"Some kind of tracker. It's been modified."
Amanda Ripley, upon acquiring a Motion Tracker

The Motion Tracker that was used by Amanda Ripley.[1]

The Motion Tracker,[2][3][4] also known as a motion detector,[5] was an American electronic motion sensing device manufactured by Arious. It was used by Amanda Ripley aboard Sevastopol Station in 2137.


When motion was detected in front of the Motion Tracker, a circle would appear on its screen, indicating where the motion was detected. If motion was detected on the left, right or back of the Tracker, a crescent-like indicator would illuminate, indicating on which side of the Tracker the motion was detected.

The Tracker was prone to interference in enclosed spaces; in such situations, its screen tended to flicker, making it harder to determine the exact location of any moving targets. However, the Tracker's fundamental functions were unaffected and continued to work normally.

Unlike the tracking devices used by the crew of the USCSS Nostromo (including Amanda's mother, Ellen Ripley),[6] the Motion Tracker was relatively small (possibly even smaller than the M314 Motion Tracker used by the United States Colonial Marine Corps in 2179) and able to easily be carried in one hand.

In game[]

The motion tracker is very sensitive and detects movement through walls and other obstructions. If used inside a vent the motion tracker will glitch and show a less reliable view of movement in the vicinity. However, in the game's hardest difficulty, Nightmare Mode, the tracker frequently crashes and has fatal errors making it hard to determine where the displayed motion is coming from.

Behind the scenes[]

As a reference to the tracking device prop in Alien using an ice cube tray as a greeble,[7] the Motion Tracker also incorporates an ice cube tray-like detail on its right side. More nods to the tracker seen in the first film include the forward-facing "probe" behind the screen, which is remarkably similar to (albeit far smaller than) the probe that extended from the front of the tracker used in the movie and the red lines, letters and numbers that surround the screen, which are similar to the ones present around the grid on the film's tracker.

Although the game is mainly based on Alien, the Motion Tracker appears to also take inspiration from the Motion Trackers used in Aliens — the display is clearly based on the Aliens Motion Tracker's, the color is similar (the Motion Tracker props were "Brown Bess", but they appear green in the film due to lighting), and the size is also similar.

Improvise MT model

The model used in "Improvise".[8]

In the CGI trailer "Improvise" seen at Gamescom 2014, the Motion Tracker differs heavily from its in-game appearance. The Tracker in the trailer was designed by Maciej Kuciara, who notably incorporated a Hama self-timer in the design of the tracker,[8] which is another reference to the Motion Tracker used in Aliens.[9]

Additionally, the Motion Tracker in the trailer is supposed to look like it was assembled by Ripley from scrap parts[8] (as demonstrated at the end of the trailer when Ripley makes the screen of the tracker by taking one from a toy robot), but, in the game, advertisements for the Tracker indicate that it's actually a commercial product, used specifically for tracking vermin (although Ripley's is modified).