SearchLites - Vol 03 No 4

Magazine Overview

SearchLites, Volume 3, Number 4, Autumn 1997, is the quarterly newsletter of The SETI League, Inc. It is a membership-supported, nonprofit, educational, and scientific corporation dedicated to the electromagnetic Search for Extra-Terrestrial Intelligence. The issue is copyrighted 1997 by The SETI League, Inc.

Introduction: The SETI League's Secretary

This section introduces Heather Wood, who has been appointed Secretary of The SETI League. H. Paul Shuch, the Executive Director, describes Wood as a British subject residing in the US, who has been with the organization since its inception. She is credited with folding, stapling, and mutilating the newsletter. Wood has a diverse background, including a career in folk music with the group 'Young Tradition,' followed by roles in food service, military service, writing, publishing, music recording, computers, electronics manufacturing, and banking. Shuch notes her 'anentropic' nature, which brings order to the office, and humorously takes responsibility for any inaccuracies in the newsletter.

Conference Calendar

The newsletter provides a calendar of upcoming conferences where SETI-related information will be presented. Readers are encouraged to check the SETI League's website (www.setileague.org) or email [email protected] for details. Members are also invited to submit information about other relevant events. The calendar lists events from September 1997 through May 2000, including amateur radio exhibitions, astronomy congresses, space symposiums, and various SETI conferences, such as the 'International Conference on SETI in the 21st Century' in Sydney, Australia.

Ask Dr. SETI

This column addresses a reader's question about fundamental problems with our perceptions of what should be detectable in SETI. The reader suggests that technical considerations might be secondary to other, unknown reasons why ET radio waves are not being detected. They propose studying lightning-generated radio waves as a potential unique signal. Dr. SETI responds by acknowledging the premise but states that there is no clear evidence that these waves are not getting here, only that they haven't been received in a verifiable way. He mentions Paul Ryan's extensive work on lightning spectrum analysis and the development of the Storm Scope, noting that lightning's energy peaks at 50 kHz, which is largely blocked by the ionosphere. Space-based searches are deemed too expensive. Dr. SETI confirms that SETI receivers have been tested against known natural and artificial signals, such as those from extra-solar radio sources, the Pioneer 10 spacecraft, and the Global Mars Surveyor satellite, demonstrating their adequate sensitivity. The column concludes by stating that while a few thousand hours of observation have been logged, this is a tiny fraction of the sky and frequencies, leaving the vast majority unexplored.

Participatory SETI: A Model for Public Involvement

This section presents an abstract for an invited paper by H. Paul Shuch, SETI League executive director, to be presented at the 'SETI in the 21st Century Conference' in Sydney, Australia. The paper addresses the public perception that SETI requires facilities only governments can afford, a view reinforced by the cancellation of the NASA SETI program. It argues that advances in technology have made SETI equipment accessible to amateurs. The paper explores educational initiatives by The SETI League to foster more realistic public perceptions of SETI requirements and costs, estimating the equipment and coordination costs for a global search effort. It suggests that the public underestimates the true costs and benefits of a large-scale SETI program.

Correspondence

This section features a collection of letters and emails from SETI League members congratulating H. Paul Shuch on his new five-year contract as Executive Director. Readers express delight and support for his continued leadership, acknowledging the commitment and importance of his work for SETI.

Technical Feature: Searching for Habitable Planets

Authored by Ron Blue and Woody Lakey, this article proposes using radio emissions from lightning storms in extraterrestrial atmospheres (oxygenated or Jovian) as a means to detect planets. The abstract notes that while calculations suggest life on other planets is mathematically probable, empirical evidence is lacking. The article discusses advances in planet detection, such as observing stellar wobbles and analyzing pulsar signals, and mentions evidence from the Hubble Space Telescope. It emphasizes the need for caution in interpreting findings. The authors suggest that lightning signals could be unique and detectable, especially if they occur in oxygenated atmospheres, similar to Earth's. They propose using radio telescopes, potentially with enhanced configurations or 'super antennas,' to detect these signals. The article also touches upon the rarity of Jovian-type planets, which are considered important for sweeping solar systems of comets and thus enabling the development of stable life systems. It contrasts this proposed method with traditional SETI searches for artificial signals and discusses the limitations of current technology and the vastness of time scales involved in detecting signals from civilizations at different technological stages.

Page 4 Discussion

The discussion continues on the possibility of detecting planets via lightning. It reiterates that all planets in the solar system are suspected of having lightning, with observed instances on Venus, Jupiter, Mars, Uranus, and Neptune. The unique radio signal produced by lightning is dependent on the atmosphere. Jupiter's lightning occurs at 10 MHz, and detecting a similar signal from an exoplanet could indicate a similar atmosphere. The article notes that while current technology might find it unlikely to detect such signals, science should remain open. It suggests that using Earth or other planets as shields against local noise might improve detection chances. The article emphasizes that Earth's oxygenated atmosphere, created by photosynthesis, is unique in our solar system and that lightning storms have been a constant signal of life on Earth for billions of years. It contrasts this with traditional SETI searches for patterned signals like radio or TV broadcasts, noting that our own signals are only 100 light-years away. The article suggests that detecting lightning signals could help locate planets for future SETI monitoring and that even if SETI doesn't yield direct contact, knowing the location of other Earth-type planets would be valuable. It also acknowledges the difficulties, including the need for advanced observatories (lunar, Earth orbit, or solar orbit) and the problem of local radio noise, especially from terrestrial lightning.

Page 5 Discussion Continued

The discussion on detecting exoplanets via lightning continues. It highlights that lightning signals only occur in oxygenated atmospheres and that while other phenomena might emit similar frequencies, lightning occurs in sets. A single lightning bolt can be tracked globally, suggesting that lightning from other oxygenated atmospheres could also be tracked from Earth, the moon, or outer space. The process is acknowledged as difficult, with potential for human error and the need to ensure signals originate from deep space. Using multiple, computer-linked monitoring stations is proposed to validate signals. The article details requirements for antennae (minimum thirty-five feet high, seventeen and one half feet long) and their spacing (at least four thousand meters apart). It suggests focusing reflected radio waves onto a liquid helium-cooled superconductor to amplify weak signals. The concept of a 'super antenna' is introduced to attract and differentiate spurious signals. The potential for recognizing extraterrestrial Earth-type, Jupiter-type, Venus-type, or Mars-type planets is mentioned. The article notes that lightning storms on Jupiter occur frequently at noon, and a similar signal pattern from an exoplanet could indicate its rotation period. It also suggests that the frequency and location of lightning storms on planets with oxygenated atmospheres could reveal water-land distributions, aiding in mapping Earth-type planets. The authors speculate that intelligent life might be listening for these natural frequencies for communication, rather than the 21-centimeter hydrogen line, due to the high 'admission price' to galactic civilization.

Back Cover Information

The back cover provides details about The SETI League, Inc., including its mission, contact information (address, phone, fax, email, website), and copyright notice. It also features a form for accepting credit cards (Visa/MasterCard) for membership dues and additional contributions. A list of membership levels and their associated costs is provided, ranging from Household Member ($15) to Benefactor ($1,000,000). Additionally, a list of 'Additional Contributions' with corresponding 'Membership Premiums' is offered, including items like T-shirts, coffee mugs, mouse pads, pocket protectors, buttons, technical manuals, and songbooks.

Recurring Themes and Editorial Stance

The recurring themes in this issue of SearchLites are the ongoing efforts and challenges in the Search for Extra-Terrestrial Intelligence (SETI), the exploration of new methods for detecting exoplanets (specifically using natural phenomena like lightning), and the importance of public involvement and support for SETI initiatives. The SETI League positions itself as a key organization facilitating these efforts, particularly through its membership-supported model and its focus on both traditional SETI and innovative approaches. The editorial stance appears to be one of persistent exploration, scientific rigor, and a belief in the potential for amateur participation in advancing the field of SETI.