The James Webb Space Telescope has turned its gaze from the deep universe to our Solar System, capturing an image of luminous Neptune and its delicate, dusty rings in a level of detail not seen in decades, NASA said Wednesday.
The last time astronomers had such a clear view of the planet furthest from the sun was when NASA’s Voyager 2 became the first and only space probe to fly past the ice giant for just a few hours in 1989.
Now Webb’s unprecedented infrared imaging capabilities have provided new insight into Neptune’s atmosphere, said Mark McCaughrean, senior adviser for science and exploration at the European Space Agency.
The telescope removes all the glare and background so “we can start to tease out the atmospheric composition” of the planet, said McCaughrean, who has worked on the Webb project for more than 20 years.
Neptune appears deep blue in earlier images taken by the Hubble Space Telescope due to methane in its atmosphere. However, infrared wavelengths captured by Webb’s main NIRCam imager show the planet as grayish-white with icy clouds streaking across the surface.
The image also shows an “intriguing glow” near the top of Neptune, NASA said in a statement. Because the planet is tilted away from Earth and takes 164 years to orbit the Sun, astronomers haven’t gotten a good look at its north pole yet.
Above Neptune is what appears to be a very bright, pointed star, but it is actually Triton, Neptune’s strange and huge moon. Triton, which is larger than the dwarf planet Pluto, appears brighter than Neptune because it is covered in ice, which reflects light. Neptune “absorbs most of the light that falls on it.” Because Triton orbits Neptune backwards, it is believed that it was once a nearby Kuiper belt object, which was captured in the planet’s orbit. “So it’s great to go and take a look,” McCaughrean said.
As astronomers scour the universe for other planets like our own, they’ve found that ice giants like Neptune and Uranus are the most common in the Milky Way. “By being able to observe these in great detail, we can introduce our observations of other ice giants,” McCaughrean said.
In operation since July, the Webb is the most powerful space telescope ever built and has already returned an unprecedented wealth of data. Scientists hope it heralds a new age of discovery.
“The kind of astronomy we’re seeing now was unimaginable five years ago,” McCaughrean said. “Of course we knew it would do this, we built it to do this, it is exactly the machine we designed. But to suddenly start seeing things at these longer wavelengths that were previously impossible… it’s absolutely extraordinary.”
Associated Press/OnCuba.
