Objective Prism Extraterrestrial Laser Search

“It would be appropriate to examine high-resolution stellar spectra for lines which are unusually narrow, at peculiar frequencies or varying in intensity.”

– R.Schwartz and C.Townes 1961, Nature, 190, pg.205.

“Lasers can increase your data rate from Mars by 10 times over what you get from radio.”

– Suzanne Dodd,

JPL Director of Interplanetary Network Directorate

“One great advantage of optical SETI is that there’s no terrestrial interference.”

– Frank Drake.

“Optical Inter-Satellite Links are the essential building block for next generation commercial and government space networks.”

– Bulent Altan, CEO Mynaric

Searches for Laser Signals

  • We conduct surveys for non-natural light emission coming from the Solar System and the Milky Way Galaxy.
  • We design wide-field optical techniques including Schmidt telescopes, objective prisms, and huge high-speed cameras. We capture wavelengths of light from 320-950 nm across a 2-degree field of view.
  • Our optical systems are particularly sensitive to laser communication, easily distinguished from continuous spectra produced by asteroids, planets, stars, and other astrophysical sources. Simultaneous observations with a second telescope provide confirmation.
Video of a real-time search for unidentified light emission.
The Pleiades star cluster observed with the SLA objective prism telescope system. Each horizontal streak is the spectrum of a star, including wavelengths 360nm to 1000 nm (left to right; blue to red). Laser emission would appear as a “dot” of one wavelength,  validated by appearing in both telescopes at the same point in the sky and the same instant of time within 0.25 seconds.
Video clip of real-time acquisition of objective prism spectra from both telescopes simultaneously, at four frames per second. Field of view is 2deg x 2deg. Laser pulses would appear as a “dot” from both telescopes simultaneously.
Video clip of real-time acquisition of objective prism spectra from both telescopes simultaneously, at four frames per second. Field of view is 2deg x 2deg. Laser pulses would appear as a “dot” from both telescopes simultaneously.
Space Laser Awareness technology can detect, track, and obtain spectra of satellites in real time.
Satellites passing within the field of view are detected instantly by their motion. The direction and angular speed of their motion are measurable. LEO, MEO, and GEO satellites are distinguished.
The spectrum of the object is simultaneously acquired with a resolution of lambda/delta-lambda = 100 in each frame. 
The Solar Gravitational Lens region of Alpha Centauri.  Field of view is 2deg x 2.5 deg, in a 4 minute exposure with 0.28-meter objective prism Schmidt telescope.  The hundreds of vertical streaks are stellar spectra. A laser will show as a PSF-shaped dot.

 

Real-time video of Saturn (below) and Jupiter (above), when a satellite passes.
One field station of SLA, with Sagittarius (left), Scorpio (right). The two brightest objects are Saturn (upper left) and Jupiter (upper right).

 

An artist rendering of communication lasers in the Milky Way Galaxy.

 

 Proxima Centauri: A search for lasers. 

Top: No flare. Middle: a medium-level flare. Bottom: a super-flare on Proxima Centauri. Laser emission will appear as emission not associated with flares.  Spectra are courtesy of the public ESO data archive.

The spectrum of Vega vs wavelength obtained with the objective prism telescope and QHY600 camera.

 

The spectrum of the planetary nebula, NGC7027, vs. pixels with the objective prism telescope and the QHY600 camera.  H-alpha and [OIII] are separated by 300 pixels