Best way to create instance of child object from parent object

The base class needs to define a copy constructor:

public class MyObject
{
    protected MyObject(MyObject other)
    {
        this.Prop1=other.Prop1;
        this.Prop2=other.Prop2;
    }

    public object Prop1 { get; set; }
    public object Prop2 { get; set; }
}

public class MyObjectSearch : MyObject
{

    public double Distance { get; set; }

    public MyObjectSearch(MyObject obj)
         : base(obj)
    {
        this.Distance=0;
    }
    public MyObjectSearch(MyObjectSearch other)
         : base(other)
    {
        this.Distance=other.Distance;
    }
}

This way the setting of properties is handled for all derived classes by the base class.