We live on a planet that is third from a star we call the Sun. Our place in the solar system is very unique and is what scientists call The Goldilocks Zone or the habitable zone. If you remember your childhood fairy tales, you’ll understand why it has been called this. We live in an orbit around our star that allows the temperatures to be not too hot, and not too cold, but just right – allowing there to be liquid water and the formation of life to occur. If our planet had been as little as 1%, or 4 diameters of our moon closer to the sun the temperatures would have been too hot for liquid water to exist. If our planet’s orbit was as little as 2% further away from the sun, any water on our planet would freeze. These small changes in distance would alter the conditions on our planet and could change the possibility of the formation of life.
In the search for exoplanets, one of the things astronomers try to determine is if that planet is in the habitable or Goldilocks zone around their star. If a planet falls into this area there could be the possibility of liquid water on the planet. If there is a possibility of liquid water on the surface of the planet, this could mean that there might also be the possibility of life. One of the problems with the news stations reporting on these discoveries is that they do not give enough information for everyone to truly understand what the discovery means. Agencies tend to sensationalize the news to make it exciting and to catch everyone’s attention.
A few years ago there was one such report on the local and national news that caused excitement in my students and a buzz in the classroom that resulted in me throwing away my lesson plans for the day. “Mrs. Trembley, did you hear? There is an Earth-like planet only seven light years away!” I was flooded with a mixture of emotions, first impressed that my students actually paid attention to the news, next happy that they were excited about an astronomical event, then resigned to having to put aside my lessons for the day and use this as a teachable moment in my classroom.
Yes, the news stations were all reporting that an Earth-like planet had been found and it was only seven light years away from Earth. I understood how my students were viewing this information, and I had to make sure that I corrected their understanding and deflated the delusions that the news had given them. Let me break this statement down and explain how my middle school students, as well as some adults in the building, took this news. When the news reports on an Earthlike planet, the public believes that there is a planet just like our Earth that has been found out in space. In their minds, they see a planet with continents filled with trees and mountains, and oceans flowing over the surface.
As humans we tend to relate things to what we already know, we know about our Earth so that means if there is an Earth-like planet out in space, then it must be just like ours. They don’t have the knowledge to understand that the planet has been found in the habitable, or Goldilocks zone around its star, leading to the possibility of water. They think we have seen this planet with its continents, oceans, and atmosphere and that is just like the one we live on. They don’t have the knowledge that will help them understand that we haven’t seen this planet with all these things, but through mathematics and measurements, astronomers have been able to determine the size of the planet and its location around its star. Based on these measurements they can determine its orbit and that the planet is in the habitable zone around its star.
Editor: The JWST is actively looking at the spectra of the atmospheres of exoplanets – but this has occurred after Constance’s retirement, so she was never able to discuss this with her students.
The bigger issue is the part of the news that reported it was “only seven light years away.” Like most people, if they don’t understand a word, they just drop it from the sentence, so seven light years becomes seven years. Vocabulary and word choice have a huge effect on our understanding of the information we are given. After a classroom discussion of this statement I discovered that the word only gave my students an indication that the planet was within our reach. They needed to understand what a light year was, and what it meant to how far this planet was from ours. A light year is not a measurement of time but a measurement of distance, it is a measure of how far light travels in one year.
If you live in the United States, a light year would be 186,282.42 mi/s (that’s miles in one second). For the rest of the world it would be 300,000km/s (that’s kilometers in one second). So to determine how far light travels in one year, remember the planet was only 7 light years away, we need to do a little math. It’s not difficult math, but it is using some very large numbers and is impressive when I do it for my students on the board. I’m aware there are calculators and computers that can do the calculations for me, but I was trying to impress a point in my students minds. My math on the board went something like this; if a light year is measured using a second, how many seconds are in a minute? Well you multiply the speed of light by 60 to find out how far it has traveled in one minute. How many minutes are in an hour? How many hours in a day? (of course we use an Earth day) Then finally how many days are in an Earth year? As I did each multiplication my students’ eyes widened and comments of stunned surprise started bouncing around the room. In the end they found out that light travels 6 trillion miles in one year, or 9.5 trillion kilometers. However we weren’t done, the planet that was discovered was 7 lightyears away so the final multiplication was to take that light year and multiply it by seven to find its distance from our planet.
That Earth-like planet that was only seven lightyears away turned out to be 42 trillion miles, or 66.5 trillion kilometers away, and that is if we could travel at the speed of light. Teaching my students that the speed of a commercial airplane is 659 miles or 1061 kilometers per hour and the speed of light is measured in seconds is what finally helped them understand that the planet that is only 7 light years away is not anything we will be able to travel to in our lifetime, if ever. News agencies give sensational information to the public, but they leave out the important information that will allow them to have an accurate understanding of what they are presenting. If they had reported “A planet was found in the habitable zone around its star, 7 light years or 42 trillion miles away from Earth” it would have given the public a better understanding of the discovery.
Why is this important? It is critical, because humans being what they are, will believe they can do whatever they want to our planet because there is an alternative place for us to move to. I believe one of the most important lessons I taught my students was that our planet with its delicate balances is what sustains our life, and that there is No Planet B for us to move to.
There is No Planet B
About the Author:
Constance Martin-Trembley has a Bachelor’s of Science degree in Elementary Education and a Master’s of Education Degree in teaching Science Education. She retired in July of 2023, after being a middle school science teacher for 23 years, 22 of those for the New Haven School District, where she has twice earned teacher of the year.
Connie grew up in Detroit in the 1960’s during the space race between the US and Russia. This time in history sparked a life long interest in space for many young children including Connie. Connie has had the privilege of having an asteroid named after her, (117852) Constance, for the promotion of space education among children.
Connie is married to Bob Trembley – they are both volunteer NASA JPL Solar System Ambassadors, and promote space education at public venues, giving lectures about various space related topics. Connie has a particular fascination about the 1960’s space race and those involved.
Connie was a guest on our Podcast in 2021:
Image: Artist’s concept of exoplanet Gliese 273 e. Credit: Bob Trembley / SpaceEngine. This shows the sunlit side of the exoplanet used in the cover image – which shows red dwarf Gliese 273 seen through the exoplanet’s ring system (also an artist’s concept).
Click here to explore exoplanets in NASA’s interactive “Eyes on Exoplanets” web app.
