Galaxy Types
The Milky Way is what type of galaxy?
Spiral galaxy
The Milky Way is on a collision course with what spiral galaxy?
Andromeda
The universe is approximately how old?
14 billion years
Black Holes have so much gravitational pull that not even ___________ can escape.
light
What are the 3 current scientific possibilities for the end of the universe?
The Big Crunch, The Big Freeze/Heat Death, The Big Rip
A scientist observes a galaxy that appears perfectly round with no visible spiral arms or disk structure. The galaxy contains mostly older, reddish stars with very little gas or dust. What type of galaxy is this most likely to be?
Elliptical galaxy
Every big galaxy we see appears to have a huge ___________________ in its heart.
black hole
Scientists believe the universe is expanding because they observe __________ when looking at most distant galaxies.
redshift
Antimatter totally destroys, or __________________, regular matter, turning it into pure energy.
annihilates
In the balloon model of universe expansion, what does the stretching of the balloon's surface best represent?
The expansion of space itself, causing distances between galaxies to increase
A galaxy has a bright central bulge surrounded by a flat disk of material, but without any spiral arm patterns. What type is it?
Lenticular galaxy
The youngest galaxies are
irregular.
What is the relationship between galaxy movement and the age of the universe?
If galaxies are moving away now, rewinding time shows they were once closer together
Nuclear _______________ produces elements heavier than hydrogen in stars.
fusion
Compare the three possible endings of the universe. Which scenario would most likely occur if gravity wins and the universe is pulled back into a single point?
The Big Crunch
The Milky Way is part of a small knot of galaxies called the _________ ___________, along with Andromeda and the Magellanic Clouds.
Local Group
What would happen if a spiral galaxy gradually lost most of its gas and dust over billions of years?
It would likely become a lenticular galaxy with mostly older stars.
How long after the Big Bang could nuclei capture electrons, forming the first atoms?
300,000 years
Quasi-stellar radio sources are better known as
Quasars
Describe the Big Rip.
The universe expands so quickly that it tears apart.
Galaxies that pour out significantly more energy than normal ones are called __________ ___________.
Active galaxies
Most elliptical galaxies are the result of
galactic collisions
Why is the cosmic microwave background radiation considered important evidence for the Big Bang theory?
It provides direct observation of the universe's condition 300,000-400,000 years after the Big Bang
Black holes occur when a star that is about _____ times the mass of the Sun dies and collapses under its own weight.
30
Describe the Big Freeze/Heat Death of the Universe
All objects in the universe would be at the same temperature, so no energy would be able to be transferred. All motion and time would come to a stop.