Our Solar System: Inner Planets

Showing posts with label Inner Planets. Show all posts

Sunday, 7 August 2022

Mars

Mars Facts

Equator circumference: 21,297km
Radius: 3,390km
Average distance from Sun: 228 million km
Surface temperature: -153°C to 20°C
Average orbital speed: 86,700km/h (24km/s)
Day length: 24.6 hours
Year length: 687 Earth days
Moons: 2
Planet type: terrestrial

How big is Mars?

Mars is around two times smaller than Earth. It has an equatorial circumference of about 21,000 kilometres, and a radius (the distance from the middle of its core to the surface) of around 3,400 kilometres.

It's thought that Mars's core is predominantly made up of iron, but also nickel and sulphur. The core is about half the size of the planet and may be entirely liquid, or have a solid iron centre and a liquid exterior.

Mars boasts the largest volcano in the solar system. Olympus Mons is a shield volcano around 25 kilometres in height and 624 kilometres in diameter - the largest volcano on Earth, Mauna Loa in Hawaii, is just over four kilometres in height and 120 kilometres wide.

The deepest canyon on the planet is Valles Marineris at 7 kilometres - Earth's Grand Canyon is only 1.8 kilometres deep. Valles Marineris was mostly formed by tectonic processes.

How far from the Sun is Mars?

Mars is the fourth planet from the Sun, orbiting at an average of 228 million kilometres away from the star. The planet moves at a speed of around 24 kilometres per second, making it slightly slower than Earth.

It has an elliptical orbit, meaning it is egg- or oval-shaped. This means that throughout its year, Mars's distance from the Sun ranges between around 206 million and 249 million kilometres.

What is Mars's atmosphere made of?

Mars's atmosphere is made up of around 96% carbon dioxide. It also contains small quantities of argon, nitrogen, oxygen and water vapour.

The atmosphere is very thin, but it is thought that in the past it was much thicker. The loss has been attributed to the solar winds, although there are other processes that can thin an atmosphere (such as the impacts of astronomical bodies).

Is there water on Mars?

Mars almost certainly had surface water in the past, interpreted from the evidence of canyons, dry lakebeds and river networks.

Although these features could only have been formed by liquid water, there is none left on the surface now due to the cold, thin atmosphere. But the planet has polar ice caps. If these melted, the planet would be covered by 20- to 30-metre-deep water.

Earth

Earth, our home, is the third planet from the sun. While scientists continue to hunt for clues of life beyond Earth, our home planet remains the only place in the universe where we've ever identified living organisms.

Earth is the fifth-largest planet in the solar system. It's smaller than the four gas giants Jupiter, Saturn, Uranus and Neptune but larger than the three other rocky planets,Mercury, Mars and Venus.

Earth has a diameter of roughly 8,000 miles (13,000 kilometers) and is mostly round because gravity generally pulls matter into a ball. But the spin of our home planet causes it to be squashed at its poles and swollen at the equator, making the true shape of the Earth an "oblate spheroidOur planet is unique for many reasons, but its available water and oxygen are two defining features. Water covers roughly 71% of Earth's surface, with most of that water located in our planet's oceans. About a fifth of Earth's atmosphere consists of oxygen, produced by plants.

Earth Internal Structure

Earth's core is about 4,400 miles (7,100 km) wide, slightly larger than half the Earth's diameter and about the same size as Mars. The outermost 1,400 miles (2,250 km) of the core are liquid, while the inner core is solid. That solid core is about four-fifths as big as Earth's moon, at some 1,600 miles (2,600 km) in diameter. The core is responsible for the planet's magnetic field, which helps to deflect harmful charged particles shot from the sun.

Above the core is Earth's mantle, which is about 1,800 miles (2,900 km) thick. The mantle is not completely stiff but can flow slowly. Earth's crust floats on the mantle much as a piece of wood floats on water. The slow motion of rock in the mantle shuffles continents around and causes earthquakes, volcanoes and the formation of mountain ranges.

PLANET EARTH'S ORBIT AROUND THE SUN

While Earth orbits the sun, the planet is simultaneously spinning around an imaginary line called an axis that runs through the core, from the North Pole to the South Pole. It takes Earth 23.934 hours to complete a rotation on its axis and 365.26 days to complete an orbit around the sun our days and years on Earth are defined by these gyrations.
Earth's axis of rotation is tilted in relation to the ecliptic plane, an imaginary surface through the planet's orbit around the sun. This means the Northern and Southern hemispheres will sometimes point toward or away from the sun depending on the time of year, and this changes the amount of light the hemispheres receive, resulting in the changing seasons.
Earth happens to orbit the sun within the so-called "Goldilocks zone," where temperatures are just right to maintain liquid water on our planet's surface. Earth's orbit is not a perfect circle, but rather a slightly oval-shaped ellipse, similar to the orbits of all the other planets in our solar system. Our planet is a bit closer to the sun in early January and farther away in July, although this proximity has a much smaller effect on the temperatures we experience on the planet's surface than does the tilt of Earth's axis.
Statistics about Earth's orbit, according to NASA:
Average distance from the sun : 92,956,050 miles (149,598,262 km)
Perihelion (closest approach to the sun): 91,402,640 miles (147,098,291 km)
Aphelion (farthest distance from the sun): 94,509,460 miles (152,098,233 km)
Length of solar day (single rotation on its axis): 23.934 hours
Length of year (single revolution around the sun): 365.26 days
Equatorial inclination to orbit: 23.4393 degrees

Additional Resources:-
https://en.wikipedia.org/wiki/Earth
https://books.google.lk/books?id=WVb6Uu9aluYC&dq=earth+planet&hl=en&sa=X&redir_esc=y
https://www.planetary.org/worlds/earth

Earth's core is about 4,400 miles (7,100 km) wide, slightly larger than half the Earth's diameter and about the same size as Mars.
The outermost 1,400 miles (2,250 km) of the core are liquid, while the inner core is solid. That solid core is about four-fifths as big as Earth's moon, at some 1,600 miles (2,600 km) in diameter. The core is responsible for the planet's magnetic field, which helps to deflect harmful

charged particles shot from the sun.

Above the core is Earth's mantle, which is about 1,800 miles (2,900 km) thick. The mantle is not completely stiff but can flow slowly. Earth's crust floats on the mantle much as a piece of wood floats on water. The slow motion of rock in the mantle shuffles continents around and causes earthquakes, volcanoes and the formation of mountain ranges.
Related: Earth's layers: Exploring our planet inside and out
Above the mantle, Earth has two kinds of crust. The dry land of the continents consists mostly of granite and other light silicate minerals, while the ocean floors are made up mostly of a dark, dense volcanic rock called basalt. Continental crust averages some 25 miles (40 km) thick, although it can be thinner or thicker in some areas. Oceanic crust is usually only about 5 miles (8 km) thick. Water fills in low areas of the basalt crust to form the world's oceans.
Earth gets warmer toward its core. At the bottom of the continental crust, temperatures reach about 1,800 degrees Fahrenheit (1,000 degrees Celsius), increasing about 3 degrees F per mile (1 degree C per km) below the crust. Geologists think the temperature of Earth's outer core is about 6,700 to 7,800 degrees F (3,700 to 4,300 degrees C) and that the inner core may reach 12,600 degrees F (7,000 degrees C) — hotter than the surface of the sun.

Venus

Venus is a hot and hellish world and the second planet from the sun. The Earth-size planet could be considered our twin if not for its thick, toxic atmosphere and surface temperatures that are hot enough to melt lead.

Despite such extremes, researchers have long wondered if organisms could exist in the upper cloud layers of Venus, where more clement conditions can be found. Controversial data suggest that Earth's sister world in the solar system may not be so different from life-bearing Earth after all.

Venus' modern name comes from the ancient Roman goddess of love and beauty, according to NASA(opens in new tab). After the sun and the moon, Venus is the third-brightest object in Earth's sky, meaning people have known about it since time immemorial.

The ancient Greeks named Venus after their own love goddess Aphrodite, while the ancient Egyptians named the planet for the goddess Isis,according to the European Southern Observatory . Other names for Venus include Astarte (Phoenician), Fria (Saxon), Ishtar (Sumerian) and Jīnxīng (Great White One in Chinese). The Maya considered Venus a god of war and kept careful records of its position in the sky.

What Is Venus Made Of ?

Like Earth, Venus is a rocky planet. With a diameter of 7,520 miles (12,100 kilometers), according to NASA

, Venus is only a little smaller than our planet, with a mass about 80% of Earth's, according to Live Science's sister site Space.com.

The interior composition of Venus is quite similar to that of Earth; both planets have an iron core surrounded by a hot-rock mantle and a thin outer crust,according to NASA

. Venus' surface is covered in a range of geological structures, such as mountains, valleys and volcanoes. It even has continent-like features, including an Australia-size rocky highland area called Ishtar Terra near its north pole, and an even larger, South-America-size region called Aphrodite Terra stretching across its equator.

Venus has very few visible impact craters, suggesting that its surface is relatively young. Mounting evidence suggests that our nearest planetary neighbor is still geologically active, with a partially molten mantle, moving tectonic plates and erupting volcanoes.

The atmosphere of Venus is mainly carbon dioxide and contains thick permanent clouds composed of sulfuric acid, according to NASA. This creates an intense surface pressure more than 90 times that of the Earth and surface temperatures near 900 degrees Fahrenheit (482 degrees Celsius). Water can't exist in liquid form on the surface, and very little water vapor exists in Venus' atmosphere.

How Far Is Venus From The Sun

Venus is 67 million miles (108 million km) from the sun on average,according to NASA , which is roughly 70% the distance between Earth and the sun. Venus is the nearest planet to our world, coming within roughly 38 million miles (61 million km) at its closest approach.

The length of a year on Venus is 225 Earth days, but because our sister world spins extremely slowly on its axis, its day length is longer than its year — 243 Earth days, according to NASA. The sun rises in the west and sets in the east on Venus because the planet spins in the opposite direction to ours, though nobody knows why.

Additional Resources:-

https://en.wikipedia.org/wiki/Venus

https://www.rmg.co.uk/stories/topics/interesting-facts-about-venus

Mercury

The smallest planet in our solar system and nearest to the Sun, Mercury is only slightly larger than Earth's Moon. From the surface of Mercury, the Sun would appear more than three times as large as it does when viewed from Earth, and the sunlight would be as much as seven times brighter.

Mercury's surface temperatures are both extremely hot and cold. Because the planet is so close to the Sun, day temperatures can reach highs of 800°F (430°C). Without an atmosphere to retain that heat at night, temperatures can dip as low as -290°F (-180°C).

Despite its proximity to the Sun, Mercury is not the hottest planet in our solar system – that title belongs to nearby Venus, thanks to its dense atmosphere. But Mercury is the fastest planet, zipping around the Sun every 88 Earth days.

Potential for Life

Mercury's environment is not conducive to life as we know it. The temperatures and solar radiation that characterize this planet are most likely too extreme for organisms to adapt to.

Size and Distance

With a radius of 1,516 miles (2,440 kilometers), Mercury is a little more than 1/3 the width of Earth. If Earth were the size of a nickel, Mercury would be about as big as a blueberry.

From an average distance of 36 million miles (58 million kilometers), Mercury is 0.4 astronomical units away from the Sun. One astronomical unit (abbreviated as AU), is the distance from the Sun to Earth. From this distance, it takes sunlight 3.2 minutes to travel from the Sun to Mercury.

Mercury Orbit and Rotation

Mercury's highly eccentric, egg-shaped orbit takes the planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million kilometers) from the Sun. It speeds around the Sun every 88 days, traveling through space at nearly 29 miles (47 kilometers) per second, faster than any other planet.

Mercury spins slowly on its axis and completes one rotation every 59 Earth days. But when Mercury is moving fastest in its elliptical orbit around the Sun (and it is closest to the Sun), each rotation is not accompanied by sunrise and sunset like it is on most other planets. The morning Sun appears to rise briefly, set, and rise again from some parts of the planet's surface. The same thing happens in reverse at sunset for other parts of the surface. One Mercury solar day (one full day-night cycle) equals 176 Earth days – just over two years on Mercury.

Mercury's axis of rotation is tilted just 2 degrees with respect to the plane of its orbit around the Sun. That means it spins nearly perfectly upright and so does not experience seasons as many other planets do.