Finding Oxygen On An Alien World Does Not Always Mean There Is Life ThereWe now know the universe is filled with planets. By one estimate, there are more than 20 billion Earth-like worlds in our galaxy alone. But how many of them are likely to have life? And how would we know if they do? Unless they happen to send us a very clear message directly, the most likely way we’ll discover exoplanet life is by looking at their atmospheres.We have already detected atmospheres around a few large exoplanets, and when the James Webb Telescope is launched we should be able to study the atmospheres of Earth-sized exoplanets. But what would we need to see to confirm the presence of life?
Terrestrial life depends on a thin layer of oxygen-rich air. Credit: NASA
WASHINGTON — Raytheon received a $228 million contract to continue development of a ground system for Global Positioning System (GPS) satellites, the Space Force’s Space and Missile Systems Center announced April 30.
GPS 3 satellite rendition. Credit: Lockheed Martin