Multiple choice

How many galaxies is the known universe made of?

  1. 5

  2. 5 billion

  3. 5 million

  4. 50 billion

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Current estimates from deep-field observations, such as those from the Hubble Space Telescope, suggest that the observable universe contains at least 50 billion to 2 trillion galaxies.