Is there life on another planet?
In a potential landmark discovery, scientists using the James Webb Space Telescope have obtained what they call the strongest signs yet of possible life beyond our solar system, detecting in an alien planet's atmosphere the chemical fingerprints of gases that on Earth are produced only by biological processes.
The two gases - dimethyl sulfide, or DMS, and dimethyl disulfide, or DMDS - involved in Webb's observations of the planet named K2-18 b are generated on Earth by living organisms, primarily microbial life such as marine phytoplankton - algae.
This suggests the planet may be teeming with microbial life, the researchers said. They stressed, however, that they are not announcing the discovery of actual living organisms but rather a possible biosignature — an indicator of a biological process — and that the findings should be viewed cautiously, with more observations needed.
Nonetheless, they voiced excitement. These are the first hints of an alien world that is possibly inhabited, said astrophysicist Nikku Madhusudhan of the University of Cambridge's Institute of Astronomy, lead author of the study published in the Astrophysical Journal Letters.
"This is a transformational moment in the search for life beyond the solar system, where we have demonstrated that it is possible to detect biosignatures in potentially habitable planets with current facilities. We have entered the era of observational astrobiology," Madhusudhan said.
Madhusudhan noted that there are various efforts underway searching for signs of life in our solar system, including various claims of environments that might be conducive to life in places like Mars, Venus and various icy moons.
K2-18 b is 8.6 times as massive as Earth and has a diameter about 2.6 times as large as our planet.
It orbits in the "habitable zone" — a distance where liquid water, a key ingredient for life, can exist on a planetary surface — around a red dwarf star smaller and less luminous than our sun, located about 124 light-years from Earth in the constellation Leo. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). One other planet also has been identified orbiting this star.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Express Tribune
28-05-2025
- Express Tribune
Webb telescope captures deep view of ancient galaxies
The James Webb space telescope's deepest view of a single target yet depicts spinning arcs of light that are galaxies from the universe's distant past, the European Space Agency said Tuesday. The new image took the world's most powerful telescope more than 120 hours to capture, making it the longest Webb has ever focused on a single target. It is also "Webb's deepest gaze on a single target to date", the European Space Agency (ESA) said in a statement, making the image one of the deepest ever captured of the cosmos. At the bright centre of the image is a massive cluster of galaxies called Abell S1063, which is 4.5 billion light years from Earth. But it is not the true target. Such huge celestial objects can bend the light of things behind them, creating a kind of magnifying glass called a gravitational lens. Therefore the "warped arcs" spinning around the Abell S1063 are what really interest scientists, the ESA said in a statement. Because looking into distant space also means looking back in time, scientists hope to learn how the first galaxies formed during a period known as the Cosmic Dawn, when the universe was only a few million years old. The image includes nine separate shots of different near-infrared wavelengths of light, the ESA said. Since coming online in 2022, the Webb telescope has ushered in a new era of scientific breakthroughs. It has also revealed that galaxies in the early universe are far bigger than scientists expected, leading some to suspect there might be something wrong with our understanding of the cosmos.
Business Recorder
26-05-2025
- Business Recorder
Astronomers spot galaxy shaped like the Milky Way but is far more massive
WASHINGTON: Astronomers have observed a galaxy dating to an earlier epoch in the universe's history that surprisingly is shaped much like our Milky Way - a spiral structure with a straight bar of stars and gas running through its center - but far more massive, offering new insight into galactic formation. The distant galaxy, called J0107a, was observed as it appeared 11.1 billion years ago, when the universe was about a fifth of its current age. The researchers used data from the Chile-based Atacama Large Millimeter/submillimeter Array (ALMA) and NASA's James Webb Space Telescope to study the galaxy. They determined that the galaxy's mass, including its stars and gas, was more than 10 times greater than that of the Milky Way, and it was forming stars at an annual rate approximately 300 times greater. J0107a was more compact than the Milky Way, however. 'The galaxy is a monster galaxy with a high star formation rate and plenty of gas, much more than present-day galaxies,' said astronomer Shuo Huang of the National Astronomical Observatory of Japan, lead author of the study published this week in the journal Nature. 'This discovery,' said study co-author Toshiki Saito, an astronomer at Shizuoka University in Japan, 'raises the important question: How did such a massive galaxy form in such an early universe?' While a few galaxies that are undergoing star formation at a similar rate to J0107a exist in today's universe, almost all of them are ones that are in the process of a galactic merger or collision. There was no sign of such circumstances involving this galaxy. J0107a and the Milky Way have some commonalities. 'They are similarly huge and possess a similar barred structure. However, the Milky Way had plenty of time to form its huge structures, while J0107a didn't,' Saito said. In the first few billion years after the Big Bang event 13.8 billion years ago that initiated the universe, galaxies were turbulent entities and were much richer in gas than those existing currently - factors that fostered extreme bursts of star formation. While galaxies with highly organized structures like the barred spiral shape of the Milky Way are common now, that was not the case 11.1 billion years ago. 'Compared to other monster galaxies in the distant universe (dating to an earlier cosmic epoch) whose shapes are usually disturbed or irregular, it is unexpected that J0107a looks very similar to present-day spiral galaxies,' Huang said. 'Theories about the formation of present-day galactic structures may need to be revised,' Huang added. The Webb telescope, as it peers across vast distances back to the early universe, has found that galaxies with a spiral shape appeared much earlier than previously known. J0107a is now one of the earliest-known examples of a barred spiral galaxy. About two thirds of spiral galaxies observed in the universe today possess a bar structure. The bar is thought to serve as a form of stellar nursery, bringing gas inward from the galaxy's spiral arms. Some of the gas forms what are called molecular clouds. Gravity causes the contraction of these clouds, with small centers taking shape that heat up and become new stars. The bar that is part of J0107a measures about 50,000 light years in length, Huang said. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The Webb telescope 'has been studying the morphology of early massive galaxies intensely recently. However, their dynamics are still poorly understood,' Saito said.
Business Recorder
23-04-2025
- Business Recorder
Planet with comet-like tail observed disintegrating near its star
WASHINGTON: Astronomers have spotted a small rocky planet that orbits perilously close to its host star disintegrating as its surface is vaporized by stellar heat, trailed by a comet-like tail of mineral dust up to about 5.6 million miles (9 million km) long. About 5,800 planets beyond our solar system, called exoplanets, have been discovered since the 1990s. Of those, only four have been observed disintegrating in orbit, as this one is. This planet is the closest to our solar system of the four, giving scientists a unique opportunity to learn about what happens to these doomed worlds. The researchers observed the planet, named BD+05 4868 Ab, as it gradually crumbles into dust, shedding material roughly equal to the mass of Mount Everest with each orbit of its star. The tail of dust trailing the planet wraps halfway around the star. The planet is estimated as between the size of our solar system's smallest and innermost planet Mercury and Earth's moon. It is located about 140 light years away from Earth in the constellation Pegasus. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). Its host star, a type called an orange dwarf, is smaller, cooler and dimmer than the sun, with about 70% of the sun's mass and diameter and about 20% of its luminosity. The planet orbits this star every 30.5 hours at a distance about 20 times closer than Mercury is to the sun. The planet's surface temperature is estimated at close to 3,000 degrees Fahrenheit (about 1,600 degrees Celsius) thanks to its close proximity to its star. As a result, the planet's surface has probably been turned to magma - molten rock. 'We expect the planet to disintegrate into dust within the next million years or so,' said Marc Hon, a postdoctoral researcher at the Massachusetts Institute of Technology's Kavli Institute for Astrophysics and Space Research and lead author of the study published on Tuesday in the Astrophysical Journal Letters. 'This is catastrophically quick in cosmic timescales. The disintegration is a runaway process. As more material from the planet turns into dust, the disintegration process gets faster,' Hon said. Once in space, the vaporized material cools down to form mineral dust that streams away from the planet. 'We know the dust grains in the tail can have sizes between large soot particles and fine grains of sand,' Hon said. 'We don't know the mineral composition of the tail yet.' The researchers detected BD+05 4868 Ab using the 'transit method,' observing a dip in the host star's brightness when the planet passes in front of it, from the perspective of a viewer on Earth. It was found using NASA's Transiting Exoplanet Survey Satellite, or TESS, space telescope. How the planet came to have its current close-in orbit is unclear. 'The planet's orbit is not seen to be visibly decaying from the data. It is possible that the planet initially formed farther away, and had its original orbit altered under the influence of an external body, such that the planet was sent much closer to the star,' Hon said. This could have resulted from the gravitational influence of another planet or some other celestial object. The researchers plan further observations in the coming months using NASA's James Webb Space Telescope to study the composition of the material in the tail, which could give clues about the makeup of rocky exoplanets. The search for life in other solar systems focuses on rocky exoplanets orbiting stars in the 'habitable zone,' a distance where liquid water, a key ingredient for life, can exist on a planetary surface. NASA's oldest active astronaut returns to Earth on 70th birthday 'The tail is expected to contain minerals evaporated from the surface or interior of the disintegrating planet. So, this could be the crust, mantle or even the planet's core. Learning about the interiors of planets is extremely challenging. Doing this even for planets within our solar system is difficult. But BD+05 4868 Ab will allow us to directly measure the mineral composition of a terrestrial planet outside our solar system,' Hon said. 'This is definitely an exceptional opportunity for exoplanet geology and to understand the diversity and potential habitability of rocky worlds beyond our solar system,' Hon said.
