Giant Telescope To Seek Habitable Planets in Alpha Centauri

A stronomers at the European Southern Observatory say they will use one of their high-powered tools to search for inhabitable planets near Earth.

The announcement this week came as part of a partnership with the Breakthrough Initiatives, a group that describes itself as "a program of scientific and technological exploration, probing the big questions of life in the universe: Are we alone? Are there habitable worlds in our galactic neighborhood? Can we make the great leap to the stars?"

To help answer those questions, the two have teamed up for a multipronged project to visit Alpha Centauri that will last years. As a first step, the ESO will try to identify how many and what kinds of planets may be out in our stellar neighborhood.

Beginning in 2019 the ESO's Very Large Telescope in Chile will begin taking a very close look at the Alpha Centauri star system. At about 4.3 light-years away, it is the closest system to the Earth and made news last year when astronomers discovered an Earth-like planet, Proxima B, floating around Proxima Centauri, one of the three stars in the system. The other two stars in the system are a binary pair, named Alpha Centauri A (also named Rigil Kentaurus) and Alpha Centauri B. These two spin around each other every 79 years, separated by about the same distance as our sun and Pluto.

Among these three stars there's the potential for lots of other planets, so the agreement will provide funding to pay for some modifications to the ESO's VISIR (VLT Imager and Spectrometer for mid-Infrared) instrument. The changes will provide a new set of glasses that should make it easier for VISIR to spot any other potentially inhabitable planets in the system. The agreement also provides for telescope time, which is expensive, to allow a careful search beginning in 2019.

A big part of the Breakthrough Initiative is a program to send tiny probes to visit newly found, potentially inhabitable planets. It sounds crazy, but physicists like Stephen Hawking say the project is feasible potentially within this generation.

Fleet of Space Probes

The program, Starshot, is based on technology that still has to be developed, but it involves sending hundreds, maybe thousands of tiny space probes to Alpha Centauri, with an arrival time of about 20 years. Each tiny probe would be equipped with a full array of instrumentation, including communications equipment, a camera and a nuclear battery. The team says that with continuing advances in miniaturization technology, all that "stuff" should soon be small enough to sit on a probe that weighs about a gram and is the size of a postage stamp.

Each probe will be attached to a solar sail that will get a push from a high-altitude laser, which will accelerate the probes to about 20 percent the speed of light. That's far faster than we've ever gone, but scientists at the Breakthrough Initiative say there's no reason it won't work - it's just that no one has done it yet.

Don't expect the Starshot initiative to get off the ground for another 30 to 40 years. But even if some snags slow down the project, one thing is certain: The ESO is going to be taking a really close look at our neighbors' stars before 2020, and that should give us a much better idea of how many more planets there are right next door.

It should also give scientists more information to go on as they estimate how many inhabitable planets there are in our galaxy, a number that continues to climb based on information astronomers have been collecting for the past two decades.