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Universe at a glance ......


HomeWorldgk⇒Universe at a Glance for GK

Sun
• The Sun is a star that is in the center of the Solar System.

• The Sun is recognized as having the largest mass in our Solar System.

• It has a diameter of about 1,392,684 km, about 109 times that of Earth.

• The sun is the closest star to Earth, at a mean distance from our planet of 149.60 million km.Sun

• Sun fuses 620 million metric tons of hydrogen each second.

• At the core, the temperature is about 27 million degrees Fahrenheit (15 million degrees Celsius).

• In February 1974, Skylab was the first manned spacecraft to study the Sun.

• Solar flares occur when magnetic fields of the Sun come together and cause huge explosions on the Sun’s surface.

• Solar flares produce bursts of electromagnetic radiation, x-rays, ultraviolet radiation, visible light, and radio waves.
 
Mercury
• Mercury is the closest and second smallest in the Solar System.Mercury

• Mercury is the second densest planet after Earth.

• The only visit to Mercury was a flyby made by the Mariner 10 spacecraft in 1974.

• Mercury speeds around the sun every 88 days, traveling through space at nearly 50 km (31 miles) per second.

• Galileo first observed Mercury during the 17th century.



 
Venus
• Venus is the second closest and sixth largest planet in the Solar System.

• The orbital speed of Venus is 35 km per second.Venus

• Venus is the hottest planet in the Solar System.

• Venus appears to be the brightest planet in the sky.

• It takes 244.7 days for Venus to rotate on its axis.

• The first robotic space probe mission to Venus, and the first to any planet, began on 12 February 1961, with the launch of the Venera 1 probe.
 
Earth
• Earth formed approximately 4.54 billion years ago, and life appeared on its surface within one billion years.

• The Earth is the densest planet in the Solar System. Earth

• Earth is the fifth largest planet in the Solar System.

• The Diameter of the Earth is 12,756 km (7,926 miles).

• The earth’s orbital speed is 29.8 km per second.

• Earth atmosphere consists of 78 percent nitrogen, 21 percent oxygen and 1 percent other ingredients.

• Earth rotates about its own axis 366.26 times, creating 365.26 solar days.
 
Moon
• The Moon is Earth’s lone natural satellite.

• In 1610, Galileo Galilei is the first to use a telescope to make scientific observations of the Moon.Moon

• The Moon is the fifth largest satellite in our Solar System.

• The Moon’s diameter is 2160 miles (3476 km).

• Average distance between the Earth and the Moon is about 239,000 miles. Actual distance varies from 221,457 to 252,712 miles.

• The Moon’s gravity is 1/6 that of Earth.

• The Moon does not have an atmosphere; there is no wind on the Moon.

• Apollo 11 was the American space mission to first reach and land on the moon.

• The first human landing on the Moon was on 20 July 1969.



• The Moon orbits around the Earth every 29 days.
 
Mars
• Mars is the fourth planet from the Sun and the second smallest planet in the Solar System.

• Iron oxide prevalent on its surface gives it a reddish appearance, often described as “ Red Planet”.Mars

• A Mars year is equal to 686.98 Earth Days.

• A day in Mars is equal to 24.6 Earth Hours.

• Like Earth, Mars experiences seasons because of the tilt of its rotational axis.

• Asaph Hall discovered both of Mars’ moons, Phobos and Deimos, in August 1877.

• Mariner 4 – first successful flyby mission to Mars. Launched on November 28, 1964 and arrived at Mars on July 14, 1965.

• Viking 1 – Successful orbit and landing on surface of Mars. Launched August 20, 1975 and arrived at Mars July 20, 1976.
 
Jupitar
• Jupiter, the largest planet in our solar system, is 318 times larger than Earth.Jupitar

• The orbital speed of Jupiter is 13.1 km/sec.

• A year on Jupiter is equal to 11.9 Earth Years.

• Jupiter has 67 natural satellites.[105] Of these, 51 are less than 10 kilometres in diameter and have only been discovered since 1975.

• Galileo Galilei had discovered Jupiter's four largest moons, now called Io, Europa, Ganymede, and Callisto. These four moons are known today as the Galilean satellites.

• In 1610, Galileo Galilei makes the first detailed observations of Jupiter.

• Jupiter's moon Ganymede is the biggest satellite in solar system.

• Jupiter has rings, the third planet discovered to have a ring system in our Solar System.

• Jupiter’s rings are identified as: Halo ring, Main ring, Amalthea gossamer ring, and Thebe gossamer ring.

• Jupiter’s rings were discovered by Voyager 1 in 1979.
 
Saturn
• Saturn is the sixth planet from the Sun and the second largest.Saturn

• Saturn has 62 known moons, fifty-three have been named. Most of them are small in size.

• Names of some of Saturn’s moons: the largest is Titan, discovered in 1655; Tethys, Dione, Rhea, & Iapetus, discovered from 1671 to 1672; Mimas & Enceladus, discovered in 1789; and Hyperion, discovered in 1848.

• A year on Saturn is equal to 29.5 Earth Years.

• Pioneer 11 is the first spacecraft to reach Saturn, in 1979.

• Saturn has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust.
 
Uranus
• The orbital speed of Uranus is 6.6 km/sec.Uranus

• Uranus takes 84 Earth years to complete one orbit.

• Uranus is the third largest planet in the Solar System.

• Voyager 2, the only spacecraft to visit Uranus.

• A day on Uranus is equal to a little more than 17 hours on Earth.

• Uranus has 27 known moons, named for characters from the works of William Shakespeare or Alexander Pope.

• Uranus was discovered by Sir William Herschel in 1781.
 
Neptune
• Neptune is the fourth largest planet and coolest planet in the Solar System.

• Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky.

• Neptune was discovered by Urbain Le Verrier, John Couch Adams, and Johann Galle on September 23, 1846.

• The only spacecraft ever to visit Neptune was Voyager 2 in 1989.Neptune

• The magnetic field of Neptune is about 27 times more powerful than that of Earth.

• One Neptune year is equal to 164.83 Earth Years.

• Neptune has six known rings.

• In 2011, Neptune completes its first 165-year orbit of the sun since its discovery in 1846.

• Neptune has 13 moons, the largest of which is named Triton. The other moons are: Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, Nereid, Halimede, Sao, Laomedeia, Neso, and Psamathe.
 
Pluto
• Pluto is the smallest planet in the Solar System, now consider as dwarf planet.Pluto

• Pluto is colder than Neptune.

• Pluto’s journey around the Sun takes 248 Earth years.

• Pluto is the second most contrast body in the Solar System.

• Pluto has not yet been visited by a spacecraft.

• Pluto has a satellite, Charon, which was discovered (in 1978). The distance between them is 19,640 km (12,200 miles).The other 3 are Nix, Hydra, and newly discovered S/2011 P 1 on July of 2011.

• Pluto rotation (a Pluto day) takes 6.4 Earth days, meaning that it has the second slowest rotation in the Solar System after Venus.

• Pluto was discovered by Tombaugh in 1930.