Looking for life on Mars

The search for intelligent alien life by PC users around the world will be getting an upgrade. The overhaul, due in about a month, is an addition to a screensaver that scans radio signals from space for signs of alien life.

The project, which was launched in May and run at the University of California at Berkeley, is called Search for Extraterrestrial Intelligence, SETI@Home. Pilot versions are now being tested.

The masterminds behind the device are a group of astronomers and engineers who are attached to a SETI project called Serendip (Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations).

The idea behind SETI@Home is to take advantage of the unused processing cycles of personal computers. An interested computer owner will download free software from SETI@Home. Then, when their computer is idle, this software will download a chunk of Serendip data for analysis.

The results of this analysis are ultimately sent back to the Serendip team, combined with the crunched data from the thousands of other SETI@Home participants, and used to help in the search for extraterrestrial signals.

A $50,000 donation to the program came from Paramount Pictures and the private Planetary Society is also providing funds. Sun Microsystems has donated free computer equipment. Additional sponsors include Fuji Film, IBM developerWorks, Quantum, Intel and Informix.

Power computing
Scientists at the university have 1.6 million users, more than 500,000 of whom are active at any time. According to Eric Korpela, an assistant at SETI@Home, the project uses the world's most powerful computer, providing more than eight teraflops of processing per day.

"We have a little more than 1.6 million users who have downloaded the software and ran it at least once," Korpela said. "Today we have 443,000 active users scattered all over the place. Right now the US is the biggest user and the European countries are the next largest contributors."

Korpela said they are in beta test right now with the new release and "assuming all goes well, it could be ready in about three or four weeks from now."

"We are very pleased with how things are going, but there was quite a long time when the computers couldn't handle the number of users. But through generous donations from hardware vendors such as Sun Microsystems, which upgraded the servers, we can handle everything," he said.

Signal failure
Korpela pointed out that right now the study has 185 million candidate (possible) signals, "although the vast majority of those are going to be obvious interference. We will crunch through the signals we have and apply the techniques to them. But the going is slow when there are 185 million signals involved."

The program includes going through some automated routines to find obvious signals from earth, and then taking a closer look. "We will take a look at the really good candidates and hopefully see radio emissions from another planet," he said.

SETI@Home has been gathering raw data since October 1998 from the Arecibo radio telescope in Puerto Rico, the world's largest radio telescope. There is also a SETI experiment in Australia, located in the Faculty of Informatics, Science and Technology at the Campbelltown campus of the University of Western Sydney Macarthur.

Australia's project piggybacks onto normal radio astronomy observations at CSIRO's 64-metre Parkes radio telescope. The technology was developed at the Space Sciences Lab by the Serendip group at the University of California Berkeley.

Changes to the system
There have been a few major changes in SETI@Home 2.0. The first is comprehensive firewall support which replaces the current release 1.06 which had only minimal firewall support. Another change is protecting the results file.

With version 1.06 results were saved in a basic text file, so anyone could modify them to get their name in the top-20 high performers. Some new processing code to the program has also been added.

"The universe is teeming with life," said Dan Werthimer, a professor at Berkeley's Space Sciences Laboratory. "It's like tuning your FM dial, but you have to search billions of channels at once."

Werthimer is optimistic that something will be found in his lifetime. But he cautioned if and when a signal is detected and decoded, it is unlikely that "we will ever meet ET face-to-whatever because of the distance between us.

"I don't think we will ever visit them or they will visit us," he said.

Broadcast news
Werthimer said that the Earth has been broadcasting to the universe for about 40 years. Though radio communications are more than 100 years old, only longer-wave signals such as television have gone beyond the Earth's atmosphere. "The Earth is brighter than the sun in the radio spectrum," he said.

In two years' time, the program will scan all the sky visible from Arecibo three times over. "We find this very exciting. With as many machines looking as we have, you can basically sift through as much as you want to. We were never able to do this before," Korpela said.