(ORDO NEWS) — The James Webb Space Telescope is humanity’s most advanced telescope to date. We’ve already seen Webb’s capabilities in the latest space imagery.
But what can Webb do to search for extraterrestrial life? Can Webb help us study distant planets and find out if they have life?
The James Webb Space Telescope has already revolutionized the way we look at the universe, and only a handful of images of deep space have been taken in its lifetime.
However, despite the fact that the study of space is just beginning, scientists around the world can be more than excited about what Webb will help discover.
Webb – Hubble’s official successor – will not only provide unparalleled images of our universe, but will also be a key tool that astronomers will use to learn more about the universe.
With the help of Webb, scientists will comb the cosmos and look for the key ingredients of life that are common in space.
If we want to discover life beyond the Earth – and this is the main goal of modern astronomy and planetary science – then Webb will certainly help in this, although it is not specifically designed to search for alien life.
Webb can do a lot for scientists studying alien worlds and astrobiology.
In fact, modern telescopes like Webb will allow researchers to gain unprecedented insight into the chemical composition of the atmospheres of distant exoplanets and their star systems.
Scientists can detect chemical signs of life on one of the many exoplanets discovered to date, and Webb could be the tool to make it possible.
But to find out where we are truly alone in the universe, we don’t have to look for distant star systems. In fact, many scientists believe that life as we know it could even exist in the solar system, virtually anywhere there is liquid water. One such example would be Mars.
Although the Red Planet is barren and dangerous to life on the surface, below the surface, in the aquifers deep below Mars, life could probably thrive.
Another great place to look for alien life is the moons of Saturn and Jupiter. For example, Europa is one of the most promising candidates for the existence of alien life.
The search for life in these places is extremely difficult because they are difficult to access, and physical samples must be returned to detect life.
And even if we find evidence that in the entire solar system, only the Earth is habitable, many experts believe that there are reasonable chances that life originated on planets orbiting distant stars.
Even more interesting is that, according to our best estimates, there may be from 100 to 300 million habitable planets in the Milky Way galaxy alone.
Indirect methods for measuring the influence of a planet on a nearby star have helped discover more than 5,000 exoplanets, including hundreds of potentially habitable ones.
These measurements make it possible to determine the mass and size of exoplanets, but little else is known about them.
Atmosphere is the key
To find out what a planet is, astronomers study its atmosphere and light spectrum.
Astronomers study how starlight interacts with planetary surfaces and atmospheres to discover life on distant planets. Light can carry a clue, known as a “biosignature”, if the atmosphere or surface has been transformed by life.
Despite the fact that simple single-celled life existed on Earth, during the first half of its existence, the atmosphere did not contain oxygen.
Therefore, at an early stage in the evolution of the Earth, its biosignature was weak. Everything changed dramatically when a new family of algae appeared 2.4 billion years ago.
Algae photosynthesize by releasing free oxygen, that is, oxygen that is not chemically bound to any other element. Since then, Earth’s oxygen-filled atmosphere has left behind a biosignature that can be easily detected by the light passing through it.
Wavelengths of light that bounce off a surface or pass through a gas are trapped more than others. As a result, objects have different colors due to the selective capture of light wavelengths.
Let’s take leaves as an example. The chlorophyll in the leaves is especially good at absorbing light in the red and blue wavelengths. Therefore, most of the light that hits the sheet is reflected in green, as the red and blue waves are absorbed.
Light interacts with materials in specific ways, resulting in unique patterns of transmitted light. By measuring the particular color of light coming from an exoplanet, astronomers can learn something about its atmosphere or surface.
Some atmospheric gases associated with life, such as oxygen or methane, leave a very specific light trail that can be detected using this method. You can also detect strange colors on the surface of the planet.
For example, in plants and algae, chlorophyll captures certain wavelengths of light during photosynthesis. A sensitive infrared camera can detect the characteristic colors of these pigments. The presence of chlorophyll on a distant planet may be indicated by this color reflected from its surface.
Similarly, astronomers studying space and wondering if there is intelligent life out there could point their telescope at Earth and look for signs that hint at the existence of life on Earth.
However, detecting these subtle changes in light from a potentially habitable exoplanet would require an incredibly powerful telescope. The new James Webb Space Telescope is currently the only telescope capable of such a feat.
How ‘James Webb’ can help us find alien life
In July 2022, James Webb began science work by taking spectrum readings from WASP-96b, a gas giant atmosphere exoplanet. Water and clouds have been found in the spectrum, but life is unlikely to exist on a planet as large and hot as WASP-96b.
Despite this, James Webb has shown that weak chemical signatures can detect light from exoplanets. As part of the planned mission, Webb will point its cameras at TRAPPIST-1e, a potentially habitable planet located 39 light-years away.
As a planet passes in front of its host star, Webb can capture the star’s light as it filters through its atmosphere to observe biosignatures. However, the Webb telescope was not designed to search for life, so it can only observe a few nearby potentially habitable planets.
But this may be more than enough.
In addition, it can only detect changes in the levels of carbon dioxide, methane, and water vapor in the atmosphere. Webb can’t detect unbound oxygen, the most powerful signal for life, although certain combinations of these gases may suggest the presence of life.
At the beginning of the Paleoproterozoic, unbound oxygen (also called molecular dioxygen, O2) was first discovered on Earth in large quantities.
More powerful telescope than Webb
If we want to find out if we are alone in the universe, then we need a better tool, more suitable for solving a specific problem. And the key to finding life on distant planets is blocking the light.
In the future, with even more powerful telescopes, starlight reflected from the planet’s surface will be revealed by blocking out the star’s bright light. It’s like blocking something in the distance with your hand to see better.
Future space telescopes could use small internal masks to achieve this, as it becomes much easier to study the light bouncing off a planet when the star’s light is blocked.
However, we don’t have to send telescopes into space to determine if there are signs of life on distant exoplanets.
In fact, three massive ground-based telescopes under construction – the Giant Magellan Telescope, the 30m Telescope and the European Extra Large Telescope – could be the best tools for astronomers to answer the question of whether we are alone in the universe.
These telescopes are much more powerful than all the existing telescopes on Earth.
Astrobiologists will only be able to detect biosignatures on planets completely transformed by alien life, even with the most powerful telescopes of the coming decades.
Methane is one of the most common gases emitted by terrestrial life, but the process of methane production can also be driven by non-biological processes.
This means that if astronomers look for life at a distance and find a signal indicating life, it could be a false positive. To rule out false positives, astronomers must study the planet well enough to determine if its atmospheric or geological processes are similar to a biosignature.
Exoplanet research may one day break the bar needed to prove the existence of life by providing the extraordinary evidence needed. While we look forward to the rich discoveries that the James Webb Space Telescope will bring, the first release of data from the telescope gives us a glimpse of what lies ahead.
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