The search for life elsewhere in the Universe continues, but such is the vastness of space, any helpful tips that can point us toward planets that are likely to be habitable – and worthwhile – scientists have discovered another clue.
A new study outlines what researchers call a climate ‘decoder’, where measurements of surface colors and reflections of light bulbs observed on exoplanets can help us to Be aware of opportunities to support life or not.
Working from past climate and chemistry models, as well as observations of other stars and exoplanets, the methods astronomers have come to help act as a guide to what looks like a distant planet .
In other words, the light or spectra that our telescopes see from the Earth can effectively be codes for the atmospheric conditions of planets outside our Solar System.
“We looked at how different planetary surfaces in residential zones of remote solar systems could impact climate on exoplanets,”; said lead scientist Jack Madden from the Carl Sagan Institute at Cornell University.
“The reflected light on the planets plays an important role not only in the overall climate, but also in the observed spectra of planets like the Earth.”
The key to these calculations is the albedo of a planet, or the amount of light and radiation that reflects back. The team likens it to wearing a black or white shirt – one absorbs light and keeps you warmer, while others reflect it and keep you cooler.
The same is true of planets – their surface, atmospheric conditions, and the light that hits the planet from its nearest star all contribute to its climate, and how easy life is to thrive there .
In the same way that the color of a t-shirt can tell us how warm it is to wear, the color of an exoplanet should give advice on how intense or cold it is on the surface, even if we can’t. measure that directly.
“Depending on the type of star and the main color of the exoplanet – or the reflecting albedo – the color of the planet can relieve some of the energy the star provides,” said astronomer Lisa Kaltenegger from the Carl Sagan Institute.
“What constitutes the surface of an exoplanet, how many clouds surround the planet, and the color of the sun can dramatically change the climate of an exoplanet.”
The new study builds on previous work from Madden and Kaltenegger, looking at the observable spectra of planets in our Solar System, and what they tell us about their properties, including what they can do.
This ‘exoplanet’ color guide should be useful soon: under construction instruments such as the James Webb Space Telescope and the Giant Magellan Telescope can gather atmospheric exoplanet spectra more easily than what we can do now – the data that researchers will now be able to interpret.
Ultimately, the hope is that we can focus our attention on exoplanets that are most likely to be harboring life. Since previous models are based on what we know about our own planet and our own Sun, this new approach is better adapted for different types of planets and their host stars.
“Our results show that the use of a length-dependent albedo surface is critical for modeling potentially reliable residential exoplanets,” the researchers explained in their paper.
The research was published in Monthly Notices of the Royal Astronomical Society.