Uranus is the first planet, which is discovered by telescope by astronomer William Herschel in 1781.
It is the seventh planet from the sun at a distance of about 1.8 billion miles (19.8 AU). It has the 3rd largest planetary radius and the 4th largest planetary mass in the solar system.
Uranus is an ice giant. It is made of mostly dense fluid of ice materials like water, methane, and ammonia, which lie above a small rocky core. It has an atmosphere made mostly of molecular hydrogen and atomic helium, with a small amount of methane.
Day and Year
Uranus takes 84 earth years to complete an orbit of the sun and 17 hours to rotate own axis.
It is known as the “sideways planet” because it rotates on its side. This unique sideways rotation makes for weird seasons.
The planet North Pole experience 21 years of night time in winter, 21 years of day time in summer, and 42 years of day and night in the spring.
Surface and Structure
This ice giant is a swirling fluid. It has no solid surface like the Earth and Mars. When someone tries to land on Uranus, they will found no surface for landing or even they wouldn’t fly through unscathed either. The extreme pressure and temperature deep inside the planet crush, melt and vaporize the spacecraft try to fly into the planet. Its surface gravity is 8.69 m/s2.
The structure of this palnet consist of three layer. In the center, a Core exits. The rocky core of Uranus, about 0.55 times massive than earth is likely composed of Iron, Nickel, and silicate. The pressure at the center is about 8 Mbar and the temperature may be about 5,000 k. Above the core; A Mantle, Hot, dense fluid of Icy material (Water, ammonia, and Methane) exits. This region is 13.4 times massive than the earth. Its upper atmosphere is relatively insubstantial, weighing about 0.5 Earth masses and extending for the last 20% of Uranus’s radius. The scientist also believes that the top of the mantle may be an ocean of liquid carbon with floating solid ‘diamonds’.
The diameter of Uranus is slightly larger than Neptune and roughly four times the Earth’s. A resulting density of 1.27 g/cm3 makes Uranus the second least dense planet, after Saturn.
Size and Distance
The mean radius of Uranus is 25,362 km. it is 4 times wider than earth and 14.536 times massive than earth with a mass of 8.688×1025 kg.
It occupied 6.833×1023 km3 of volume that could fit 63 piles of earth inside it.
From an average distance of 1.8 billion miles (2.9 billion km), Uranus is 19.8 astronomical units away from the Sun. From this distance, it takes Sunlight 2 hours 4 minutes to travel from the Sun to this planet.
Uranus’s atmosphere is made up mostly of hydrogen, helium, and a trace amount of methane. it’s at- mospheric methane absorbs the red light, which gives a signature blue color to Uranus.
The atmosphere of this planet can be divided into three layers. The first layer; troposphere lies between altitudes of 0 to 350 km with pressures from 0.1 to 100 bar. Second layer; the Stratosphere, spanning between altitudes 50 and 4,000 km and pressures of between 0.1 and 10−10 bar. And last third layer; the Thermosphere extending from 4,000 km to as high as 50,000 km from the surface.
Orbital and escape velocity
Its average orbital speed is 6.80 km/s i.e. 0.2287 times earth’s average orbital speed and escape velocity is 21.3 km/s (1.90 times earth’s escape velocity).
Uranus’s magnetic field is tilted 59 degrees relative to the rotational axis and offset 0.33 radii from the planet’s physical center.
The magneto- sphere of Uranus is highly asymmetry. Magnetic field strength on the surface in the southern hemisphere can be as low as 0.1 gauss whereas in the northern hemisphere it can be as high as 1.1 gauss.
It has relatively well- developed aurorae, which are seen as bright arcs around both magnetic poles. But unlike the Jupiter and Saturn, its Auroras are not in line with the poles.
Uranus has 27 known moons. Out of 27, five are the main moons; Marinda, Ariel, Umbriel, Titania, and Oberon. The satellite system of Uranus is the least massive among those of the giant planets. The combined mass of the five major satellites would be less than half that of Triton (largest moon of Neptune) alone. Titania is the largest moon of Uranus and eighth largest moon in the solar system. Its radius is 790 km or less than half of the earth’s moon.
Moon of Uranus composed of roughly 50% ice and 50% rock.
Uranus has 13 known rings. The inner rings are narrow and dark but the outer rings are brightly colored.
In the order of increasing distance from the planet, the rings are Zeta, 6, 5, 4, Alpha, Beta, Eta, Gamma, Delta, Lambda, Epsilon, Nu, and Mu. They can be divided into three groups: nine narrow main rings (6, 5, 4, Alpha, Beta, Eta, Gamma, Delta, and Epsilon), two dusty rings (Zeta and Lambda), and two outer rings (Nu and Mu). Their radii range from about 38,000 km for the Zeta ring to about 98,000 km for the Mu ring.
Uranus does not support life. The temperature, pressure, and materials of the planet too extreme and volatile to adopt life.
Voyager 2 is the only and first spacecraft that has visited Uranus. spacecraft takes the closest approach to the planet on 24 January 1986. It made the closest approached 81,500 km (50,600 mi) from the top cloud of Uranus before keep up its journey to Neptune.
The spacecraft studied the structure and chemical composition of Uranus’s atmosphere, including its unique weather, caused by its axial tilt of 97.77°. It also discovered ten new moons and two more rings.
In Greek religion, Uranus was the god of sky or heaven, but in ancient Greek literature, Uranus was the son and husband of Gaia the primordial mother earth. In the Hindu religion, Uranus is known as Varuna, the God of Sea and rain. Varuna is the son of Kashyapa (one of the seven ancient sages). In Hindu Puranas Varuna is the god of oceans, his vehicle is a Makara (crocodile) and his weapon is a Pasha (noose, rope loop).
Quick Discover :
Distance from the sun:
19.8 Astronomical unit
Average orbital speed:
Equatorial rotational velocity:
84 Earth Years
Potential for Life:
Image credit :
Image5: By ESA/Hubble, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=76497352