FREE! Click here to Join FunTrivia. Thousands of games, quizzes, and lots more!
Quiz about Fear and Dread
Quiz about Fear and Dread

Fear and Dread Trivia Quiz


The Red Planet has two moons: Phobos (fear) and Deimos (dread). What do you know of these companions to the god of war?

A multiple-choice quiz by reedy. Estimated time: 4 mins.
  1. Home
  2. »
  3. Quizzes
  4. »
  5. Science Trivia
  6. »
  7. Our Solar System
  8. »
  9. Moons

Author
reedy
Time
4 mins
Type
Multiple Choice
Quiz #
370,706
Updated
Dec 03 21
# Qns
10
Difficulty
Average
Avg Score
7 / 10
Plays
479
Last 3 plays: Guest 24 (9/10), slay01 (10/10), PurpleComet (7/10).
- -
Question 1 of 10
1. The two natural satellites of Mars were discovered by an American astronomer in August of 1877. Who was he? Hint


Question 2 of 10
2. The first of Mars' moons to be discovered was its outer moon, Deimos.


Question 3 of 10
3. Deimos is an small, irregularly-shaped, moon with an orbital period nearly four times that of its brother Phobos. How long does it take for Deimos to orbit Mars? Hint


Question 4 of 10
4. There are two craters on the surface of Deimos named for authors who wrote about the existence of two Martian moons in their works (prior to their actual discovery). Who were they? Hint


Question 5 of 10
5. Just how small is Deimos? Its widest dimensions are 15 by 12.2 by 11 km, it has a surface area of 495.15 square km, and a volume of approximately how many cubic kilometres? Hint


Question 6 of 10
6. Phobos, the inner of the two moons, has a quick orbital period, rising and setting twice during the Martian day (taking 4.25 hours to cross the sky, beginning again 11 hours later). Unlike Deimos, Phobos rises in the west and sets in the east.


Question 7 of 10
7. The Phobian surface is more pockmarked than that of Deimos. The most prominent feature is a large crater named Stickney. After whom was it named? Hint


Question 8 of 10
8. Phobos is closer to its planet than any other moon in the solar system is to their respective planets.


Question 9 of 10
9. Because of Phobos' speed and its proximity to Mars, there is an effect that will eventually cause the moon to break up (in 30-50 million years). What is this effect called? Hint


Question 10 of 10
10. Phobos and Deimos have been photographed many times over the decades since the advent of space travel. Mariner 9 was the first spacecraft to send back close up photos of the two moons. In what year was this? Hint



(Optional) Create a Free FunTrivia ID to save the points you are about to earn:

arrow Select a User ID:
arrow Choose a Password:
arrow Your Email:




Most Recent Scores
May 25 2024 : Guest 24: 9/10
Apr 25 2024 : slay01: 10/10
Apr 10 2024 : PurpleComet: 7/10
Mar 27 2024 : angostura: 10/10

Score Distribution

quiz
Quiz Answer Key and Fun Facts
1. The two natural satellites of Mars were discovered by an American astronomer in August of 1877. Who was he?

Answer: Asaph Hall

The discoveries were made nearly a week apart on August 12th and 18th at the US Naval Observatory in Washington, DC. Asaph Hall thought he had seen a moon on August 10th, but could not confirm it because of bad weather, delaying the official discovery until the 12th. While showing his new discovery to a colleague late on the 17th into the 18th, Hall discovered a second moon.

The names Phobos and Deimos came from Book XV of Homer's "Iliad".
2. The first of Mars' moons to be discovered was its outer moon, Deimos.

Answer: True

Despite being the smaller of the two Martian moons, Deimos, by virtue of being further away from the planet, was spotted first. The telescope used to discover the moons was a 26-inch (66 cm) refractor.
3. Deimos is an small, irregularly-shaped, moon with an orbital period nearly four times that of its brother Phobos. How long does it take for Deimos to orbit Mars?

Answer: 30.35 hours

With the Martian day lasting 24.7 hours and Deimos' orbital period a slightly higher 30.35 hours, there is actually a lapse of 2.7 days between when the sun sets and rises again (for an observer on the surface of Mars).

Seen from Mars, a Deimosian full moon would be about as bright as Venus as seen from Earth.
4. There are two craters on the surface of Deimos named for authors who wrote about the existence of two Martian moons in their works (prior to their actual discovery). Who were they?

Answer: Swift and Voltaire

In the early 17th century Johannes Kepler reasoned that Mars must have two moons, considering that Earth had one and Jupiter had four (known). Perhaps that is why Jonathan Swift referred to two moons orbiting Mars in his "Gulliver's Travels" (1726). A few years later, Voltaire (François-Marie Arouet) wrote of two Martian moons in his 1752 short science fiction story "Micromégas".
5. Just how small is Deimos? Its widest dimensions are 15 by 12.2 by 11 km, it has a surface area of 495.15 square km, and a volume of approximately how many cubic kilometres?

Answer: 1000

To be a bit more precise, the volume of Deimos is 999.78 km3. That makes it nearly 1/6th the size of Phobos. And a far cry from the size of our own Moon, which has a volume of 2.1958 × 10^10 km3.
6. Phobos, the inner of the two moons, has a quick orbital period, rising and setting twice during the Martian day (taking 4.25 hours to cross the sky, beginning again 11 hours later). Unlike Deimos, Phobos rises in the west and sets in the east.

Answer: True

Phobos and Deimos both orbit Mars in the same direction, but from the surface of Mars it looks as if they are going in opposite directions. The reason for this is that Phobos orbits the planet faster than it (the planet) rotates. Phobos' orbital period is a mere 7.66 hours!
7. The Phobian surface is more pockmarked than that of Deimos. The most prominent feature is a large crater named Stickney. After whom was it named?

Answer: The discoverer's wife

Astronomer Asaph Hall named the crater for his wife, Angeline Stickney Hall. Stickney was Angeline's maiden name. According to the Wikipedia page on Angeline Stickney, she was instrumental in encouraging Asaph to continue his efforts to find moons around Mars, when he was ready to give up.

There are a number of other named features on the surface of Phobos, most of them named for astronomers who studied Phobos and for characters and places in Jonathan Swift's "Gulliver's Travels".
8. Phobos is closer to its planet than any other moon in the solar system is to their respective planets.

Answer: True

At a distance of a mere 9,380 km, looking at Mars from the surface of Phobos would make it seem 6,400 times bigger than our Moon looks like from Earth. From the other direction, Phobos is not quite big enough to provide a full solar eclipse, despite its close proximity to the planet.
9. Because of Phobos' speed and its proximity to Mars, there is an effect that will eventually cause the moon to break up (in 30-50 million years). What is this effect called?

Answer: Tidal deceleration

Tidal deceleration means that the tidal bulges raised by the moon on their planet lag behind the moon, and cause the moon to decelerate in its orbit. In the case of Phobos, the moon gets about one metre closer to the planet every year.

Phobos will hit its Roche limit (the closest it can get to the planet before being destroyed by gravitational forces) at a distance of 3,620 km.
10. Phobos and Deimos have been photographed many times over the decades since the advent of space travel. Mariner 9 was the first spacecraft to send back close up photos of the two moons. In what year was this?

Answer: 1971

The Mariner program launched ten spacecraft between 1962 and 1973 with the intent to fly by Mercury, Venus and Mars. Seven of the missions were successful.

Mariners 1 and 2 were intended for Venus, but Mariner 1 was destroyed on liftoff. Mariner 2 completed its flyby of Venus in late 1962.

Mariners 3 and 4 were destined for Mars, but Mariner 3 malfunctioned. Mariner 4 completed its flyby of Mars in 1965.

Mariner 5 also went to Venus, in 1967.

Mariners 6 and 7 were both sent to Mars, completing their flybys in 1969.

Mariners 8 and 9 were also intended for Mars, but Mariner 8 was destroyed. Mariner 9 became Mars' first artificial satellite in 1971.

Mariner 10 was launched in 1973 and flew past both Venus and Mercury in 1974.
Source: Author reedy

This quiz was reviewed by FunTrivia editor rossian before going online.
Any errors found in FunTrivia content are routinely corrected through our feedback system.
Related Quizzes
This quiz is part of series Look to the Heavens:

Moons, moons, more moons, some dwarf planets, 'real' planets, and a few stars. Have fun!

  1. Luna Nostrum Average
  2. The Moon Rocks Average
  3. Where Can We See The Moon? Easier
  4. It's Your Planet Easier
  5. Fear and Dread Average
  6. The Galilean Moons Average
  7. Titans and Giants Average
  8. The Moons of Neptune Average
  9. Our Dwarf Planets Average
  10. Celestial Order Average
  11. The Sun Will Come Out Tomorrow Average
  12. Starlight Star Bright Average

Also part of quiz lists:
5/26/2024, Copyright 2024 FunTrivia, Inc. - Report an Error / Contact Us