Regional Jet 200 ER/LR (CRJ200)
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Situational Awareness
Conflict NMAC
General None Reported / Taken
Procedure; Aircraft; Airspace Structure
Near miss with drone while on arrival into O'Hare. Weather: Clear and calm; winds were out of east at 4 kts.  O'Hare was landing to the east; we were assigned to Runway 10R ILS Y with a Visual Approach.  On arrival we were at 10;000 feet and level at 300 kts on the arrival course.  Note attached Chicago TAC chart showing approximate location marked with a Red Star.  I believe we were on the VEEK4 Arrival.  Completely uneventful flight up to this point.  I was admiring the view of downtown Chicago on a nice VFR summer day from the Copilot's seat.  The cockpit was sterile.  Suddenly; from my right side window divider post; I spotted an object traveling at an incredible rate of speed opposite our flight path.  As my eyes fixated on the object; I realized I was looking at a commercial sized drone; quad-copter; grey in color.  It had a camera mount under its base. I had visual contact with the drone for approximately 1.5 to 2 seconds before it vanished behind our right wing tip and out of view.  The drone was exactly level with our altitude; 10;000 feet.  I estimated the drone to be 100 feet from our aircraft. My immediate action and due to my increased heart rate was shouting 'Holy ____!' on the intercom to alert my Captain.  He looked stunned at me and asked; 'What?' I explained to him exactly what I saw as described above.  My Captain stated he did not see it; but was not looking that way.  I doubted myself momentarily; but the near miss replayed itself in my mind.  I believe this drone operator was taking advantage of a clear day unaware of the airspace rules or purposely violating the rules to get a clear image/photograph of the entire city of downtown.  It was perfectly positioned for a shot of the city given the sun position and time of day.  Had the drone impacted our aircraft; I fear to think about what the results may have been; whether it hit our wing root; ingested into an engine; or penetrated a cockpit window.  My Captain alerted ATC and an advisory broadcast was made by Chicago Approach.  I heard no further information or feedback from ATC or the FAA once on the ground.  Suggest greater crackdowns on drone operations need to exist.  Or drone manufacturers and operators must have TCAS reporting capability/ADS-B systems included as a mandatory requirement.  I fly a drone myself; a hobby drone.  I am also hold a UAV Drone Certificate.  However; I can see someone clearly and eventually using a drone for malicious reasons if they so desired.  Ultimately; I am still surprised that a drone would be capable of a 10;000 foot operation from this experience; but after doing a quick Google search; I see commercial drones are not authorized to; but are capable of altitudes of 11;000 feet or higher.
CRJ First Officer reported a near mid-air with a drone while level at 10;000 feet on arrival into O'Hare.