Investigating the Possibility of a ‘Twin’ Planet to Earth and its Effect on our Climate and Future Habitability
Scientists are getting really close to discovering a planet similar to Earth called its “twin”. If they do find it, they can use that as an example of what could happen to Earth in the future and if our planet will suffer from something like a really hot climate like Venus.
Researchers started with more than 300 planets that circle other stars, and they called them exoplanets. Then they chose the 5 planets that were closest in size and shape to our planet Venus as well as their distances from their own stars.
Recently, a paper was released showing the planets that are most similar to Venus. The paper also compared how bright the stars were that these Venus-like planets orbited around. This makes it more likely for the James Webb Space Telescope to get information about what their atmospheres are made of.
Today, Venus is surrounded by clouds made out of something called sulphuric acid and does not have any water. The temperature on its surface can get really hot – up to 900 degrees Fahrenheit! That’s hot enough to even melt lead! By using the Webb telescope to look at planets like Venus that are similar but not the same (these planets are known as exoVenuses), scientists want to know if our Venus has always been like this or if it used to be different.
Colby Ostberg from University of California, Riverside asked an interesting question – Could Venus ever have been a livable place? The answer lies in studying the planets that don’t get too much energy from their stars on the outer edge of Venus’s zone.
In 2014, UCR astrophysicist Stephen Kane came up with an idea called the Venus Zone. This is kind of similar to a habitable zone – that’s an area around a star where liquid could be on the surface.
Basically, in the Venus Zone it’s too hot for water but not so hot that the planet loses its atmosphere. We’re looking for planets with a lot of atmosphere still there.
The mass of a planet is important because it affects how long the planet’s inside can stay active. On the surface of our planet, this movement of rocky plates across Earth’s outer shell is called ‘plate tectonics.’
Venus has 20% less mass than Earth, which means that scientists think there may not be any plate-tectonic activity happening on Venus! Because of this, Venus might have a harder time getting rid of carbon in its atmosphere.
This month, a new scientific study suggested that Venus might still have active volcanoes. This study looked at similar planets to get more information about the activity inside them and if those activities are common or not. The author of the study, Kane, said that this work will be able to help us find out more.
Scientists have proposed to use the Webb Telescope in 2024 to explore some newly discovered planets. The Webb Telescope is a super advanced and expensive tool which can help us see if these planets have an atmosphere as well as what it’s made of. These observations could even show hints of life, like methane, methyl bromide, or nitrous oxide gases.
Finding molecules on an exoVenus proves that living things could exist in the Venus Zone and suggests that maybe it was a pleasant temperature there at some point in time. NASA has two projects related to this coming up – DAVINCI will measure gases in the atmosphere of Venus, while VERITAS is going to help map out its terrain.
Kane has been asking, in many of his works, a really important question: why is the environment on Earth different from the one on Venus? Could it be that one or both planets are strange in their own way? It’s tough to answer this when we’re looking at only two planets in our Solar System. But thanks to exoplanet explorations, we can learn more and figure out why they are different.
If the planets on the list turn out to be similar to Venus, it means that what happened to Venus is something that happens a lot. This could also be a warning for us here on Earth since this could happen to us too. We need to study what happened on Venus so we don’t have the same fate.
Reference: “The Demographics of Terrestrial Planets in the Venus Zone” by Colby Ostberg, Stephen R. Kane, Zhexing Li, Edward W. Schwieterman, Michelle L. Hill, Kimberly Bott, Paul A. Dalba, Tara Fetherolf, James W. Head and Cayman T. Unterborn – Published on 21st March 2023 in The Astronomical Journal with the DOI: 10.3847/1538-3881/acbfaf
