Join Donate

Optical SETI

Are We Alone? We built the world's first OSETI Telescope dedicated to finding out.

Whatever form an alien signal might take -- the faintest radio transmission, or a split-second pulse of light -- The Planetary Society is committed to discovering it. You can help us keep watch.

In 2006, The Planetary Society unveiled the first All-Sky Optical SETI (OSETI) telescope. Funded by The Planetary Society and operated by a Harvard University team, it's completely dedicated to capturing that one pulse of light that might be a communication. Over the years, our members have helped upgrade and improve the hardware for this program, searching the skies and processing enormous amounts of data.

With its 72-inch primary mirror, the OSETI Telescope is not only the only largest telescope in North America devoted to SETI; it is also the largest optical telescope in the U.S. east of the Mississippi. And, with cutting-edge processors, in just one second, it crunches more data than what is stored in all books in print.

OSETI Telescope Primary MIrror

Paul Horowitz

OSETI Telescope Primary MIrror
Construction of Planetary Society's Optical SETI telelscope in Oak Ridge, Massachusetts. Graduate student Jason Gallicchio is seen here reflected in the 1.8 meter primary mirror.

To date, the Optical SETI Telescope has completed over a thousand sets of observations. It takes 200 clear nights to cover the entire sky once and complete a snapshot. Then it starts again. Although dozens of triggers (pulses) have so far been sighted, all have been ruled out as communications. But vigilance is key: one signal from light-years away could prove we're not alone in the vastness of space -- and alter humanity's view of our place in the universe.

We're keeping close watch -- and making great strides -- but there is much more work to be done. We are in the process of installing amplifier boards to double the sensitivity of the OSETI Telescope. We are also working to completely automate the telescope to capture continuous data every possible minute of every night.

Visible light is thought to be a likely form of interstellar communication because visible light travels easily through space and suffers little interference. A tightly focused light beam, such as a laser, can be 10 times as bright as the Sun and be easily observed from enormous distances. Laser-like light signals are also unidirectional, making it possible to determine their source with great precision, and -- because of their higher frequencies -- can be used to send vast amounts of information.

But in order to receive a light signal from an alien civilization, we must be looking for it. With the Society's dedicated Optical SETI Telescope, our eyes are open.

Since its founding, The Planetary Society has been a leading advocate of the Search for Extraterrestrial Intelligence, supporting a wide variety of searches, making use of different approaches. Most of these -- and the largest ones -- have been radio SETI projects such as BETA, SERENDIP, [email protected], and Southern SETI. Now, after decades of listening, The Planetary Society has turned its eyes to the skies to scan for possible light signals.

We don't know what we'll find. But we do know we'll find nothing if we don't keep searching.

Keep us searching. Donate to our Optical SETI project here >>

Project Updates

Reobservations Report No. 6: Solar Intervention Postpones [email protected] Reobservations

[email protected]'s plans to reobserve its most promising candidate signals were interrupted today by the unexpected intervention of a Solar flare.

Reobservations Report No. 5: First Observation Session Completed at Arecibo

The [email protected] team has completed the first of its three 8-hour observation session at Arecibo, designed to revisit the most promising candidate signals detected so far by [email protected]

Reobservations Report No. 4: Results in Real Time

[email protected] scientists will have to wait for several weeks for the full analysis of the data collected during the reobservations. But even while the observations are going on at Arecibo, they will already have a good idea if they have found something significant.

Reobservations Report No. 3: Selecting the Finalist Candidates

For three successive days [email protected] will have use of the giant Arecibo radio telescope to revisit the most promising candidate signals detected since the project was launched in 1999. [email protected] Chief Scientist Dan Werthimer and his team put together a list of the "best" 200 locations in the sky where promising candidates have previously been detected.

Reobservations Report No. 2: Reobserving, Recording, and Reprocessing

For the first time during the reobservations, Werthimer and his crew will have use of another recorder. This is Arecibo's "radar" recorder, built for those occasions when the giant dish is used as a radar, bouncing electromagnetic signals off planets, moons, and asteroids.

Reobservations Report No. 1: Shifting Gears at Arecibo

In the next few days, [email protected] Chief Scientist Dan Werthimer, along with team members Eric Korpela and Paul Demorest, will head down to Arecibo in Puerto Rico. There, at the site of the largest radio telescope in the world, they will begin a new chapter in the short history of the project: the reobservation of [email protected]'s most promising candidate signals.

[email protected] Listens to the Dying Gasps of Black Hole

If we were to listen to radio transmissions from space, we should be able to hear the dying gasps of black holes. As it turns out, we are listening, or at least the [email protected] receiver is. Perched above the giant Arecibo dish, it is systematically surveying a large portion of the sky, listening to the signals coming from space.

Items 41 - 47 of 47  Previous12345
astronaut on Phobos
Let's Change the World

Become a member of The Planetary Society and together we will create the future of space exploration.

Join Today

The Planetary Fund

Help advance robotic and human space exploration, defend our planet, and search for life.


You are here: