Questions for “Rogue planets wander the galaxy all alone”

A newfound planet (seen here in an illustration) is about the mass of Earth and has no sun. Instead, it floats through the galaxy alone.

NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

To accompany Rogue planets wander the galaxy all alone”


Before Reading:

1.   How do planets form? What force keeps planets orbiting their stars?  

2.   How do planets differ from asteroids and comets?  

During Reading:

1. How many planets without stars have astronomers found over the past 20 years?

2. What might be some reasons orphan planets no longer orbit a star?

3.  What is the official definition of a planet, according to the International Astronomical Union?

4.  What’s the difference between an orphaned planet and an asteroid or comet?  

5.  What is the difference between an orphan planet and a star?    

6.  How do scientists detect most planets outside our solar system? 

7.  What is gravitational lensing?

8   In what country is the Optical Gravitational Lensing Experiment (OGLE) located?

9.  Who is Nancy Grace Roman and why is she important?

After Reading:

1.  Use your imagination and describe what the environment would be like on an orphan planet if you were to travel to one.

2.  Explain why a space-based telescope can yield more information than a telescope on Earth.