One way to find water worlds beyond our solar system is to look for minerals, more specifically by studying minerals mixed with cold lava on the surfaces of exoplanets. This is because water contact with fresh, cooling lava can promote the formation of certain minerals within the lava. So finding these minerals can get you closer to the water that formed them. It doesn’t matter whether water is on the surface of an exoplanet or hidden underground.
Of course, this concept actually assumes some exoplanets. have It’s cooled lava that our equipment can inspect (and therefore has shown volcanic activity at some point in the past), but the odds are in our favor. Within our solar system, we have discovered lava flows on Mercury, the Moon, Mars, and Jupiter’s moon Io. It is likely that every rocky world was a volcanic world at some point in its history.
So a team of researchers recently built a database of how certain minerals in the cooled lava of exoplanets might appear on the James Webb Space Telescope, one of astronomy’s most powerful tools.
The research team decided to focus on a material called basalt. This dark, fine-grained rock is formed when lava flows to the planet’s surface and then cools. It is also one of the most common rocks in our solar system and probably the rest of the galaxy.
“We know that most exoplanets will produce basalts,” said Esteban Gazel, an engineer at Cornell University and co-author of the study on the database. name. Gazel went on to explain that the chemical composition of most stars hosting exoplanets that we have discovered suggests that the planets must be composed of material suitable for forming basaltic lavas. “It will be widespread not only in our solar system, but throughout the galaxy.”
The truth lies in basalt
Looking at a plate of basalt can tell us a lot about where and how it formed, including whether there was liquid water around it while it was forming.
As previously mentioned, when water flows across cooling lava or through cracks in rock, it can form minerals such as amphibole or serpentine, which appear in volcanic rocks here on Earth. Each of these minerals must absorb and emit specific wavelengths of energy, like chemical fingerprints written in light, and JWST can capture these wavelengths. So basically, by using JWST to measure the spectrum of light emitted by distant planets, astronomers can find out what the light source is.
“We are testing basaltic material here on Earth to uncover the composition of exoplanets through James Webb Space Telescope data,” Gazel said.
He and his colleagues measured the light spectra of 15 basalt samples. Each sample was taken from a different environment on Earth and contained a different mix of minerals. They used a computer program to simulate what the basalt data would look like if they came from the surface of a rocky planet called LHS 3844b, about 48 light-years away and visible through JWST’s Mid-Infrared Instrument (MIRI). ).
According to the statement, by examining small spectral differences between basalt samples, scientists could theoretically determine whether an exoplanet has surface water or water flowing in its interior.
But it will be some time before astronomers can test the library of basalt spectra. Measuring the spectrum of lava flows spread across the surface of a distant world would take tens, even hundreds of hours, more than the time of the high-demand JWST. Astronomers are often lucky enough to have only a few hours to aim their telescopes at their chosen target.
Research on the database was published Nov. 14 in the journal Nature Astronomy.
