Extra - Solar Planets


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The Search for Extra-Solar Planets


One of the largest projects going on in space exploration today is the search for and discovery of planets orbiting other stars.  These planets are what scientists refer to as extra-solar planets.  At present, there has been over 3,700 of these planets discovered ranging in size from Jupiter - sized or larger down closer to Earth-sized.  As techniques for finding extra-solar planets improve, whole solar systems with many planets will be discovered.  And with more planets being found, the more opportunities there will be to find intelligent life in the universe.


The Discoveries


Extrasolar planets were thought by scientists for years to exist but it wasn't until October 6, 1995 that the first extrasolar planet was discovered to be orbiting a sun-like star known as 51 Pegasi in the constellation Pegasus.  Sinced then, planets have been discovered orbiting stars such as 70 Virginis in the constellation Virgo, 55 Cancri in Cancer, Tau Bootes in Bootes, 16 Cygni in Cygnus and many others since then.  All told, the current extrasolar planet count stands at 3,944 confirmed with 2,941 stars having planets orbiting them.  There are also 3,504 extrasolar candidates listed for a grand total of 7,448 extrasolar planets.  The number of terrestrial type planets found stands at 156.


In discovering extrasolar planets, one of the methods scientists use makes use of the fact that when a planet orbits a star, the planet's gravitational pull causes the star to wobble slightly.  When the star wobbles toward the Earth, its lightwaves are shifted to the blue end of the light spectrum or blue shifted.  When the star wobbles away from the Earth, its lightwaves are shifted toward the red end of the spectrum or red shifted.  Scientists examine these differences in wavelengths and can thus determine the planet's size and orbital characteristics.  This method is called the radial velocity method.  Other methods are also being used in extrasolar planet detection such as astrometry which uses the precise measurement of a star as compared to backround stars; the transit method which measures the periodic diming of a star by a planet passing in front of it; and then there is the direct detection method where scientists must cancel out the light of the target star to be able to detect the planet.  As scientists improve their methods to detect these extrasolar planets, many more will be discovered.  The future for discovering new worlds certainly looks exciting. 


For more information on extrasolar planets, visit these websites


1. Alien ExoPlanets Like Earth - 2014 Documentary Program

2. Deep Space/Mysterious KEPLER 186F Planet - 2017 Documentary Program

3. Exoplanet Exploration:  Planets Beyond Our Solar System

4. Giant Planets Orbiting Faraway Stars

5. Kepler Discoveries

6. Known Planetary Systems

7. List of Exoplanetary Host Stars

8. List of Multiplanetary Systems

9. New Worlds Atlas - Planet Quest

10. Other Worlds, Distant Suns - A Catalog of Extrasolar Systems

11. Planetary Habitability Laboratory - Habitable Exoplanets Catalog

12. Pulsar Planets: Strange Worlds Orbiting Undead Stars

13. TESS: A New Era  of Exoplanet Discovery - Youtube presentation

14. The Extrasolar Planet Encyclopedia

15. The Search for Extrasolar Planets

16. Transiting Exoplanet Survey Satellite

17. Transitsearch.org

18. Traveling to Other Galaxies - The Search for Earth-like Alien Planets - Space Documentary


Extra-Solar Planet News


Can We Spot Volcanoes on Alien Worlds?  Astronomers Say Yes   -  Harvard-Smithsonian Center for Astrophysics Press Release, September 7, 2010

Using Planet Colors to Search for Alien Earths   -  NASA News Topics Report, November 2, 2010

NASA's Spitzer Reveals First Carbon-Rich Planet   -  Caltech News Release - December 8, 2010

NASA's Kepler Mission Discovers Its First Rocky Planet   - NASA News Report - January 10, 2011

Earth-Like Planets Orbit Nearby Red Dwarf Stars, Say Scientists  - Space.com You Tube Video - February 6, 2013

Alien Planet Found Orbiting Star That's Just Like Our Sun (Video)   - Huffington Post.com - January 15, 2014

Super-Habitable World May Exist Near Earth  - Astrobiology.com News report - March 14, 2014

Astronomers Discover First "Ice Giant" Exoplanet  - PlanetQuest News - October 24, 2014

NASA's Spitzer Spots Planet Deep Within Our Galaxy  - NASA/JPL News report - April 14, 2015

Circular Orbits Identified for Small Exoplanets  - MIT News - June 1, 2015

Mars-size Planet Orbits Distant Star  - Planet-Quest News - June 17, 2015

Hunting for Exoplanets Via TESS  - Many Worlds.space - March 15, 2016

NASA's Spitzer Maps Climate Patterns on a Super-Earth  - NASA Press Release - March 30, 2016

A Planet 1,200 Light-Years Away is a Good Prospect for  a Habitable World  - UCLA Newsroom - May 26, 2016

Potentially Habitable Planet Found Orbiting Star Closest to Sun  - National Geographic - August 24, 2016

SOFIA Confirms Nearby Planetary System is Similar to Our Own - NASA Press Release - May 2, 2017

Four Earth-Sized Planets Found Orbiting the Nearest Sun-Like Star - Keck Observatory News - August 9, 2017

Exoplanets: Worlds Beyond Our Solar System - Space.com - March 29, 2018