James Webb Space Telescope's first 'alien world' discovery unlocks new era of planet-hunting
Scientists have unveiled groundbreaking direct images of a planet outside of our own solar system, taken by the James Webb Space Telescope.
It is the first exoplanet discovered by the telescope, proving it can detect lighter and more elusive worlds orbiting distant stars.
The planet, named TWA 7b, is situated near a young star about 34 lightyears away, in the constellation Hydra.
It is the lightest exoplanet ever seen through direct imaging, with a mass similar to Saturn and about one-third that of Jupiter, as scientists are now able to study smaller, cooler planets that are more difficult to detect.
The findings were published in the Nature science journal on Wednesday.
Dr Anne-Marie Lagrange, a researcher with the French National Centre for Scientific Research (CNRS), led the study by an international team.
'Our observations reveal a strong candidate for a planet shaping the structure of the TWA 7 debris disc, and its position is exactly where we expected to find a planet of this mass,' she said.
How the planet was found
While thousands of exoplanets have been found over the past three decades, most have been detected through indirect methods. These included measuring the dimming of a star as a planet passes in front of it or by watching for tiny movements in a star caused by the gravitational pull of an orbiting planet.
Only some have ever been directly imaged, and those have typically been enormous gas giants.
TWA 7b was spotted using a powerful coronagraph installed on Webb's Mid-Infrared Instrument (Miri), a telescope attachment developed the CNRS and the French Alternative Energies and Atomic Energy Commission.
The coronagraph acted like a solar eclipse, blocking out the light of a star so that the much fainter objects orbiting nearby could be seen.
This technique helped astronomers spot a faint source of light hidden inside one of the thin dust rings surrounding the star TWA 7.
After ruling out objects such as background galaxies or image glitches, scientists realised the signal was coming from a planet, one that had never been seen before.
Computer simulations showed that the planet was placed exactly where there is a strange gap in the star's narrow dust ring, which meant strong evidence that its gravity is shaping the ring's structure.
Building on past space telescope discoveries
Since the telescope's science operations started in 2022, it has helped scientists make several discoveries. These included helping to confirm the chemical composition of atmospheres of other planets and extreme weather patterns on gas giants.
JWST's predecessor, the Hubble Space Telescope, also made valuable discoveries in the early era of direct imaging.
It captured the first visible-light image of an exoplanetary system in 2008, however, it lacked the sensitivity to see planets smaller than Jupiter.
Now, the James Webb Space Telescope is now offering more advanced techniques.
'This observatory enables us to capture images of planets with masses similar to those in the solar system, which represents an exciting step forward in our understanding of planetary systems, including our own,' said Mathilde Malin, co-author of the study.
What comes next
The team behind the discovery thinks Webb could soon be able to spot planets with just 10 per cent the mass of Jupiter, getting close to the size of Neptune and 'super-Earths', planets outside the solar system that are larger than Earth but smaller than icy planets like Neptune and Uranus.
TWA 7 b also gives scientists a roadmap for how future space and ground-based telescopes that might detect even smaller, more Earth-like planets.
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The National
a day ago
- The National
James Webb Space Telescope's first 'alien world' discovery unlocks new era of planet-hunting
Scientists have unveiled groundbreaking direct images of a planet outside of our own solar system, taken by the James Webb Space Telescope. It is the first exoplanet discovered by the telescope, proving it can detect lighter and more elusive worlds orbiting distant stars. The planet, named TWA 7b, is situated near a young star about 34 lightyears away, in the constellation Hydra. It is the lightest exoplanet ever seen through direct imaging, with a mass similar to Saturn and about one-third that of Jupiter, as scientists are now able to study smaller, cooler planets that are more difficult to detect. The findings were published in the Nature science journal on Wednesday. Dr Anne-Marie Lagrange, a researcher with the French National Centre for Scientific Research (CNRS), led the study by an international team. 'Our observations reveal a strong candidate for a planet shaping the structure of the TWA 7 debris disc, and its position is exactly where we expected to find a planet of this mass,' she said. How the planet was found While thousands of exoplanets have been found over the past three decades, most have been detected through indirect methods. These included measuring the dimming of a star as a planet passes in front of it or by watching for tiny movements in a star caused by the gravitational pull of an orbiting planet. Only some have ever been directly imaged, and those have typically been enormous gas giants. TWA 7b was spotted using a powerful coronagraph installed on Webb's Mid-Infrared Instrument (Miri), a telescope attachment developed the CNRS and the French Alternative Energies and Atomic Energy Commission. The coronagraph acted like a solar eclipse, blocking out the light of a star so that the much fainter objects orbiting nearby could be seen. This technique helped astronomers spot a faint source of light hidden inside one of the thin dust rings surrounding the star TWA 7. After ruling out objects such as background galaxies or image glitches, scientists realised the signal was coming from a planet, one that had never been seen before. Computer simulations showed that the planet was placed exactly where there is a strange gap in the star's narrow dust ring, which meant strong evidence that its gravity is shaping the ring's structure. Building on past space telescope discoveries Since the telescope's science operations started in 2022, it has helped scientists make several discoveries. These included helping to confirm the chemical composition of atmospheres of other planets and extreme weather patterns on gas giants. JWST's predecessor, the Hubble Space Telescope, also made valuable discoveries in the early era of direct imaging. It captured the first visible-light image of an exoplanetary system in 2008, however, it lacked the sensitivity to see planets smaller than Jupiter. Now, the James Webb Space Telescope is now offering more advanced techniques. 'This observatory enables us to capture images of planets with masses similar to those in the solar system, which represents an exciting step forward in our understanding of planetary systems, including our own,' said Mathilde Malin, co-author of the study. What comes next The team behind the discovery thinks Webb could soon be able to spot planets with just 10 per cent the mass of Jupiter, getting close to the size of Neptune and 'super-Earths', planets outside the solar system that are larger than Earth but smaller than icy planets like Neptune and Uranus. TWA 7 b also gives scientists a roadmap for how future space and ground-based telescopes that might detect even smaller, more Earth-like planets.
Khaleej Times
3 days ago
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For first time, Webb telescope discovers an alien planet
In addition to providing a trove of information about the early universe, the James Webb Space Telescope since its 2021 launch has obtained valuable data on various already-known planets beyond our solar system, called exoplanets. Now, for the first time, Webb has discovered an exoplanet not previously known. Webb has directly imaged a young gas giant planet roughly the size of Saturn, our solar system's second-largest planet, orbiting a star smaller than the sun located about 110 light-years from Earth in the constellation Antlia, researchers said. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). Most of the roughly 5,900 exoplanets discovered since the 1990s have been detected using indirect methods, such as through observation of the slight dimming of a star's light when a planet passes in front of it, called the transit method. Less than 2% of them have been directly imaged, as Webb did with the newly identified planet. While this planet is large when considered in the context of our solar system, it is actually the least massive one ever discovered through direct imaging - 10 times less massive than the previous record holder. This speaks to the sensitivity of Webb's instruments. This discovery was achieved using a French-produced coronagraph, a device that blocks out the bright light from a star, installed on Webb's Mid-Infrared Instrument, or MIRI. "Webb opens a new window - in terms of mass and the distance of a planet to the star - of exoplanets that had not been accessible to observations so far. This is important to explore the diversity of exoplanetary systems and understand how they form and evolve," said astronomer Anne-Marie Lagrange of the French research agency CNRS and LIRA/Observatoire de Paris, lead author of the study published on Wednesday in the journal Nature. The planet orbits its host star, called TWA 7, at a distance about 52 times greater than Earth's orbital distance from the sun. To put that in perspective, our solar system's outermost planet Neptune orbits about 30 times further from the sun than Earth. The transit method of discovering exoplanets is particularly useful for spotting those orbiting close to their host star rather than much further out like the newly identified one. "Indirect methods provide incredible information for planets close to their stars. Imaging is needed to robustly detect and characterize planets further away, typically 10 times the Earth- to-sun distance," Lagrange said. The birth of a planetary system begins with a large cloud of gas and dust - called a molecular cloud - that collapses under its own gravity to form a central star. Leftover material spinning around the star in what is called a protoplanetary disk forms planets. The star and the planet in this research are practically newborns - about 6 million years old, compared to the age of the sun and our solar system of roughly 4.5 billion years. Because of the angle at which this planetary system is being observed - essentially looking at it from above rather than from the side - the researchers were able to discern the structure of the remaining disk. It has two broad concentric ring-like structures made up of rocky and dusty material and one narrow ring in which the planet is sitting. The researchers do not yet know the composition of the planet's atmosphere, though future Webb observations may provide an answer. They also are not certain whether the planet, being as young as it is, is still gaining mass by accumulating additional material surrounding it. While this planet is the smallest ever directly imaged, it is still much more massive than rocky planets like Earth that might be good candidates in the search for life beyond our solar system. Even with its tremendous capabilities of observing the cosmos in near-infrared and mid-infrared wavelengths, Webb is still not able to directly image Earth-sized exoplanets. "Looking forward, I do hope the projects of direct imaging of Earth-like planets and searches for possible signs of life will become a reality," Lagrange said.
The National
5 days ago
- The National
Asteroid once feared to be hitting Earth now more likely to strike Moon in 2032
An asteroid that was briefly feared to be on a collision course with Earth is now more likely to strike the Moon in 2032, according to updated calculations by Nasa. Astronomers have refined the orbit of asteroid 2024 YR4 using data collected by the James Webb Space Telescope, revealing a slightly higher probability that the space rock could crash into the Moon's surface. The asteroid, about 80 metres wide, was discovered in late 2024 and initially appeared on Nasa's risk list for colliding with the Earth. More observations, however, have ruled out a direct hit. Latest calculations show that there is a 4.3 per cent chance the asteroid will strike the Moon on December 22, 2032. 'While asteroid 2024 YR4 is currently too distant to detect with telescopes from Earth, Nasa's James Webb Space Telescope collected one more observation of the asteroid before it escaped from view in its orbit around the Sun,' the agency said. Even if the asteroid were to collide with the Moon, it would have no effect on its orbit or stability, Nasa said. 'Unprecedented opportunity' Dr Dimitra Atri, principal investigator at New York University Abu Dhabi's Space Exploration Laboratory, said the probability of impact was 'relatively low', but a collision would give researchers 'an unprecedented scientific opportunity'. 'For the first time, we could observe the formation of a major lunar crater in real time using modern orbital instruments,' he said. 'Such an event would open possibilities for follow-up exploration. Rovers or astronauts could investigate the fresh impact site, yielding invaluable data about how impacts have shaped not only the Moon, but planetary surfaces throughout the solar system.' The Moon's heavily cratered surface is largely the result of asteroid and meteorite impacts over billions of years, but all those collisions happened before the age of space flight. A new impact, and one that can be observed and studied from start to finish, could reveal how craters evolve, how subsurface materials are exposed and help scientists test planetary defence strategies. A complex orbital path Jonathan Ward, a fellow of the UK's Royal Astronomical Society, said the orbital path of 2024 YR4 was still not fully understood due to factors such as the Yarkovsky effect, a force caused by the way an asteroid absorbs sunlight and radiates heat, altering its trajectory over time. 'We won't know anything better about its potential for an impact in 2032 until it comes back by the Earth in 2028,' Mr Ward said. Researchers were using the JWST to track the asteroid because it uses infrared wavelengths to detect heat signatures. But now telescopes have lost sight of the space rock as it moves behind the Sun. Mr Ward said the 2028 fly-by will be a critical opportunity to track the asteroid's position with greater precision and determine if any further course changes are likely. Could a deflection mission be possible? While there is no threat to Earth, the asteroid has renewed discussions about planetary defence, particularly following the success of Nasa's Dart mission in 2022, which intentionally slammed a spacecraft into an asteroid to chance its trajectory. 'A mission like Dart takes three to five years to prepare and launch,' Mr Ward said. 'If it ever became necessary, that gives us some time to act after the 2028 observations. 'But we still don't know the full make-up of this asteroid. It's likely a stony object, unlike Dimorphos, which was more of a rubble pile. That affects how it might respond to an impact.' Looking ahead to 2028 Nasa confirmed that no additional observations of the asteroid are expected until 2028, when it returns closer towards Earth. The asteroid is expected to pass at a safe distance, giving astronomers the best chance yet to determine whether a Moon impact in 2032 is possible.
