A galaxy is a gravitationally bound system of stars and other celestial bodies....
QUIZ WHIZ
Answers
1. B
A galaxy is a gravitationally bound system of stars and other celestial bodies.
Our solar system is part of the Milky Way Galaxy (which takes its name from the Milky Way band of light that the galaxy forms in the night sky) and is located in the large spiral arm about two-thirds of the way from the galactic centre.
The Andromeda Galaxy is the nearest major galaxy to the Milky Way.
Ursa Major and Ursa Minor are constellations (groups of stars) in the northern sky.
2. C
A dwarf planet is a planet-like body that is in direct orbit of a star, has enough gravity to compress itself into a spheroid, but has not cleared the neighbourhood of other material around its orbit (that is, it hasn’t become gravitationally dominant and is under the influence of another body).
In 2006, lovely little Pluto (discovered in 1930) was downgraded from a planet to a dwarf planet (Thanks so much, Mike Brown! :@ #PlutoWillAlwaysBeAPlanetToMe). Four other bodies have since been recognized as dwarf planets - Ceres (discovered in 1801) and Eris (2004) which joined the list in 2006, and Haumea (2005) and Makemake (2005) which were accepted in 2008 - bringing the total number to five.
Additionally, there are six other bodies that have been proposed to be classified as dwarf planets.
The actual number of dwarf planets in our solar system, however, is much larger. It is estimated that there may be as many as 200 in the outer solar system and possibly thousands more in the region beyond.
3. A
Neptune is the farthest planet from the Sun in the solar system. It is the fourth largest planet by diameter and the third most massive planet, nearly 17 times the mass of Earth.
(Although obviously Pluto is the farthest “planet” from the Sun, and, as we’ve already established, it is clearly still a planet in my head, so Pluto is also an acceptable answer. It is the wrong answer, but it is acceptable.)
4. D
Jupiter - the largest planet in our solar system with a mass of two and a half times that of all the other planets combined - has 79 known natural satellites (10 of which were just confirmed last month). Other tiny undiscovered moons probably exist and may not have been detected yet.
5. A
Uranus gets its name from the primal Greek god Uranus whose abode was the sky. German-born British astronomer William Herschel, who discovered the planet in 1781, named it Georgium Sidus (Georgian Star) after monarch George III. The name Uranus was officially accepted in the mid-19th century, as suggested by German astronomer Johann Bode to complement the other planets which are named after Roman gods.
6. C
Venus has the longest rotation period of any planet in the Solar System. A day on Venus lasts for 243 Earth days! That’s 5,832 hours!
A Venusian day lasts longer than a Venusian year, as the planet takes around 224.7 Earth days to complete an orbit around the Sun.
Fun fact: Venus is the nearest planet to Earth when it is in the middle of the Sun and Earth, but there are times when Mars is Earth’s closest neighbour instead.
7. D
The orbital period of Pluto - THE NINTH PLANET IN OUR SOLAR SYSTEM (Shut it, Neil deGrasse Tyson!) - is about 90,560 days, which means Pluto takes around 248 Earth years to complete one revolution!
8. B
You’d think Mercury would be the hottest planet since it is the closest to the Sun, but that title actually goes to Venus, which has the hottest surface temperature, even though Venus is nearly twice Mercury’s distance from the Sun. The atmosphere consists mostly of carbon dioxide while generates a strong greenhouse effect, creating surface temperatures of 462 °C.
9. B
Saturn’s rings are made almost entirely of ice, with trace components of dust and rock particles. The planet has four main groups of rings as well as three narrower groups.
10. C
The equatorial circumference of the Moon is approximately 10,917 km, while the Earth’s circumference is around 40,030 km, which makes the Earth approximately four times bigger than the Moon.
11. D
The main elements in the solar system are hydrogen (which is the most abundant) and helium, primarily because of the composition of the Sun which accounts for the bulk of the mass of the solar system.
12. A
NASA’s space probe Voyager 1 is thought to have left the heliosphere (region of space dominated by our Sun) in 2012, making the spacecraft the first humanmade object to reach interstellar space. Launched in September 1977, 16 days after its twin Voyager 2 (which is expected to reach interstellar space in either late 2019 or early 2020), Voyager 1 is part of a program to study the outer solar system and has been operational for more than 40 years. It still communicates with Earth; its signals take over 19 hours to reach our planet.
- S.A
