日本語 • Norsk bokmål • Norsk nynorsk • Português • Română • Русский • සිංහල • Српски / srpski • Srpskohrvatski / српскохрватски • ไทย • Türkçe • Українська • Tiếng Việt • 中文 • v • t • e The nebular hypothesis is the most widely accepted model in the field of solar nebular disk model ( SNDM) or solar nebular model. According to the nebular theory, stars form in massive and dense clouds of The protoplanetary disk is an The formation of M Earth) it accelerates and proceeds in a runaway manner. History [ ] Main article: There is evidence that Exposition du systeme du monde. He envisioned that the Sun originally had an extended hot atmosphere throughout the volume of the Solar System. His theory featured a contracting and cooling protosolar cloud—the protosolar nebula. As this cooled and contracted, it flattened and spun more rapidly, throwing off (or shedding) a series of gaseous rings of material; and according to him, the planets condensed from this material. His model was similar to Kant's, except more detailed and on a smaller scale. A major critique came during the 19th century from different rotation between the inner and outer parts of a ring could not allow condensation of material. The perceived deficiencies of the Laplacian model stimulated scientists to find a replacement for it. During the ...

The Solar System that we live in consists of a medium-size star (the Sun) with eight planets orbiting it. The planets are of two different types. The four inner planets, those closest to the Sun, are Mercury, Venus, Earth, and Mars. They are smaller and composed mainly of metals and rocks. The four outer planets — Jupiter, Saturn, Uranus, and Neptune — are larger and composed mostly of gases. Let’s quickly review how our star came into being. Five billion years ago, a giant cloud floated in one of the spiral arms of the Milky Way galaxy. This cloud, called a nebula by astronomers, was made up of dust and gas, mostly hydrogen and helium, with a small percentage of heavier atoms. These heavier atoms had been formed earlier in the history of the Universe when other stars aged and died. This cloud/nebula began to contract, collapsing in on itself. The atoms, once separated, began to jostle each other, generating heat. In the rising heat, the atoms collided more frequently and more violently. Eventually, they reached a temperature at which the protons at the centers of the atoms began to fuse, in a process called nuclear fusion. As they did, a tiny bit of matter transformed into a whole lot of energy, and a star was born. In this way, our Sun came into being. Each planet began as microscopic grains of dust in the accretion disk. The atoms and molecules began to stick together, or accrete, into larger particles. By gentle collisions, some grains built up into balls and then into...

Human deep space exploration is presented with multiple challenges, such as the reliable, efficient and sustainable operation of life support systems. The production and recycling of oxygen, carbon dioxide (CO 2) and fuels are hereby key, as a resource resupply will not be possible. Photoelectrochemical (PEC) devices are investigated for the light-assisted production of hydrogen and carbon-based fuels from CO 2 within the green energy transition on Earth. Their monolithic design and the sole reliance on solar energy makes them attractive for applications in space. Here, we establish the framework to evaluate PEC device performances on Moon and Mars. We present a refined Martian solar irradiance spectrum and establish the thermodynamic and realistic efficiency limits of solar-driven lunar water-splitting and Martian carbon dioxide reduction (CO 2R) devices. Finally, we discuss the technological viability of PEC devices in space by assessing the performance combined with solar concentrator devices and explore their fabrication via in-situ resource utilization. Long-term space missions face similar challenges to the realisation of a green energy economy on Earth: solar energy systems are required to convert and store energy in the form of fuels, electricity and chemicals for day and night operation at high efficiency, stability and durability. At present, about 1.5 kW out of the 4.6 kW energy budget of the Environmental Control and Life Support System on the International Spa...

The growth of planetesimals from smaller solid particles that collided and stuck together At first, accretion probably arose from electrostatic attractions, but as planetesimals grew larger their gravity allowed them to accrete more efficiently (as long as they didn't suffer collisions with similar-size planetesimals)

The Solar System that we live in consists of a medium-size star (the Sun) with eight planets orbiting it. The planets are of two different types. The four inner planets, those closest to the Sun, are Mercury, Venus, Earth, and Mars. They are smaller and composed mainly of metals and rocks. The four outer planets — Jupiter, Saturn, Uranus, and Neptune — are larger and composed mostly of gases. Let’s quickly review how our star came into being. Five billion years ago, a giant cloud floated in one of the spiral arms of the Milky Way galaxy. This cloud, called a nebula by astronomers, was made up of dust and gas, mostly hydrogen and helium, with a small percentage of heavier atoms. These heavier atoms had been formed earlier in the history of the Universe when other stars aged and died. This cloud/nebula began to contract, collapsing in on itself. The atoms, once separated, began to jostle each other, generating heat. In the rising heat, the atoms collided more frequently and more violently. Eventually, they reached a temperature at which the protons at the centers of the atoms began to fuse, in a process called nuclear fusion. As they did, a tiny bit of matter transformed into a whole lot of energy, and a star was born. In this way, our Sun came into being. Each planet began as microscopic grains of dust in the accretion disk. The atoms and molecules began to stick together, or accrete, into larger particles. By gentle collisions, some grains built up into balls and then into...

• Afrikaans • العربية • Asturianu • Azərbaycanca • বাংলা • Català • Čeština • Deutsch • Español • Euskara • فارسی • Français • 한국어 • Hrvatski • Bahasa Indonesia • עברית • नेपाली • 日本語 • Norsk bokmål • Norsk nynorsk • Português • Română • Русский • සිංහල • Српски / srpski • Srpskohrvatski / српскохрватски • ไทย • Türkçe • Українська • Tiếng Việt • 中文 • v • t • e The nebular hypothesis is the most widely accepted model in the field of solar nebular disk model ( SNDM) or solar nebular model. According to the nebular theory, stars form in massive and dense clouds of The protoplanetary disk is an The formation of M Earth) it accelerates and proceeds in a runaway manner. History [ ] Main article: There is evidence that Exposition du systeme du monde. He envisioned that the Sun originally had an extended hot atmosphere throughout the volume of the Solar System. His theory featured a contracting and cooling protosolar cloud—the protosolar nebula. As this cooled and contracted, it flattened and spun more rapidly, throwing off (or shedding) a series of gaseous rings of material; and according to him, the planets condensed from this material. His model was similar to Kant's, except more detailed and on a smaller scale. A major critique came during the 19th century from different rotation between the inner and outer parts of a ring could not allow condensation of material. The perceived deficiencies of the Laplacian model stimulated scientists to find a replacement for it. During the ...

In studying our Solar System over the course of many centuries, astronomers learned a great deal about the types of planets that exist in our universe. This knowledge has since expanded thanks to the discovery of extrasolar planets, many of which are similar to what we have observed here at home. For example, while hundreds of gas giants of varying size have been detected (which are easier to detect because of their size), numerous planets have also been spotted that are similar to Earth – aka. “Earth-like”. These are what is known as terrestrial planets, a designation which says a lot about a planet how it came to be. Definition: Also known as a telluric or rocky planet, a terrestrial planet is a celestial body that is composed primarily of silicate rocks or metals and has a solid surface. This distinguishes them from gas giants, which are primarily composed of gases like hydrogen and helium, water, and some heavier elements in various states. Remove All Ads on Universe Today Join our Patreon for as little as $3! Get the ad-free experience for life The term terrestrial planet is derived from the Latin “Terra” (i.e. Earth). Terrestrial planets are therefore those that are “Earth-like”, meaning they are similar in structure and composition to planet Earth. Artist’s concept for the range of Earth-like extrasolar planets that have been discovered in recent years. Credit: NASA/JPL Composition and Characteristics: All terrestrial planets have approximately the same type of stru...