A blazing gas giant cloaked in dusty red clouds has been spotted in unprecedented observations of a planet beyond our solar system.
The observations, which astronomers said marked a “historic moment for astronomy”, are the first direct images of a planet beyond our solar system made by $10bn (£8.65bn) Nasa . James Webb Space Telescope. They are also the first images of an exoplanet using infrared light, which gives a much more accurate indication of a planet’s mass and temperature and will allow astronomers to see the movement of clouds drifting across the planet’s sky.
“This is truly a historic moment for astronomy,” said Prof Sasha Hinkley, a University of Exeter astronomer who co-led the observations. “James Webb will open the door to a whole new class of planets that were completely beyond our reach, and by observing them over a wide range of wavelengths we can study their composition in much more detail.
“We will be able to detect the presence of weather.”
Direct imaging of exoplanets is a major technical challenge because the host star is so much brighter. The focus of the most recent observation, HIP 65426 b, is a gas giant about five to ten times the mass of Jupiter at 385 light years from the earth to the centaur Constellation.
It’s about 100 times farther from its parent star than Earth is from the Sun, making it easier to tell apart. But it’s still more than 10,000 times fainter than its parent star — the equivalent of trying to spot a firefly next to a large lighthouse from more than 50 miles away.
The latest observations put the planet’s atmospheric temperature at around 1,300 °C (2,370 °F) and suggest that its atmosphere contains red-hued clouds of silicate dust. “It would be an awful place to live,” Hinkley said. “You’d be roasted alive if you could float around in the atmosphere.”
Previously, astronomers using ground-based telescopes have obtained direct images of about 20 exoplanets, including HIP 65426 b. However, this meant contending with noise introduced by Earth’s atmosphere and confining observations to a narrow range of visible wavelengths. In contrast, the latest images captured from the cold, vacuum environment of space span a broad range of wavelengths, including the infrared, which accounts for most of the light produced in the planet’s atmosphere.
“The best wavelength to observe a planet is the one where it produces the most intrinsic light, as this is directly related to the planet’s temperature,” said Dr. Beth Biller, co-project leader and astronomer at the University of Edinburgh. .
HIP 65426 b is only 10-20 million years old, much younger than the 4.5 billion-year-old Earth, and the latest observations provide new insights into how Jupiter and Saturn may have looked when they were young.
dr Vivien Parmentier, Associate Professor of Physics at Oxford University, who was not involved in the latest work, said: “Opening a new window on the universe always brings surprises. Planets form large and contract over time, and this baby planet appears to have shrunk faster than we anticipated. This gives us amazing insights into the formation of planets and how our own solar system forms.”
In the future, the James Webb is expected to make detailed observations of more Earth-like distant planets, including those with potentially habitable conditions.
The results will be published in a preprint that will be published on the Arxiv website.