UPDATE:
Read about possible conditions and characteristics of Proxima b
This is a day in the history of humanity that will be remembered because of something discovered in the field of astronomy.
Competing with the headlines of a major earthquake with death and destruction in Italy, a severe tornado in Indianapolis, the torrid U.S. Presidential campaign, shameful skyrocketing of a lifesaving drug in the name of money only and not true costs, and terrorist attacks, we now have clear evidence for the closest exoplanet to Earth.
Known as Proxima b, this exoplanet - a planet beyond those in our solar system - is in an 11.2 day orbit around its parent Red Dwarf star, Proxima. Red Dwarfs are far more numerous than more massive stars, including our Sun by a very wide margin. Proxima is also part of a triple star system in the Southern Hemisphere and is located just 4.37 light years from Earth. Proxima is the closest star to Earth after our Sun.
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This image of the sky around the bright star Alpha Centauri AB also shows the much fainter red dwarf star, Proxima Centauri, the closest star to the Solar System. The picture was created from pictures forming part of the Digitized Sky Survey 2. The blue halo around Alpha Centauri AB is an artifact of the photographic process, the star is really pale yellow in colour like the Sun.
Digitized Sky Survey 2
Acknowledgement: Davide De Martin/Mahdi Zamani |
Proxima b has a mass at least 1.3 times that of Earth and is located within the habitable zone which means that if water exists on the planet, it would be liquid as the surface temperature allows it. The planet would be rocky like Earth and we do not know if it has an atmosphere or not. We will have the capability to determine if there is an atmosphere with the future launch of James Webb Space Telescope (JWST) and other monster ground based telescopes.
This video simulation takes the viewer on a journey at 20% of the speed of light to the closest star, Proxima Centauri. Here we can see the planet Proxima b, which orbits its red dwarf star every 11.2 days. This planet orbits within the habitable zone, which means that liquid water could exist on its surface.
PHL @ UPR Arecibo, ESO. Music by Lyford Rome
Details on how the international team of astronomers discovered Proxima b can be read here and here. It was quite the cooperative effort spanning years to discern the very, very small wobbling of the star caused by the gravitational pull of Proxima b.
The reason why I feel this is an historic finding is that there will not be an exoplanet closer to Earth than Proxima b. The reason is that there are no stars closer to us than Proxima - none. Adding in the currently known qualities of Proxima b - potential for liquid water, a rocky planet like our solar system's 4 inner planets, a mass a bit more massive than our planet and a star that will produce energy for a TRILLION years and you have the potential for life as we know it to develop.
Planets outnumber stars in our Galaxy trillions vs hundreds of billions. To find an exoplanet with qualities of Proxima b around the most common type of star there is and be the closest star/exoplanet to our planet that we will ever find - is in a word THRILLING.
I have seen Alpha and Beta Centauri with my own eyes and captured their light with my camera knowing it had taken 4.3 years travel time for their photons (light) to reach me. I took pics of the pair in 2016 so their light left in 2012.
I hope to gaze upon them again in person so I can imagine the POSSIBILITY of life being there so close to us. 25 trillion miles is still a haul (there are 6 trillion miles in a light year, the distance light travels in one year at 186,000 miles per second) but it is the closest star to us after the Sun at 8 light minutes or 93 million miles.
Our Sun will die in about 5 billion years and engulf the Earth. Whatever life remains in the solar system will have to go somewhere. Perhaps Proxima b will be the place to go as Proxima the star will be around for a long, long time.
Sky Guy in VA
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