Why would few stars actually collide?

Stars are separated by vast distances

Which smaller galaxy may join the encounter?

The Large Magellanic Cloud only

What may happen to the Sun's position?

It could be flung to a different region of the merged galaxy

It will crash into another star

What did a 2025 study suggest about the merger?

There may be only about a 50 percent chance within 10 billion years

Andromeda Collision Quiz: When Our Galaxy Meets Its Neighbor

The nearest large galaxy is shifting toward us rather than away, and this Andromeda collision quiz explores what may happen billions of years from now. Play an interactive set of 10 questions on blueshift, Vesto Slipher, the distance to Andromeda, the predicted merger, Milkomeda, why stars rarely collide, the Triangulum galaxy, the Sun's fate and newer studies that question the timing.

Start Andromeda Collision Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Distance
Roughly how far away is the Andromeda galaxy?
Motion
How do we know Andromeda is approaching?
Slipher
Who first measured Andromeda's approach in 1912?
Speed
Roughly how fast is Andromeda approaching?
When
When did a 2012 Hubble study predict the collision?
Name
What nickname is given to the merged galaxy?
Stars
Why would few stars actually collide?
Third
Which smaller galaxy may join the encounter?
Sun
What may happen to the Sun's position?
New
What did a 2025 study suggest about the merger?

Explanations: answer key for all 10 questions

Q1: Roughly how far away is the Andromeda galaxy?
Answer: About 2.5 million light-years
It is visible to the naked eye in dark skies.
Q2: How do we know Andromeda is approaching?
Answer: Its light is blueshifted
Blueshift means motion toward us.
Q3: Who first measured Andromeda's approach in 1912?
Answer: Vesto Slipher
He used spectra of its light.
Q4: Roughly how fast is Andromeda approaching?
Answer: About 110 km per second
Gravity pulls the galaxies together.
Q5: When did a 2012 Hubble study predict the collision?
Answer: In about 4 to 5 billion years
Later studies added uncertainty.
Q6: What nickname is given to the merged galaxy?
Answer: Milkomeda
It would likely be an elliptical galaxy.
Q7: Why would few stars actually collide?
Answer: Stars are separated by vast distances
Galaxies are mostly empty space.
Q8: Which smaller galaxy may join the encounter?
Answer: Triangulum
It is also in the Local Group.
Q9: What may happen to the Sun's position?
Answer: It could be flung to a different region of the merged galaxy
The Sun itself would likely survive.
Q10: What did a 2025 study suggest about the merger?
Answer: There may be only about a 50 percent chance within 10 billion years
Uncertainties in motions matter.

Andromeda Collision Quiz – When Our Galaxy Meets Its Neighbor

The Andromeda galaxy, about 2.5 million light-years away, is the largest galaxy in the Local Group. In 1912 Vesto Slipher found its light was blueshifted, showing it is approaching the Milky Way at about 110 km per second.

A 2012 Hubble study predicted a head-on collision in about 4 to 5 billion years, forming a merged galaxy nicknamed Milkomeda. Because stars are so far apart, few would actually collide, but the Sun could be flung to a new region.

The Triangulum galaxy may also be involved. A 2025 study using newer data suggested only about a 50 percent chance of a merger within 10 billion years, showing how uncertain the future remains.

What This Quiz Teaches

Space fans and students will enjoy these questions.

How far Andromeda is
How we know it approaches
When a collision might happen
What it would look like
Why predictions changed

Did You Know?

Andromeda is also called Messier 31.
It contains about a trillion stars.
Its disk would span several full Moons in our sky if brighter.
Gas clouds would trigger new star formation.
The Large Magellanic Cloud may merge with the Milky Way first.