Galaxies Practice Questions
19 free Galaxies practice questions for the Static GK. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following is the correct classification of our home galaxy, the Milky Way?
- A Giant Elliptical Galaxy
- B Irregular Galaxy
- C Barred Spiral Galaxy
- D Lenticular Galaxy
Correct answer: Barred Spiral Galaxy
The Milky Way is classified as a barred spiral galaxy because it has a central bar-shaped structure composed of stars. It features distinct spiral arms that extend outward from the ends of this bar.
Which galaxy is the nearest large neighbor to the Milky Way and is expected to collide with it in about 4.5 billion years?
- A Triangulum Galaxy
- B Andromeda Galaxy
- C Sombrero Galaxy
- D Whirlpool Galaxy
Correct answer: Andromeda Galaxy
The Andromeda Galaxy (M31) is the closest large spiral galaxy to us. Observations show that the two galaxies are moving toward each other and will eventually merge into a single elliptical galaxy.
Who developed the 'Tuning Fork' diagram to classify galaxies based on their visual morphology?
- A Edwin Hubble
- B Carl Sagan
- C Stephen Hawking
- D Johannes Kepler
Correct answer: Edwin Hubble
Edwin Hubble created the Hubble Sequence in 1926. It categorizes galaxies into four main types: ellipticals, lenticulars, spirals, and irregulars based on their appearance.
What is the name of the supermassive black hole located at the galactic center of the Milky Way?
- A Cygnus X-1
- B Sagittarius A*
- C Messier 87
- D Ton 618
Correct answer: Sagittarius A*
Sagittarius A* (pronounced Sagittarius A-star) is a bright and very compact astronomical radio source. It contains roughly 4 million times the mass of our Sun.
Which type of galaxy contains mostly old stars and very little gas or dust, often appearing as featureless ellipsoids?
- A Barred Spiral Galaxy
- B Elliptical Galaxy
- C Irregular Galaxy
- D Active Galaxy
Correct answer: Elliptical Galaxy
Elliptical galaxies have exhausted most of their interstellar medium, meaning star formation has largely ceased. They range in shape from nearly spherical to highly elongated.
The Large and Small Magellanic Clouds are examples of what type of galaxy?
- A Spiral Galaxies
- B Elliptical Galaxies
- C Irregular Galaxies
- D Lenticular Galaxies
Correct answer: Irregular Galaxies
The Magellanic Clouds are dwarf irregular galaxies that orbit the Milky Way. They are visible from the Southern Hemisphere and serve as important laboratories for studying star formation.
What is the name of the galactic group that contains the Milky Way, Andromeda, and about 50 other smaller galaxies?
- A Virgo Supercluster
- B Local Group
- C Orion Arm
- D Laniakea Supercluster
Correct answer: Local Group
The Local Group is a collection of galaxies spanning approximately 10 million light-years. It is dominated by the Milky Way and Andromeda, which make up the majority of its mass.
Which component of a spiral galaxy contains the oldest stars and surrounds the galactic disk in a spherical distribution?
- A The Galactic Bar
- B The Spiral Arms
- C The Galactic Halo
- D The Accretion Disk
Correct answer: The Galactic Halo
The halo is a large, spherical region surrounding a galaxy that contains globular clusters and 'Population II' stars. These stars are metal-poor and among the oldest in the universe.
The 'Sombrero Galaxy' (M104) is famous for its bright nucleus and a large, dark lane of what material?
- A Frozen Nitrogen
- B Molecular Hydrogen
- C Interstellar Dust
- D Liquid Hydrogen
Correct answer: Interstellar Dust
M104 features a prominent ring of dust that encircles its bulbous core. This dust lane is a site of intense star formation and gives the galaxy its hat-like appearance when viewed edge-on.
What does the term 'Quasar' stand for in astronomy?
- A Quick Stellar Radio Anomaly
- B Quantum Star Radiation
- C Quadruple Star System
- D Quasi-stellar Radio Source
Correct answer: Quasi-stellar Radio Source
Quasars are extremely bright and distant active galactic nuclei. They are powered by gas spiraling into supermassive black holes at relativistic speeds, emitting enormous amounts of energy.
In the Hubble classification system, what does the letter 'c' represent in a 'Sc' spiral galaxy?
- A Tightly wound spiral arms
- B Prominent central bulge
- C Loosely wound spiral arms
- D Circular rotation pattern
Correct answer: Loosely wound spiral arms
Spiral galaxies are sub-classified from 'a' to 'c' (and sometimes 'd'). Sc galaxies have a relatively small central bulge and very loosely wound, patchy spiral arms.
Approximately how many years does it take for the Sun to complete one orbit around the center of the Milky Way?
- A 22.5 million years
- B 2.25 billion years
- C 25,000 years
- D 225 million years
Correct answer: 225 million years
This period is known as a Galactic Year or Cosmic Year. The Sun travels at about 220 kilometers per second to cover this massive orbital path.
Which of these is a 'Lenticular Galaxy', often described as an intermediate between spiral and elliptical galaxies?
- A M31
- B M87
- C Irr Galaxy
- D S0 Galaxy
Correct answer: S0 Galaxy
Lenticular galaxies (S0) have a disk-like shape but lack the prominent spiral arms of a standard spiral. They have used up most of their interstellar matter and consist mainly of old stars.
The 'Whirlpool Galaxy' (M51) is a classic example of which phenomenon?
- A A galaxy slowly being consumed by a black hole
- B A dying elliptical galaxy
- C A starburst irregular galaxy
- D An interacting grand-design spiral galaxy
Correct answer: An interacting grand-design spiral galaxy
M51 is famous for its interaction with the smaller dwarf galaxy NGC 5195. This gravitational interaction has enhanced the structure of its spiral arms, making it a 'grand-design' spiral.
What is the 'Great Attractor'?
- A A giant black hole at the edge of the universe
- B A hypothetical dark energy concentration
- C A massive star about to go supernova
- D A gravitational anomaly attracting galaxies
Correct answer: A gravitational anomaly attracting galaxies
The Great Attractor is a massive concentration of mass that is pulling the Milky Way and thousands of other galaxies toward it. Its exact nature is difficult to study because it is obscured by the Milky Way's disk.
Which galaxy was the first to have its distance measured by Edwin Hubble, proving that galaxies exist outside the Milky Way?
- A Andromeda
- B Triangulum
- C NGC 6822
- D Messier 81
Correct answer: Andromeda
In 1923, Hubble identified Cepheid variable stars in the 'Andromeda Nebula'. By calculating their distance, he proved it was a separate galaxy far beyond our own.
Which type of galaxy is characterized by a high rate of star formation, often triggered by a collision?
- A Starburst Galaxy
- B Quiescent Galaxy
- C Lenticular Galaxy
- D Seyfert Galaxy
Correct answer: Starburst Galaxy
Starburst galaxies consume their gas reservoirs to create new stars at a rate hundreds of times faster than a typical galaxy. This often results in intense infrared radiation.
The Milky Way is part of a larger supercluster of galaxies named after the Hawaiian word for 'immense heaven'. What is it?
- A Laniakea
- B Shapley
- C Hydra-Centaurus
- D Coma
Correct answer: Laniakea
Defined in 2014, the Laniakea Supercluster contains approximately 100,000 galaxies. It encompasses the Virgo Supercluster, which in turn contains our Local Group.
What is the 'Galactic habitable zone'?
- A A galactic region favorable for life
- B The region inside a black hole
- C The center of a galaxy's spiral arm
- D The intergalactic void between galaxies
Correct answer: A galactic region favorable for life
This zone is far enough from the dangerous radiation of the galactic center but close enough to have sufficient heavy elements for planet formation. In the Milky Way, it is believed to be a ring-shaped region about 25,000 light-years from the center.