Podcaster: Dr. Al Grauer


Title: Travelers in the Night 161E & 162E: An Earth Like Planet & Fascinating Europa

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • Kepler-452b is orbiting a star very similar to our Sun at a distance that would allow for the possibility of liquid water on its surface.
  • You can spot Europa with almost any small telescope as a moving point of light orbiting the planet Jupiter just like Galileo Galilei did 400 years ago.

Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona.  This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.

He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.

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161E: An Earth Like Planet

Since the dawn of our race, it is likely that humans have looked into the night sky and wondered if they are alone in the Universe on a unique planet.

The NASA Kepler spacecraft has discovered more than a thousand planets orbiting distant stars. Very recently this effort has revealed a planet, called Kepler-452b, to be orbiting a star very similar to our Sun at a distance that would allow for the possibility of liquid water on its surface. Additional observations by Earth bound telescopes in Texas, Arizona, and Hawaii have proved to be vital in determining the temperature and age of Kepler-452b’s star. Computer models of how solar systems form suggest that this newly discovered planet could have a rocky surface  At Kepler-452b’s distance of more than 1,400 light years, it is a challenge to develop the techniques to measure this Earth like planet’s mass and atmospheric composition. The NASA James Webb Space Telescope which is scheduled to be launched in this decade is a powerful step in that direction.

Kepler-452b has spent 6 billion years in the habitable zone of its star. In the 4.5 billion years of the Earth’s history the parade of more than 5 billion species has included single cell organisms, various multi cellular life forms, land plants, dinosaurs, mammals, birds, flowers, and humans to name a few. It is mind blowing to consider what kind of life forms might exist on a planet which is 1.5 billion years older than mother Earth.

162E: Fascinating Europa

You can spot Europa with almost any small telescope as a moving point of light orbiting the planet Jupiter just like Galileo Galilei did 400 years ago. Of the 4 moons which you will see Europa is the one second closest to Jupiter.  

As Europa orbits the giant planet Jupiter on an elliptical path, it is stretched and flexed by tidal forces which heat its interior.  This continuous flexing heats Europa in a way which is similar to the way that automobile tires are heated as your car rolls down the highway.  The effect on Europa is so strong that it likely creates volcanic activity in the rocky layers far below its icy surface.  Measurements made by passing spacecraft strongly suggest that Europa has a salty ocean, covered by a thick layer of ice, which may contain more water than all of the Earth’s oceans put together.   A sighting by the Hubble Space Telescope of plumes of water erupting from Europa give a further indication of the possibility of a subsurface ocean on this distant world.

On Earth there are places on the ocean floor where volcanic activity from below creates what are called hydrothermal zones where water and rock meet at high temperature.  These local environments are rich with diverse life forms which are sustained by energy and nutrients which are created as seawater interacts with the warm rocky ocean floor.
If as the data suggest,  Europa has a liquid salt water ocean in direct contact with warm rock layers then the key ingredients for life .. liquid water, nutrients, and a source of energy are all together in one place.   

For Travelers in the Night this is Dr. Al Grauer.

End of podcast:

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