The Basic Astronomy quiz

By: Torrance Grey

How many planets are in our solar system?

If you said "nine," you've revealed yourself as a quiz-taker Of A Certain Age. The onetime ninth planet, Pluto, was downgraded to dwarf-planet status in 2006, despite the protests of astronomy buffs who loved the little guy.

How many natural satellites does the Earth have?

Of course, we're talking about the moon, Earth's only natural satellite. The planet has an ever-changing number of man-made satellites; they provide us with GPS systems, radio and more.

Most of the planets in our solar system are named after what?

Seven of the eight planets, and the dwarf ninth, Pluto, are named for gods in the Roman pantheon, which are essentially Greek gods with new names. The exception? Planet Earth, our home. It's named after, uh, soil.

"The Red Planet" is the poetic name for ... ?

If you're looking up at the night sky and see what looks like a reddish star, but it isn't twinkling ... well, chances are you're looking at Mars. The reddish color of its soil is due to a high iron oxide content.

What's a group of stars that resemble an earthly object called?

Orion and the Big Dipper are two of the most-recognized constellations. Others, like "the sextant," or "the serpent bearer," are based on objects or phenomena that no longer really exist, making these constellations even harder to recognize.

Which planet has the Great Red Spot?

It's the largest planet in our solar system, great Jupiter. And what is the Red Spot? It's a high-pressure region, a storm that's been raging since the early 19th century at least. Imagine if there were poor Jovians living there: "Can we get a nice day, like just one or two? Just a short break?"

Saturn is best known for its gorgeous ______.

Hey, maybe we shouldn't rule out "sunrises"; we've never been actually been there! But people using a telescope for the first time invariably want to point it at Saturn, to see its marquee feature, its rings.

Is the Earth considered an astronomical body?

This answer should be obvious, but it tricks some people because the Earth is our home and vantage point. But, as Carl Sagan pointed out with his "Pale Blue Dot" metaphor, Earth is just another spot in the vastness of the universe.

A ball of ice and dust with a long, glowing tail is called what?

The ancient Romans referred to this astronomical phenomenon as a "coma stellata," or "a star with long hair." Now we call it a comet, and some of the more famous ones are Halley's Comet and Comet Hale-Bopp.

What's the name of the galaxy we live in?

How'd our galaxy get such a casual name? For crying out loud, "Milky Way" is also a candy bar frequently given out as minis at Halloween! Well, the name's a translation from the Latin "via lactea," because, seen from Earth, it resembles a cloudy, milky road of stars.

True or false: Ursa Major and the Big Dipper are the same thing.

This is a common misconception, but the Big Dipper is only part of Ursa Major. After all, Ursa Major is "the Big Bear," and a bear and a dipper are pretty hard to mistake for each other, even in the loose framework of constellations.

Which of these four planets is not a "terrestrial planet"?

A terrestrial planet is one whose composition is mostly rock and metal. Earth is one, though this definition might seem odd to us, as we mostly encounter the soil that is a fine layer atop earth's crust. The missing terrestrial planet above is Venus, meaning that the terrestrial planets are the inner four, nearest to the sun.

Beyond the terrestrial planets, we find ... ?

The first two planets beyond Mars are gas giants, meaning they are made primarily of hydrogen and helium. Uranus and Neptune are the ice giants, composed of frozen oxygen, carbon, nitrogen and sulfur.

On which astronomical object would you find the Sea of Tranquility?

The smooth, dark patches on the moon as referred to as "seas," or "maria" in Latin. One of the largest and best-known is the Mare Tranquilltatis, or "Sea of Tranquility." It is where the Apollo 11 lunar lander touched down.

When a large star collapses under its own weight, what does it become?

A black hole occurs when a massive star collapses under its own weight. Not even light can escape the gravitational pull of a black hole—which is, of course, why we perceive them as black.

Which planet's moons are named (in translation) "fear" and "dread"?

Mars is named for the god of war, so it shouldn't surprise anyone that its moons are "Phobos" and "Deimos," the Greek words for "fear" and "dread." They accompany war, after all.

What is an exoplanet?

Like comet hunting, exoplanet hunting is an ongoing pursuit of astronomers. It helps to have the resources of an observatory and a university behind you, however. To date, a little more than 4,000 exoplanets are known to exist.

When we talk about a star's brightness, we refer to its what?

Here's what confuses beginning astronomers, though. "Magnitude" is actually measured backward, to our way of thinking. That is, the brightest stars actually have a negative magnitude.

A light-year is a measure of what?

It sounds like it should be time, doesn't it? But a light-year is the distance that a particle of light can travel in one year. It's nearly 6 trillion miles, so if you're planning a vacation, maybe scale down your travel plans a little.

In contrast, an astronomical unit is how many miles?

Ah, that's better. Well, a little. 93 million miles is the distance between the earth and the sun, and is commonly used to refer to distances within our solar system, within which light-years would be far too large a measure.

In which constellation would you find the star Betelgeuse?

Betelgeuse is the left shoulder of Orion the Hunter (well, left as you're looking at it; it would be his right if he were an actual person). Fun fact: When you look at Betelgeuse, you are gazing at the single largest object it's possible to see unaided from Earth.

Which of these terms is used to refer to the moon?

"Lunar" is the most common term. However, we also have words like "selenology" for the geology of the moon, and "pericynthion" for the point at which the moon is closest to the Earth. Where do these names come from? Luna, Selene and Cynthia are all moon-goddess names from mythology.

Our solar system's asteroid belt is between which two planets?

The asteroid belt is planetary material left over from the formation of the solar system. It might have come together to form an actual planet, but the contradictory pulls of Mars' gravity and Jupiter's didn't allow this, and so it has remained a group of orbiting asteroids, with one dwarf planet in the mix.

True or false: A planet can exist without orbiting a star.

Such celestial objects are known by several romantic names: "rogue planets," "nomad planets" and "orphan planets." They orbit a galactic center directly, like stars and star systems do. Life on such planets seems less likely than on those with the sustaining resources of a star.

Why does the moon have many craters and the Earth relatively few?

Meteors tend to burn up in the Earth's atmosphere. Therefore, only the largest hit and make craters. The moon has no such atmosphere and is pocked with craters from the impacts.

What kind of celestial objects are brown dwarfs?

The line between a huge exoplanet and a nonviable star is a fuzzy one; sometimes astronomers aren't sure what they're looking at. By "nonviable star," we mean one that doesn't have sufficient mass to create nuclear fusion reactions, as our sun does. This makes them little different from a huge gas-giant planet.

The "local group" is a group of what?

On "Cosmos," Neil DeGrasse Tyson called the Local Group a line in our "celestial address." It goes: Earth, the Solar System, the Milky Way, the Local Group, the Virgo Supercluster to the Observable Universe. Whew!

The word "corona," meaning "crown," describes a feature of ... ?

The sun's corona is the beautiful and somewhat irregular outer halo. Outside of photography, it's best seen during a total solar eclipse. (Even at totality, don't skip eye protection, please).

Where would you find the celestial body called Ceres?

Ceres is a dwarf planet, the largest object in our solar system's asteroid belt. It's named for the Roman goddess of agriculture, so in Greece they call it "Demeter," their equivalent of the goddess Ceres.

Titan is a moon of which planet?

Some people believe, erroneously, that because Saturn has rings, it does not have moons as well. Not true: Saturn has eight moons, more than any other planet in the Solar System.

Which of these is NOT one of Jupiter's moons?

Jupiter's moons are all named after the great Roman god's wives and mistresses. Oberon, in contrast, is a fairy-king figure from European literature (especially Shakespeare) and is a moon of Uranus. It's less poetically known as Uranus IV.

What's believed to be at the center of our galaxy?

We hate to mark you down if you chose "God"—it's so poetic!—but the astronomically correct answer is "a massive black hole," which has been named "Sagittarius A." It emits detectable radio energy, though its actual existence can't be confirmed with current methods.

An eclipse is one of the most entertaining events to view in astronomy. What exactly is it?

From Earth, there are fundamentally two kinds of eclipses: solar (when the moon blocks the sun) and lunar (when the Earth blocks the moon). Solar eclipses are amazing to watch because of a remarkable coincidence: The moon is 400 times smaller than the sun, but 400 times closer to Earth as well, resulting in a perfect "cap."

What is the "event horizon"?

To be fair, there is a broader definition of "event horizon" in the theory of general relativity, but we're not going to worry about that here. (Plus, we can't explain it because the definition goes over our heads). For our purposes, when you're approaching a black hole, the event horizon is the point at which suddenly no one's posting on your Facebook wall anymore.

Which of these luminaries of early astronomy championed the heliocentric solar system?

Galileo believed that the sun was the center of what would become known as the solar system. At the time, most people believed in the geocentric system put forth by Ptolemy. Tycho Brahe, meanwhile, proposed a "mixed" system in which the sun and stars revolved around the Earth, but the known planets revolved around the sun—this explained (erroneously) confusing aspects of their movement in the sky.

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Image: cemagraphics / E+ / Getty Images

About This Quiz

Who doesn't like to look up at the night sky and find the familiar constellation of Orion, or determine true north by the Pole Star? Who didn't get at least a little involved in the total-solar-eclipse craze of 2016? Humans have always felt a connection to the skies and the objects in it. Early on, we considered the sun and moon to be gods. Later, civilizations like the Greeks and the Chinese invented a system of fortunetelling involving the patterns of the stars. Today, our guides to understanding the universe include astrophysicist and science educator Neil DeGrasse Tyson, who revived the popular show "Cosmos" in 2014. 

Maybe science, in general, wasn't your thing in school. Even so, we're willing to bet that you picked up a bit of astronomy knowledge along the way. You might know, for example, where in our solar system the dwarf planet Ceres is located. Or which planet's moon are named after the lovers of the great god Zeus (well, Zeus in the Greek; to give you his Roman name would be too great a giveaway). See? Did the answers leap to mind? If not, you'll find them out within our quiz. 

So, settle down with a few astronomy-themed snacks—we recommend Starburst candy or a Milky Way bar—and test your astronomy knowledge with our quiz. 

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