On November 13, Dr. Courtney Dressing, Assistant Professor of Astronomy at U. C. Berkeley, gave a Silicon Valley Astronomy Lecture on “Planetary Systems Orbiting Nearby Stars.” Her interests include “planet formation and evolution, the frequency of planetary systems in the Galaxy, and the prospects for detecting life on planets outside of our solar system.”
She uses telescopes to determine planet orbits, measure their mass, and “constrain their bulk composition.” Her list of planned ventures include the March 2021 launch of the James Webb Telescope. She mentioned coming launches: Europas’s Ariel, Atmospheric Remote-sensing Infrared Exoplanet Large Survey, is a 4 year study of
1000 exoplanets’ chemical composition and thermal structure. Cheops, the Characterizing Exoplanet Satellite, will take 3.5 years and measure exoplanets’ radii that have known masses, in order to learn something
about their density and composition. A deep field study by Luvoir B.is NASA’s large UV Optical Infrared Telescope with a multi-wavelength space observatory that will study reionization, gravity formation of galaxy,
star, and planet formation, and solar system remote sensing.
After reviewing present techniques for finding exoplanets, Dr. Dressing summarized our current information. Most stars close to Earth are white dwarfs and many are very small. She reported that Kepler, between 2009
and 2013, found 5000 exoplanets around various stars. Many thousands were Earth-sized. Most were the size of Jupiter orbiting close to their stars.
The average she gave was 2.5 planets per star, 1/4 Earth-sized and cool. She noted that Trapist-1 has 7 planets, 4 with liquid water. Keplar 538b has 16 Earth-sized moons, long orbital periods of 80 days. It is hot and contains more hydrogen and helium than Earth.
In April; 2018 TESS began its search of 85% of our sky with a range of 200 light years. It will take another look at the Kepler areas and will expect to find that one of five are Earth-size planets and 2 of 10 are larger than Earth. Many are probably Neptune-sized, and some are giants. So far TESS has found 1000 exoplanet candidates. Not all are either rocky or gas planets. TESS can not do measurements of mass better than Kepler.
No exoplanets found so far are obviously habitable, and the TESS search begins to suggest that we are very fortunate in living on this beautiful Earth, that the several happy accidents that resulted in the origin and
support of life were extraordinary, and that our lives could be very rare out here in the outskirts of the Milky Way.
Author of The Archives of Varok
The View Beyond Earth (Book 1.)
The Webs of Varok (Book 2.)
Nautilus Silver Award 2013 YA
ForeWord IBPA finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest (Book 4. Released Nov.21, 2016)
Excerpts, Synopses, Reviews, On Writing, Characters and More-
The Archives of Varok
Reviews of significant books- www.goodreads.com/Cary_Neeper
How the Hen House Turns- www.ladailypost.com
Complexity, Bio, Bibliography and Links- caryneeper.com
Astrobiology- astronaut.com search:Who’s Out There