From International Innovation- ” Life in the cosmos: Seth Shostak”

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International Innovation

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SETI Seth Shostak
Seth Shostak

What is it about astronomy that captivates you?

I find astronomy captivating, not only because it deals with huge and imposing celestial objects that have existed for billions of years, but it also answers big questions, questions that everybody, no matter where they live, might ask. Where did the Universe come from? Where is it going? What’s out there? For this reason, it’s a privilege to work in this field.

As the only organisation addressing the full range of disciplines investigating life in the Universe, what is the Search for Extraterrestrial Intelligence (SETI) Institute’s mission?

The Institute’s mission is to research life in the cosmos; it’s that simple. We’re not only looking for intelligent life forms – which is the purpose of the SETI experiments – we’re also looking for the existence of microbes closer to Earth, for example, on Mars or on some of the moons surrounding Saturn or Jupiter. There are more than half a dozen locations in our own solar system where life could exist, or where it could have once existed, with Mars being one of the favourites.

Our work also involves investigating how life started on Earth, because this could give us some indication of how it might have started elsewhere, as well as finding exoplanets – planets orbiting other stars – that are possible habitats for life.

When I joined the SETI Institute in 1991, the majority of its efforts were focused on radio SETI, which was by far its biggest project. However, today, 95 per cent of our scientists are working on what’s called astrobiology, looking for evidence of life on Mars, Jupiter, Saturn’s moons, etc. The Institute’s emphasis has greatly shifted.

Could you share examples of R&D projects that are currently underway at the SETI Institute?

In the astrobiology realm, there are around a dozen researchers studying the history of Mars. They are seeking to answer questions such as whatthe planet may have looked like 4 billion years ago and whether there was water on it. Today, Mars is cold and extremely dry – a terrible place for supporting life – but it wasn’t always so. The question is whether it could have supported life at one point. It’s certainly possible that we’ll find microbes there, so there is a lot of hardware roaming around the surface of Mars and orbiting the planet in an attempt to find out more about its history.

Other researchers here are studying asteroids and meteors to find out whether they brought ingredients for life to Earth. If this is the case, it’s possible the same has happened to other planets. Similarly, a group is researching Jupiter and Saturn’s moons for water, and consequently life. We also have a team working on the New Horizons mission, which has just flown by Pluto. In fact, one of our senior research scientists, Dr Mark Showalter, found two of Pluto’s moons.

Another important project for our astrobiologists is the search for exoplanets. We’re heavily involved with NASA’s Kepler Mission and that particular effort has found over 4,000 planets orbiting stars, some of which appear to be similar to Earth. We are also planning a large survey of dim stars, which are smaller than the Sun, because these might have habitable planets orbiting them. Finally, we’re making improvements to our equipment; for example, building new radio receivers.

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As part of a new trend in radio astronomy, the Allen Telescope Array (ATA) uses a large number of small dishes (LNSD) array to simultaneously survey numerous SETI targets. How does the ATA work and what are the key advantages of this approach?

The ATA uses 42 relatively small antennas, which are 20 feet in diameter. This differs from past approaches in that radio telescopes built in the 1960s and 1970s used the largest possible antennas. While bigger antennas are able to receive more cosmic static and fainter signals, they are far more expensive to build. Thanks to advances in electronics, however, it’s now possible to connect a lot of small antennas together to achieve the same performance as one big antenna, only for a lot less money. Not only that, but small antennas can scan large swathes of the sky much more quickly than large antennas.

Can you summarise the Institute’s most significant achievements to date?

Our planetary discoveries have certainly made the headlines. For example, the planet Kepler 452b is 1,400 light-years away and orbits a star that is just like the Sun. This planet could be Earth’s cousin in that it’s a little bit bigger than Earth and its year is 385 days long rather than 365 days. Another planet, which is similar in size to Jupiter, was found by one of our astronomers around a nearby star. This planet was found using a ground-based telescope, which isn’t usually possible.

Another significant achievement is the New Horizons mission. It took New Horizons almost ten years to arrive at Pluto, and the team working on this project didn’t know whether the spacecraft would actually make it or if there would be any data to collect at the end of its journey. It has been wonderfully successful, however, and we’ll be continuing to receive data for the next year and a half.

In terms of the ATA, we haven’t found a signal yet, but the speed of our search is continually increasing. I have bet everyone a Starbucks coffee that we’ll find ET within 20 years. I may have to buy a lot of coffee, but there’s hope!

What are the greatest challenges facing signal detection technology and how can the Center help to overcome these issues?

One of the biggest challenges we face is funding because this directly affects what we can achieve and the types of equipment we can develop. The astrobiologists benefit from NASA funding but all of the Institute’s SETI experiments are privately funded. There are a number of approaches we could adopt to speed up our research; for example, the technology developed for video games uses specialised hardware that can complete computational tasks very quickly. The technical challenges associated with doing this could certainly be solved. When I bet people a cup of Starbucks coffee that we’re going to find ET, this assumes that we can develop the equipment necessary to greatly speed up our work – and this is possible if we have the funds.

What more can be done to attract support from funding bodies and further engage the public?

We get a lot of media attention and the public is interested in what we do. Indeed, we even have the attention of the House Committee on Science, Space & Technology in congress, where I testified about a year ago. I would say the public is aware of what we’re doing but what they don’t know is that we can’t do very much because of funding issues. Communicating that message would enable us to have a decent chance of success; if we can build the right equipment we might be able to find ET.

Can you reveal what the future holds for the Institute?

I’m very optimistic about the future because this really is a special time in history. We know so much more about astronomy and the planets orbiting other stars than we did when I was a kid, or even twenty-odd years ago. Now we know what’s out there, we have the ability to build equipment that could, in principle, find proof of life, whether in our solar system or somewhere else in space. This is the first time we can say this.

I think the public recognises this at some level. Some people will have read about planets orbiting other stars or water on Mars, and it may occur to them that this could be the generation that finds extraterrestrial life. It’s rather like being alive at the end of the 15th Century when people were finally able to build wooden ships that could cross the ocean, and that rapidly changed the world as they knew it.

http://www.seti.org

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