Time, Space and Everything in Between: The Astrophysics Quiz

By: Staff
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About This Quiz

The field of astrophysics covers some of the biggest questions about the universe. How did it form? What will happen to it? How do solar systems form? What are stars made of? Is time travel possible? Test your smarts on astrophysics with this quiz.

The sun is made mostly from what element?

The sun is almost 75 percent hydrogen.

What is the process that "powers" stars?

The energy given off by stars comes from the fusion of atoms within the star.

Most stars, when plotted into a graph of color and brightness, fall into a band known as the …

The main sequence shows the changes that stars of a given mass undergo throughout their lives.

The final stage for the most massive stars is either a massive explosion known as a supernova or gravitational collapse into a …

All the mass of a truly massive star can sometimes collapse into a single point of infinite gravity known as a black hole.

The Kepler space telescope has found more what than any other telescope?

Kepler has spotted about two-thirds of all the planets outside our solar system that have been discovered so far.

Variances in the sun's magnetic field can cause some areas on the sun's surface to be slightly cooler than the surrounding area. These areas are known as what?

Sunspots appear as dark areas on the sun's surface because they're cooler, although they're still well over 7,000 degrees Fahrenheit (4,000 degrees Celsius).

What is the radial-velocity method of detecting exoplanets?

A massive exoplanet pulls its parent star back and forth as it revolves around the star. The slight changes in wavelength in the light emitted by the star can be measured.

A planet that does not orbit any star, instead wandering through the galaxy alone, is called what?

Rogue planets move through the galaxy independent of any solar system.

What is the stellar equivalent of a rogue planet?

Intergalactic stars move through the enormous spaces between galaxies. They may have been dislodged by galaxies colliding or accelerated into intergalactic space by supermassive black holes.

Molecular clouds are regions where interstellar gases are slightly more dense, permitting molecules to form. These massive clouds can also give birth to what?

Molecular clouds are also known as stellar nurseries, since stars are born there.

What was the first (and so far only) spacecraft to enter the interstellar medium?

Voyager I left our solar system and is now traveling through the interstellar medium, the space between solar systems.

What is the most widely accepted theory about the origin of the universe?

The big bang theory posits that the entire universe was concentrated into a single point roughly 13.8 billion years ago, and that it expanded rapidly to form what we know as the universe.

The faint glow of radiation permeating the universe, considered a key element of the big bang theory, is also known as the …

The cosmic microwave background is the oldest light we can see, a remnant of the energy that filled the universe's earliest eras.

What is the term for the apparent increase in wavelengths of light as the object emitting them and an observer move farther apart?

Redshift can be the result of actual movement of one object away from another or apparent movement due to the expansion of the universe.

A theoretical "tube" connecting two different points in space-time is called what?

A wormhole could allow rapid travel across vast distances or even time travel.

The theory that the universe will continue expanding until all energy is evenly distributed throughout the universe is called what?

Continued expansion, leading to the heat death of the universe, is one of the leading theories on the universe's ultimate fate.

Observations of the universe suggest there is a great deal more matter present than what is visible. How do physicists account for the discrepancy?

Dark matter doesn’t seem to interact with the electromagnetic spectrum in any way, making it effectively invisible. What it actually is and whether it really exists is a matter of great debate and experimentation.

The matter in the universe that we can see and interact with (as opposed to dark matter and dark energy) is known as …

Baryonic matter represents a small percentage of the expected amount of matter in the universe, which is why theories about dark energy and dark matter are so important.

When a star first forms, it is surrounded by a disk of gas and dust that may eventually form planets. What is the disk called?

A protoplanetary disk can coalesce into planets orbiting the star.

The flow of high-energy particles from a star, pushed by the heat of the star's corona, is known as what?

The stellar wind plays a prominent role in star system creation.

What kind of star will the sun become in the final stages of its life?

The sun will expand and become an enormous red giant before collapsing into a white dwarf.

What is at the center of most (possibly all) galaxies?

Most galaxies seem to revolve around a supermassive black hole.

What is the event horizon of a black hole?

A black hole has infinite gravity — get close enough, and nothing can escape its pull.

What is the name of the invisible, radio wave-emitting object at the center of our galaxy that astronomers suspect is a supermassive black hole?

Stars passing in front of Sagittarius A have allowed physicists to estimate the object's mass at more than 4 million times that of the sun.

Analyzing the spectra of the light being emitted by a star allows astronomers to determine what?

Spectral analysis shows astronomers the relative quantities of various chemical elements in the star.

In the Morgan–Keenan classification system for stars, the sun is classified G2V. What do the G and the 2 indicate?

Stars are classified by their hotness, first on a scale that goes O, B, A, F, G, K and M, then by numbers from zero to 9. The final letter, V, indicates that our sun is a main sequence star.

The two primary classifications of galaxies are elliptical and what else?

Spiral galaxies can either have a pinwheel shape or, more commonly, a central bar with spiral arms.

What accounts for most galaxies with odd or unusual shapes?

When galaxies collide, the result can be strange-looking galaxies with almost no shape (just formless clouds of stars) or really distinctive shapes (like a doughnut-shaped galaxy).

Which part of a star is hotter, the core or the surface?

The core is significantly hotter, since a constant nuclear fusion reaction is blasting out gamma radiation.

What is the term for a system of two stars revolving around each other?

Binary stars can develop into strange and exotic systems, such as systems where one star draws energy and matter from the other.

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