Quiz of the Day
Red Planet: Exploring Mars
Thursday, 3 September 2026
NASA's Viking 2 lander touched down on Mars on 3 Sep 1976 — covering Mars missions, rovers, geography and the science of the Red Planet
1. In which year did NASA's Viking 2 lander successfully touch down on the surface of Mars?
- 1974
- 1978
- 1976
- 1980
Viking 2 landed in the Utopia Planitia region on September 3, 1976, joining its twin Viking 1 which had touched down in Chryse Planitia weeks earlier on July 20. Each Viking mission paired an orbiter with a lander, and the landers carried experiments designed to search for signs of microbial life in the Martian soil. The results were famously ambiguous and are still debated by scientists today.
2. What substance gives Mars its distinctive reddish colour?
- Sulfur deposits
- Copper oxide
- Red sandstone
- Iron oxide (rust)
Mars looks red because its surface is coated with iron oxide, the same compound that makes rust on Earth. Fine dust rich in this oxidized iron covers much of the planet and is stirred up into the atmosphere by winds and dust storms. Beneath the reddish dust, much of the underlying rock is actually darker and greyer.
3. Which Martian feature is the tallest volcano in the entire Solar System?
- Arsia Mons
- Ascraeus Mons
- Olympus Mons
- Elysium Mons
Olympus Mons rises roughly 22 kilometres above the surrounding plains, making it about two and a half times the height of Mount Everest above sea level. It is a shield volcano with gently sloping sides, and its base is so wide it would cover much of the state of Arizona. Mars's lack of moving tectonic plates allowed the volcano to keep growing over a single hot spot for a very long time.
4. How many natural moons does Mars have?
- None
- Seven
- Four
- Two
Mars has two small, potato-shaped moons named Phobos and Deimos, both discovered by American astronomer Asaph Hall in 1877. Their names come from Greek mythology, referring to the personifications of fear and dread who accompanied the war god Ares (the Greek counterpart of Mars). Both moons are thought to be either captured asteroids or debris left over from a large impact.
5. Counting outward from the Sun, Mars is which planet in the Solar System?
- Third
- Fourth
- Fifth
- Sixth
Mars is the fourth planet from the Sun, orbiting just beyond Earth and inside the asteroid belt. It sits on average about 228 million kilometres from the Sun and takes roughly 687 Earth days to complete one orbit. This makes a Martian year nearly twice as long as an Earth year.
6. What is the name of the vast canyon system that stretches for thousands of kilometres along Mars's equator?
- Kasei Valles
- Valles Marineris
- Noctis Labyrinthus
- Hellas Basin
Valles Marineris runs for over 4,000 kilometres, making it one of the largest canyon systems in the Solar System — long enough to stretch across much of the United States. It is far deeper and longer than Earth's Grand Canyon, reaching depths of up to about 7 kilometres in places. The canyon is named after NASA's Mariner 9 spacecraft, which photographed it in the early 1970s.
7. Which NASA rover landed in Gale Crater in 2012 using a rocket-powered 'sky crane' to lower it to the surface?
- Opportunity
- Curiosity
- Spirit
- Perseverance
The car-sized Curiosity rover touched down in Gale Crater on August 6, 2012, after a descent nicknamed the 'seven minutes of terror.' A rocket-powered sky crane hovered above the surface and lowered the rover on cables before flying away to crash at a safe distance. Curiosity has since found strong evidence that its landing site once held a habitable, water-rich environment.
8. What was the name of the first wheeled rover to operate on the surface of Mars, delivered by the Mars Pathfinder mission in 1997?
- Sojourner
- Zhurong
- Curiosity
- Spirit
Sojourner was a tiny, microwave-oven-sized rover that rolled onto Mars in July 1997 as part of the Mars Pathfinder mission. It was named after Sojourner Truth, the American abolitionist and women's rights advocate. Though it was designed to last only about a week, it kept working for nearly three months and proved that mobile robotic exploration of Mars was possible.
9. Which pair of identical NASA rovers both landed on Mars in early 2004?
- Phoenix and InSight
- Curiosity and Perseverance
- Viking 1 and Viking 2
- Spirit and Opportunity
The twin Mars Exploration Rovers, Spirit and Opportunity, bounced to the surface inside protective airbags in January 2004. Both were planned for missions of about 90 days, but Opportunity astonishingly kept exploring until 2018, travelling more than 45 kilometres. They found mineral evidence that liquid water once flowed across the Martian surface.
10. In which crater, a site believed to have once held an ancient lake and river delta, did the Perseverance rover land in 2021?
- Utopia Planitia
- Gale Crater
- Gusev Crater
- Jezero Crater
Perseverance touched down in Jezero Crater on February 18, 2021, chosen because it appears to contain the remains of an ancient river delta and lake. Such deposits are ideal places to search for chemical signs of past microbial life. The rover is also collecting and sealing rock samples that a future mission may one day return to Earth.
11. What was the name of the small NASA helicopter that made the first powered, controlled flight on another planet?
- Ingenuity
- Dragonfly
- Beagle 2
- Sojourner
Ingenuity, a roughly 1.8-kilogram helicopter carried to Mars by the Perseverance rover, made history with its first flight on April 19, 2021. Flying in Mars's thin atmosphere is extremely difficult because the air is far less dense than Earth's, so its rotors had to spin very fast. Originally planned for just five test flights, it ultimately completed more than 70 before a rotor was damaged in early 2024.
12. Which gas makes up roughly 95% of Mars's thin atmosphere?
- Methane
- Nitrogen
- Oxygen
- Carbon dioxide
Mars's atmosphere is about 95% carbon dioxide, with small amounts of nitrogen and argon. It is extremely thin — surface pressure is less than one percent of Earth's — so liquid water cannot easily remain stable on the surface. This tenuous air still supports weather, including winds, clouds and enormous dust storms that can sometimes engulf the whole planet.
13. Which of Mars's two moons is the larger and orbits closer to the planet?
- Phobos
- Deimos
- Charon
- Titan
Phobos is the larger of the two Martian moons, measuring only about 22 kilometres across, and it orbits remarkably close to the planet's surface. It circles Mars so quickly that it rises and sets multiple times a day as seen from the ground. Phobos is slowly spiralling inward and is expected to either break apart or crash into Mars in tens of millions of years.
14. Which country's Mars Orbiter Mission, nicknamed Mangalyaan, reached Mars orbit in 2014?
- United Arab Emirates
- China
- India
- Japan
India's Mars Orbiter Mission, known as Mangalyaan, entered orbit around Mars on September 24, 2014. The achievement made India the first Asian nation to reach Mars and the first country in the world to succeed on its very first attempt. The mission was also celebrated for its remarkably low cost compared with other interplanetary probes.
15. Which spacecraft performed the first successful flyby of Mars in 1965, returning the first close-up images of another planet?
- Mariner 9
- Mars 3
- Mariner 4
- Viking 1
NASA's Mariner 4 flew past Mars in July 1965 and sent back the first close-up photographs ever taken of another planet. The 22 grainy images revealed a cratered, Moon-like surface, dashing popular hopes of finding canals or lush landscapes. The data also confirmed that Mars had a very thin atmosphere, reshaping scientists' understanding of the Red Planet.