12 items with the tag “mass extinctions

  • NAI Feature Stories

    Impact From the Deep

    October 19, 2006
  • Exobiology Feature Stories

    Sinking Life in Shallow Seas

    November 25, 2009
  • NAI Exobiology Research Highlights

    Timeline of a Mass Extinction

    November 18, 2011
  • Dynamical Effects on Planetary Habitability
    NAI 2010 VPL at University of Washington Annual Report

    VPL explored numerous features of orbits. We showed that comets are unlikely to have produced more than 1 mass extinction event in the past 500 million years. We catalogued the fractions of habitable zones of nearby stars that are capable of supporting a habitable planet. We also participated in the discovery of two planets whose orbital planes are offset by 30 degrees.

    ROADMAP OBJECTIVES: 1.1 1.2 4.3
  • Dynamical Effects on Planetary Habitability
    NAI 2011 VPL at University of Washington Annual Report

    The Earth’s orbit is near-circular and has changed little since its formation. The Earth is also far enough away from the Sun, that the Sun’s gravity doesn’t seriously affect the Earth’s shape. However, exoplanets have been found to have orbits that are elliptical, rather than circular, and that evolve over time, changing shape and/or moving closer or further to the parent star. Many exoplanets have also been found sufficiently close to the parent star that the star can deform the planet’s shape and transfer energy to the planet in a process called tidal heating. In this VPL task we investigate how interactions between a planet’s orbit, spin axis, and tidal heating can influence our understanding of what makes a planet habitable. Scientific highlights include the finding that tidal effects could be strong enough to cause a planet to overheat and ultimately lose its ocean, that large changes in the direction of the spin-axis of a planet could potentially increase the range of distances from the star in which the planet could remain habitable, and that the Sun may have moved significant distances outward through the Galaxy during its lifetime, changing the rate of at which large bodies have hit the Earth.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3
  • Dynamical Effects on Planetary Habitability
    NAI 2012 VPL at University of Washington Annual Report

    The Earth’s orbit is near-circular and has changed little since its formation. The Earth is also far enough away from the Sun, that the Sun’s gravity doesn’t seriously affect the Earth’s shape. However, exoplanets have been found to have orbits that are elliptical, rather than circular, and that evolve over time, changing shape and/or moving closer or further to the parent star. Many exoplanets have also been found sufficiently close to the parent star that it can deform the planet’s shape and transfer energy to the planet in a process called tidal heating. In this VPL task we investigate how interactions between a planet’s orbit, spin axis, and tidal heating can influence our understanding of what makes a planet habitable. Scientific highlights include modeling of habitable planets around brown dwarfs, the first comprehensive analysis of exomoon habitability, the role of distant stellar companions on planetary system architecture, and an improved understanding of the origins of terrestrial planet composition.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3