These are my planet and solar system class objects.

planet.rb

@@ -0,0 +1,70 @@
+class SolarSystem
+  attr_reader :planets
+
+  def intialize(planets)
+    planets.each do |planet|
+      @planets[planet.name] = planet
+    end
+  end
+
+  def add_planet(x)
+    @planets[x.name] = x
+  end
+
+  def remove_planet(planet_name)
+    @planets[planet_name] = nil
+  end
+
+  def name_of_planet(position)
+    planet_in_position = @planets[position]
+
+    planet_in_position.class #=> Planet
+    planet_in_position.colonized? #=> true or false
+    @planets[position].name
+  end
+
+  def distance_between(planet1, planet2)
+
+  end
+end
+
+class Planet
+  attr_reader :name, :earth_age
+
+  def initialize(options)
+    @name      = options[:name]
+    @mass      = options[:mass]
+    @rotation  = options[:rotation]
+    @earth_age = options[:earth_age]
+    @distance  = options[:distance]
+    @robots    = options[:robots]
+  end
+
+  def colonized?
+    @robots == true
+  end
+end
+
+
+earth = Planet.new(name: "Earth", mass: 32598234, robots: true)
+mars = Planet.new(name: "Earth", mass: 23455, robots: true)
+solar_system = SolarSystem.new(name: "Our solar system", planets: [earth, mars])
+
+venus = Planet.new(name: "Venus", mass: 2343284092384, robots: true)
+planet_dog_food = Planet.new(name: "Dog Food", mass 0, robots: false)
+
+solar_system.add_planet(venus)
+solar_system.add_planet(planet_dog_food)
+
+
+
+planets = {
+  "mercury" => Planet.new(),
+  "venus" => Planet.new()
+}
+choice = gets.chomp.downcase
+planets[choice]
+
+
+
+