Two articles in Science News April 28 and May 12, 2018, focus on what we have learned about the 5000 possible exoplanets Kepler has found. Now we await results from the new space telescope TESS, launched April 18. It will focus on “…nearby, bright stars that will be easy for other telescopes to further investigate later… 2000,000 stars within a few hundred lights years [of Earth]… while observing 85% of our sky.” Its findings of stars’ brightness and their planets’ mass (hence their composition and possible atmosphere) will suggest where NASA’s James
Webb Space Telescope should be pointed in 2020. It should be able to sniff exoplanetatmospheres and detect molecules possibly produced by life.
An article by Lisa Grossman in Science News (page 28) summarizes what we have learned from Kepler’s work confirming 3717 exoplanets (as of April 12, 2018). She describes the role a parent star plays in how its orbiting planets are built. A sun’s composition can suggest that its
planets may have oxygen or plate tectonics.
High-metal stars , especially large ones with close-in planets, probably form more planets. A planet’s size and mass (determined by gravity-produced wobble) determine its density, which suggests either solid rock or not–just an atmosphere, like Jupiter and Saturn. Compositions of planets can vary widely.
There is a “…surprising lack of planets between 1.5 and 2 two times Earth’s size…” Smaller ones are probably rocky; larger ones are more likely “gassy.” Though TRAPPIST and K2-229b are Earth-size, their compositions are very different from Earth. Of special interest are the
TRAPPIST-1 planets. Seven are Earth-sized with three in the Goldilocks zone of liquid water.
We look forward to what TESS finds. There are probably more surprises out there. Meanwhile, for a bit of realism, let’s remember that our Milky Way is only 100,000 or so light years wide. We humans have been sending radio waves out into the cosmos for only 80 years, so our
“signals cover less than 0.001 percent of the Milky Way. (Lisa Grossman in Science News April 14, 2018, page 9). So far the evidence suggests that simple life forms might find a place to organize and reproduce, but complex critters like us may be quite rare in this huge universe. Then there is the thought-provoking question: Can advanced civilizations last long enough to find each other?
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-
Reviews of significant books- http://www.goodreads.com/Cary_Neeper
How the Hen House Turns- http://www.ladailypost.com
Complexity, Bio, Bibliography and Links- http://caryneeper.com
Astrobiology- https://astronaut.com search:Who’s Out There