The astronomer Edwin Hubble discovered that virtually all galaxies are moving away from us and the further away they are, the faster they are moving. What is the best explanation of this observation?

All of the material in the universe began at a central point and is expanding into preexisting space More test answers on https://studyhippo.com/fdsci-209/

What is a good example of the galaxies moving away due to expansion is..?

Buttons attached to an expanding balloon. More test answers on https://studyhippo.com/phy-201-ch-18/

What is a likely candidate for the majority of the dark matter in galaxies?

Subatomic particles that we have not yet detected More test answers on https://studyhippo.com/mastering-astronomy-chapter-16-17/

Which of the following features is not a feature of central dominant galaxies?

They are often spiral galaxies. More test answers on https://studyhippo.com/astronomy-chapter-21/

What are the basic shapes into which astronomers classify most galaxies?

– irregular – elliptical – spiral More test answers on https://studyhippo.com/2-11-quiz-3/

In a photo like the Hubble Deep Field, we see galaxies in many different stages of their lives. In general, which galaxies are seen in the earliest (youngest) stages of their lives?

the galaxies that are farthest away More test answers on https://studyhippo.com/chapter-16-concept-quiz/

The spectra of most galaxies show redshifts. This means that their spectral lines _____.

Have wavelengths that are longer than normal. More test answers on https://studyhippo.com/astronomy-ch-5/

How are rotation curves of spiral galaxies determined beyond radii where starlight can be detected?

through observations of the 21 cm line of atomic hydrogen More test answers on https://studyhippo.com/astro-practice-2/

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Galaxies Flashcards, test questions and answers

Discover flashcards, test exam answers, and assignments to help you learn more about Galaxies and other subjects. Don’t miss the chance to use them for more effective college education. Use our database of questions and answers on Galaxies and get quick solutions for your test.

What is Galaxies?

Galaxies are large collections of stars, gas, dust, and dark matter bound together by gravity. They come in many different shapes and sizes, from the spiral galaxies like our own Milky Way to elliptical galaxies with no well-defined structure. Our own Milky Way galaxy is estimated to contain between 100 and 400 billion stars within a disc-shaped structure about 100,000 light years across. It has four main arms of stars that all spiral into a central bulge at its core. The outer edges of the Milky Way are home to vast clouds of interstellar gas and dust known as the galactic halo which is believed to be where much of the galaxy’s dark matter resides. In addition to stars and gas, galaxies also contain an abundance of dark matter an invisible form of matter that makes up most of the mass in galaxies but does not emit or absorb any visible light itself. Dark matter remains one of astronomy’s greatest mysteries as it is still not fully understood what it is made up off or how it behaves on cosmic scales. Galaxies vary greatly in size from tiny dwarf galaxies with only a few million stars up to supermassive black holes surrounded by hundreds of billions or even trillions star systems spread out over millions or even billions light years worth distance. Many smaller galaxies orbit larger ones such as our Milky Way’s satellite dwarf galaxie the Large Magellanic Cloud which orbits around us at a distance of some 160 000 light years away. All in all, Galaxies are fascinating objects whose study has helped us understand more about our universe and our place within it through their evolution over time and what they tell us about cosmology and astrophysics in general.