![]() If Uranus and Neptune are gas giants, why do they appear blue, unlike Jupiter and Saturn? Dr Joe Michalski talks to Museum planetary scientist Dr Ashley King about this image of Neptune and Triton, and asks about the planets' unusual appearance. ![]() However, the storm disappeared before it could be photographed by the Hubble Space Telescope in 1994, meaning very little is known about how these storms form or dissipate. When Voyager 2 flew by Neptune in 1989, it saw a storm 13,000 kilometres across, which was subsequently named the Great Dark Spot. Neptune has also been seen with giant storm spots, similar in appearance to the Great Red Spot on Jupiter. In comparison, the fastest winds recorded on Earth, during tornadoes, are between 400 and 500 kilometres per hour. The resulting temperature difference is thought to contribute to Neptune's formidable weather - winds on the planet can reach almost 2,200 kilometres per hour, the fastest in our solar system. Neptune, like Uranus, is one of the two outer planets known as an 'ice giant.' Made up of more ices than Jupiter and Saturn, the chilly body almost seems to be in a class by itself. In fact, Neptune gives out 2.6 times more heat than it receives from the Sun. Wild weatherĭespite its extremely cold atmosphere, the interior of Neptune is far hotter than that of its ice giant twin, Uranus. It took this image of Neptune and its moon Triton, one of 77 composite photographs that appeared in Otherworlds: Visions of our Solar System, before speeding towards interstellar space. Since then, the planet has only been visited once by spacecraft when, in 1989, Voyager 2 completed its 'Grand Tour' of our solar system's outermost planets. The planet's sheer distance from Sun makes viewing it from Earth a challenge, and it was only discovered in 1846 after calculations of Uranus's orbit suggested there was an as-yet unknown planet affecting it gravitationally. Receiving just one nine-hundredth as much light from the Sun as the Earth does, it can experience temperatures as low as -218☌, making it one of the coldest places in our solar system. Additional Webb studies of both Triton and Neptune are planned in the coming year.Orbiting the Sun at a distance of 4.5 billion kilometres - more than 30 times further out than the Earth - Neptune is a dark, icy world. Triton orbits Neptune in an unusual backward (retrograde) orbit, leading astronomers to speculate that this moon was originally a Kuiper belt object that was gravitationally captured by Neptune. It far outshines Neptune in this image because the planet's atmosphere is darkened by methane absorption at these near-infrared wavelengths. Rather, this is Neptune's large and unusual moon, Triton.Ĭovered in a frozen sheen of condensed nitrogen, Triton reflects an average of 70% of the sunlight that hits it. Dominating this Webb portrait of Neptune is a very bright point of light sporting the signature diffraction spikes seen in many of Webb's images, but this is not a star. ![]() Webb also captured seven of Neptune's 14 known moons. ![]() A previously-known vortex at the southern pole is evident in Webb's view, but for the first time Webb has revealed a continuous band of high-latitude clouds surrounding it. Neptune's 164-year orbit means its northern pole, at the top of this image, is just out of view for astronomers, but the Webb images hint at an intriguing brightness in that area. This is readily apparent in Neptune's signature blue appearance in Hubble Space Telescope images at visible wavelengths, caused by small amounts of gaseous methane. Compared to the gas giants, Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. This planet is characterized as an ice giant due to the chemical make-up of its interior. At that extreme distance, the sun is so small and faint that high noon on Neptune is similar to a dim twilight on Earth. Located 30 times farther from the sun than Earth, Neptune orbits in the remote, dark region of the outer solar system. Neptune has fascinated researchers since its discovery in 1846. Webb's extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune. "It has been three decades since we last saw these faint, dusty rings, and this is the first time we've seen them in the infrared," notes Heidi Hammel, a Neptune system expert and interdisciplinary scientist for Webb. In addition to several bright, narrow rings, the Webb image clearly shows Neptune's fainter dust bands. Most striking in Webb's new image is the crisp view of the planet's rings-some of which have not been detected since NASA's Voyager 2 became the first spacecraft to observe Neptune during its flyby in 1989.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |