Design World

  • Home
  • Technologies
    • 3D CAD
    • Electronics • electrical
    • Fastening & Joining
    • Factory automation
    • Linear Motion
    • Motion Control
    • Test & Measurement
    • Sensors
    • Fluid power
  • Learn
    • Ebooks / Tech Tips
    • Engineering Week
    • Future of Design Engineering
    • MC² Motion Control Classrooms
    • Podcasts
    • Videos
    • Webinars
  • LEAP AWARDS
  • Leadership
    • 2022 Voting
    • 2021 Winners
  • Design Guide Library
  • Resources
    • Subscribe!
    • 3D Cad Models
      • PARTsolutions
      • TraceParts
    • Digital Issues
      • Design World
      • EE World
    • Women in Engineering
  • Supplier Listings

Life or Illusion? Avoiding ‘False Positives’ In The Search For Living Worlds

By University of Washington | March 1, 2016

Share

Research from the University of Washington-based Virtual Planetary Laboratory published Feb. 26 in Astrophysical Journal Letters will help astronomers better identify — and thus rule out — “false positives” in the search for life beyond Earth.

Powerful future devices such as the James Webb Space Telescope, set for launch in 2018, may help astronomers look for life on a handful of faraway worlds by searching for, among other things, evidence of oxygen — a “biosignature” — in their atmospheres. This is done by transit spectroscopy, or studying the spectral features of light visible through a planet’s atmosphere when it transits or passes in front of its host star.

“We wanted to determine if there was something we could observe that gave away these ‘false positive’ cases among exoplanets,” said lead author Edward Schwieterman, a doctoral student in astronomy. “We call them ‘biosignature impostors’ in the paper.

“The potential discovery of life beyond our solar system is of such a huge magnitude and consequence, we really need to be sure we’ve got it right — that when we interpret the light from these exoplanets we know exactly what we’re looking for, and what could fool us.”

Here on Earth, oxygen is produced almost exclusively by photosynthesis — plants and algae converting the sun’s rays into energy to sustain life. And so Earth’s oxygen biosignature is indeed evidence of life. But that may not be universally true.

Previous research from the Virtual Planetary Laboratory has found that some worlds can create oxygen “abiotically,” or by nonliving means. This is more likely in the case of planets orbiting low-mass stars, which are smaller and dimmer than our sun and the most common in the universe.

The first abiotic method they identified results when the star’s ultraviolet light splits apart carbon dioxide (CO2) molecules, freeing some of the oxygen atoms to form into O2, the kind of oxygen present in Earth’s atmosphere.

The giveaway that this particular oxygen biosignature might not indicate life came when the researchers, through computer modeling, found that the process produces not only oxygen but also significant and potentially detectable amounts of carbon monoxide. “So if we saw carbon dioxide and carbon monoxide together in the atmosphere of a rocky planet, we would know to be very suspicious that future oxygen detections would mean life,” Schwieterman said.

The team also found an indicator for abiotic oxygen resulting from starlight similarly breaking down atmospheric water, H2O, allowing hydrogen to escape and leaving vast quantities of oxygen — far more than the Earth has ever had in its atmosphere.

In such cases, Schwieterman said, oxygen molecules collide with each other frequently, producing short-lived pairs of oxygen molecules that become O4 molecules, with their own unique signature.

“Certain O4 features are potentially detectable in transit spectroscopy, and many more could be seen in reflected light,” Schwieterman said. “Seeing a large O4 signature could tip you off that this atmosphere has far too much oxygen to be biologically produced.”

“With these strategies in hand, we can more quickly move on to more promising targets that may have true oxygen biosignatures,” he said.

“It’s one thing to detect a biosignature gas, but another thing to be able to interpret what you are looking at, said Victoria Meadows, UW professor of astronomy and principal investigator of the Virtual Planetary Laboratory. “This research is important because biosignature impostors may be more common for planets orbiting low-mass stars, which will be the first places we look for life outside our solar system in the coming decade.”

Source: http://www.eurekalert.org/pub_releases/2016-02/uow-loi022916.php


Filed Under: Aerospace + defense

 

Related Articles Read More >

Mars helicopter receives Collier Trophy
Flexible rotary shafts to power Delta Airlines’ engines powering their first Airbus A321neo aircraft
Ontic acquires Servotek and Westcon product lines from Marsh Bellofram
Flexible rotary shafts support thrust reverser on 150 LEAP 1-A turbofan engines

DESIGN GUIDE LIBRARY

“motion

Enews Sign Up

Motion Control Classroom

Design World Digital Edition

cover

Browse the most current issue of Design World and back issues in an easy to use high quality format. Clip, share and download with the leading design engineering magazine today.

EDABoard the Forum for Electronics

Top global problem solving EE forum covering Microcontrollers, DSP, Networking, Analog and Digital Design, RF, Power Electronics, PCB Routing and much more

EDABoard: Forum for electronics

Sponsored Content

  • Industrial disc pack couplings
  • Pushing performance: Adding functionality to terminal blocks
  • Get to Know Würth Industrial Division
  • Renishaw next-generation FORTiS™ enclosed linear encoders offer enhanced metrology and reliability for machine tools
  • WAGO’s smartDESIGNER Online Provides Seamless Progression for Projects
  • Epoxy Certified for UL 1203 Standard

Design World Podcasts

July 26, 2022
Tech Tuesdays: Sorbothane marks 40 years of shock and vibration innovation
See More >
Engineering Exchange

The Engineering Exchange is a global educational networking community for engineers.

Connect, share, and learn today »

Design World
  • Advertising
  • About us
  • Contact
  • Manage your Design World Subscription
  • Subscribe
  • Design World Digital Network
  • Engineering White Papers
  • LEAP AWARDS

Copyright © 2022 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search Design World

  • Home
  • Technologies
    • 3D CAD
    • Electronics • electrical
    • Fastening & Joining
    • Factory automation
    • Linear Motion
    • Motion Control
    • Test & Measurement
    • Sensors
    • Fluid power
  • Learn
    • Ebooks / Tech Tips
    • Engineering Week
    • Future of Design Engineering
    • MC² Motion Control Classrooms
    • Podcasts
    • Videos
    • Webinars
  • LEAP AWARDS
  • Leadership
    • 2022 Voting
    • 2021 Winners
  • Design Guide Library
  • Resources
    • Subscribe!
    • 3D Cad Models
      • PARTsolutions
      • TraceParts
    • Digital Issues
      • Design World
      • EE World
    • Women in Engineering
  • Supplier Listings