Solar System - Random Facts Trivia Quiz

Answer: 4.6 billion years ago; 5 billion years

The Sun as we know it today is a yellow G2 star, with a surface temperature of 6000 K. It has been active for about 4.5 billion years. This figure was determined by dating other radioactive objects known to have approximately the same age. So far, the Sun has consumed about half of the hydrogen atoms in its core.

In spite of using 5 million tones of hydrogen in fusion reactions every second, there is still enough material left to power it for another 5 billion years. However this doesn't mean that the Sun will stay the same during this period...

It will get bigger and hotter until the nuclear reactions in its core will stop. Then, it will become a giant red star (with a surface temperature of 3000 K), reaching the orbit of Mercury, which will vanish.

The Sun will gradually cool down and eventually 'die', after having burned out Venus and unfortunately, Earth.

Answer: the shrinking of the planet's surface

As Mercury's interior cooled and contracted, the surface of the planet shrank and wrinkled. The radius itself decreased about 1 km. This phenomenon led to the forming of the huge escarpments, thousands of km long and several km high.

Answer: carbon dioxide

Carbon dioxide makes up 96% of Venus' atmosphere, while the rest consists of nitrogen (3.5%), sulfur dioxide (0.15%) and other gases.
This heavy atmosphere, combined with the thick layer of sulfuric acid clouds, traps the heat, producing the runaway greenhouse effect. This is the reason why the surface of the planet records a uniform temperature of 750K, hotter even than that of Mercury's.

Answer: Greek scholar Eratosthenes

Eratosthenes lived in Alexandria in the 3rd century BC. His accurate measurement relied on some well-inspired observations and basic geometry. He noticed that at the midsummer's noon, at a particular deep well in Syene (up the Nile), the Sun appeared directly overhead.

At the same time, in Alexandria, the Sun was off from the vertical position by an angle of 7 degrees (vertical objects were casting shadows). Assuming that the Sun's rays felt parallel on the surface of the Earth, Eratosthenes came up with a remarkably accurate result: 25,000 miles for the circumference. Eratosthenes also measured the distances from the Earth to the Sun and to the Moon, as well as the tilt of the Earth's axis (all of these with an astonishing precision).

Answer: both poles have permanent ice caps

The major differences between the northern and the southern hemisphere (more precisely the upper third and the southern two thirds) still puzzle scientists, some of them suspecting a very large impact as the main reason. Separated by an abrupt elevation change, the hemispheres are striking with their contrasting features.

While the South is heavily 'bombarded', bearing the mark of the ancient collisions (for example the "Hellas Planita" crater has over 6 km deep and 2000 km in diameter), the North is covered mainly by low plains and volcanoes.

The 'Mars Global Surveyor' (an orbiter launched in 1996) indicates that the crust is 35 km thick in the Northern Hemisphere and around 80 km in the south. Although both poles have ice caps, there are still differences about them: the North pole is thought to be water ice, while the South pole is more likely to contain CO2 ice.

As for the 24000 m, "Olympus Mons" is one of the tallest mountains in the Solar system.

Answer: it's far smaller than a star and has a solid inner core

Although its atmosphere closely resembles the composition of a star there are several major reasons for which Jupiter doesn't fit in the star category. First of all it should be 80 times more massive in order to reach the dimensions of even the smallest star.

Then, Jupiter developed from an original rocky kernel, which was then surrounded by gases. And in spite of this core being extremely hot - about 20000 K (Jupiter produces more energy than it receives from the Sun)- it's still insufficient to ignite nuclear reactions, which 'power' the stars.

Answer: Cassini-Huygens

Launched in October 1997, Cassini was designed for a four year study of Saturn, as well as its moons. The mission was based on a joint US/EU project: NASA built the Cassini spacecraft while the European Space Agency built the Huygens probe. The probe landed on Titan in January 2005.

Update: although intended to last only four years, the mission only ended in 2017 with a planned burn-up of the spacecraft in Saturn's atmosphere.

Answer: 0

In spite of having 27 satellites, none of Uranus' moons is larger than our moon. In fact, even the largest (Titania) is just about half that size. Besides Titania, there are four more relatively large moons, each of them showing interesting features. Miranda's shattered surface, with its distinctive V-shaped groove, bears the scars of the many past collisions. Ariel is the youngest and brightest of Uranus' moons contrasting with the dark, heavy bombarded Umbriel. Oberon, like Titania, was discovered by William Herschel (the astronomer who discovered Uranus itself) and is covered by ice and numerous craters.

Answer: a pair of strong binoculars

Surprisingly, you can see 99.99% of the mass of our Solar System with the unaided eye. For Neptune however, you would still need a simple pair of binoculars. Neptune's visual magnitude (the maximum brightness that the object attains when it is closest to Earth) is +8.3, whereas, by comparison, the Sun's, the Moon's and Saturn's are -27, -13 and +0.7 respectively.

The binoculars would allow you to also see Ganymede (+4.6), Io (+5.0), Europa (+5.3), Uranus (+5.5), Callisto (+5.6), Titan (+8.3) and occasionally asteroids and comets. Never thought this could be so easy did you? Be warned though: don't stare at the Sun with the binoculars, because it could burn a hole in your retina in just a fraction of a second.

Answer: by observing the transits of Pluto over its satellite Charon and vice versa

Charon was discovered at the Naval Observatory in 1978, 48 years after the discovery of Pluto. The two icy bodies rotate and revolve synchronously, keeping the same face towards each other.
Thank you for playing and I hope you'll get a clear sky tonight...