Astronomy: "We All Shine On" Trivia Quiz

Answer: Fusion of hydrogen nuclei into helium

The sun, at 1 392 685 km in diameter and 1.99x10E27 metric tonnes, is almost 110 times the size of Earth and 330 000 times as heavy as Earth. Through fusion of hydrogen nuclei, 6 200 000 tonnes of hydrogen are fused per second in its core. The sun contains around 74-75% hydrogen and 23-24% helium but just over 2% in weight is attributed to oxygen, carbon, iron and neon.

Answer: -153C to 20C

The seasons are twice as long as Earth seasons simply because the orbit of Mars is about twice the size of that of Earth. Mars has a wide temperature variance for several reasons: its thin atmosphere means heat from the sun is difficult to store, it has low (compared with Earth) atmospheric pressure, its distance from the sun means it receives only approximately 40% of the amount of sunlight that Earth does, and there is low thermal heat retention in the Martian soil and rock at the surface.

Answer: Two moons, Ganymede and Titan, are larger

Ganymede, Jupiter's largest moon, has a radius of approximately 2630km. Titan, the second biggest moon, belongs to Saturn and has a radius of 2580km. Both these moons have radii 1.4 times the radius of (Earth's) Moon and 0.4 times Earth's radius. Mercury's radius is 2440km.

Mercury has an orbital period (year) of 88 Earth days. It rotates on its axis once every two of its years. Therefore one Mercury day equals two of its years. Weird.

Answer: Large, dark areas on the moon's surface

'Maria' is the plural of 'mare', meaning 'sea'. Ancient astronomers thought that the dark areas of the moon were seas of water; however, they are actually large flat areas of rock and sand. When man landed on the moon in 1969, they touched down on Mare Tranquillitatis, better known as the Sea of Tranquility.

Answer: Phobos and Deimos

Phobos (Fear) and Deimos (Terror) were the sons of Ares, the God of War; Mars was his Roman equivalent. Phobos and Deimos are therefore the sons of Mars (Geddit!)

Answer: 20 metres

The rings mainly consist of small ice particles, and their circumference extends more than 4 million kilometres around the planet. The first person to identify them as rings was Galileo, in 1610.

Answer: About 40% of Earth's radius

Ganymede is one of four Galilean moons of Jupiter. These four moons of Jupiter were discovered by Galileo in 1610. The three inner moons, Ganymede, Europa and Io, all have an effect on each other's orbit. (The fourth is Callisto.) All four are named after lovers of Zeus.

Answer: Roman name

Uranus, the seventh planet from the sun, is the third biggest planet in the solar system. Little is known about its surface characteristics as it has a dense, complex atmosphere made up of hydrogen, helium, methane, ammonia and water ice.

Ouranos was the Greek god representing the sky, and Uranus is the Latinised equivalent of Ouranos. (The equivalent Roman god is Caelus.)

Answer: Cannot be seen

Even through a telescope, Neptune is hard to see. Voyager 2 had a close encounter with the planet and a couple of its moons in 1989.

Answer: Both are classified as dwarf planets

The IAU ( International Astronomical Union) defines a dwarf planet as "... a celestial body that
(a) is in orbit around the Sun,
(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
(c) has not cleared the neighbourhood around its orbit, and
(d) is not a satellite."

Ceres, one of the largest objects in the Asteroid Belt, was promoted to dwarf planet, and Pluto was downgraded to the same designation in 2006.