Astronomers develop new method to detect oxygen on exoplanets
Scientists have developed a new method for detecting oxygen in exoplanet atmospheres – an important indication for extraterrestrial life.
American astronomers use the James Webb telescope from NASA to detect changes in light signals caused by oxygen molecules when they collide.
The James Webb Space telescope offers incredible sensitivity to light measurements compared to its predecessor, according to astronomers from UC Riverside in California, who are collaborating with NASA to develop the technology.
The signals can help scientists distinguish between exoplanets that are inhabited by extraterrestrial life and those without.
Exoplanets are too far away to travel, but may contain the answers as to whether there is other life in the universe.
“Oxygen is one of the most exciting molecules to detect because of its link with life, but we don’t know if life is the only cause of oxygen in an atmosphere,” said Dr. UC Riverside astrobiologist Dr. Edward Schwieterman.
“With this technique we can find oxygen in planets, both living and dead.”
Exoplanets are planets outside our own solar system that orbit a star other than our sun.
When oxygen molecules collide with each other, they block parts of the infrared light spectrum that are observed by the telescope.
By examining patterns in that light, astronomers can determine the composition of the planet’s atmosphere and how much of it consists of oxygen.
On Earth, oxygen is generated by living organisms such as plants, algae and cyanobacteria.
Oxygen is generated on earth when organisms such as plants, algae and cyanobacteria use photosynthesis to convert sunlight into energy
The presence of oxygen on other planets may indicate the activity of similar life forms.
However, some researchers suggest that oxygen can accumulate in the atmosphere of a planet without any life activity.
This can happen when an exoplanet is too close to its host star or receives too much star light, making the atmosphere warm and saturated with water vapor from evaporating oceans.
This water can then be broken down by strong ultraviolet radiation into hydrogen and oxygen.
Because hydrogen atoms are very light, they can escape from the gravity of a planet in space and leave oxygen behind.
Therefore, abundant oxygen can also indicate a history of water loss – an important finding in itself to learn more about planets outside our solar system.
“It’s important to know if and how many dead planets generate oxygen in the atmosphere so that we can better recognize when a planet is alive or not,” Dr. said. Schwieterman.
The much malicious James Webb telescope (photo) was intended to replace the long-acting Hubble telescope, but is troubled by problems and delays
Last month another team of astronomers who used data from the Hubble and Spitzer space telescopes discovered that water is often in the atmosphere of exoplanets, but in small amounts.
The nearest exoplanet is called Proxima Centauri, about 4.2 light-years away from our sun.
Because technology does not exist to visit these planets, astronomers can use instruments such as the James Webb Space telescope that can measure changes in light from exoplanets, allowing them to estimate characteristics such as size, atmospheric composition, and distance to Earth.
At the launch in 2021, the much-delayed Webb telescope will study the history of exoplanets and the origins of the first stars of the universe.
“Before our work, it was thought that oxygen at levels similar to Earth was not detectable with Webb,” said Thomas Fauchez of Goddard Space Flight Center at NASA and lead author of the study, published in Nature Astronomy.
“This oxygen signal has been known since the early 1980s from atmospheric studies on Earth, but has never been investigated for exoplanet research.”
WHAT IS THE JAMES WEBB TELESCOPE?
The James Webb telescope has been described as a “time machine” that can help unravel the secrets of our universe.
The telescope will be used to look back at the first galaxies born more than 13.5 billion years ago in the early universe, and to observe the sources of stars, exoplanets and even the moons and planets of our solar system.
The huge telescope, which has already cost more than $ 7 billion (£ 5 billion), is considered a successor to the revolving Hubble Space Telescope
The James Webb telescope and most of its instruments have an operating temperature of about 40 Kelvin – about minus 387 Fahrenheit (minus 233 Celsius).
Officials say the costs can be higher than the $ 8 billion (£ 5.6 billion) program cap that Congress has set. The space agency has already deposited $ 7 billion (£ 5 billion) in the telescope.
When launched in 2020, it will be the largest and most powerful telescope in the world, which can look back 200 million years after the big bang.
In January, the telescope was successfully tested in a giant vacuum chamber at the Johnson Space Center – which proved that it will work in the deep space.
The telescope has tested cryogenically for 100 days, with the temperature falling hundreds of degrees below freezing to ensure that it functions in extreme cold.