Scientists Identify Misunderstanding about Uranus
2024-11-15
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1In 1781, German-born British astronomer William Herschel made Uranus the first planet discovered with a telescope.
2But, 243 years later, we still do not know much about this cold planet, the third largest in our solar system.
3And some of what we thought we knew about it turns out to be untrue.
4Much of the knowledge about Uranus was collected when NASA's robotic spacecraft Voyager 2 flew past it in 1986.
5But scientists have since learned that the craft visited at a time of unusual conditions.
6An intense solar wind event at the time led to misleading observations about Uranus, and especially its magnetic field.
7The solar wind is a high-speed flow of charged particles coming from the sun.
8The researchers took a second look at eight months of data from around the time of Voyager 2's visit and found that it flew near Uranus just a few days after the solar wind had reduced the planet's magnetosphere to about 20 percent of its usual size.
9A magnetosphere is an area of space surrounding a planet that is controlled by the planet's magnetic field.
10The magnetosphere protects the planet from solar and cosmic particle radiation.
11The Voyager 2 observations led scientists to think Uranus' magnetosphere lacked in plasma and had very intense belts of highly energetic electrons.
12Plasma is often called the fourth state of matter after solids, liquids and gases.
13In the night sky, plasma gives out light in the form of stars, nebulas, and even the auroras above the north and south poles.
14Plasma is a common feature in the magnetosphere of other planets, so scientists did not understand why there would not be much of it observed around Uranus.
15Jamie Jasinski studies space plasma at NASA's Jet Propulsion Laboratory.
16He is the lead writer of the study published recently in the publication Nature Astronomy.
17"We found that the solar wind conditions present during the flyby only occur 4 percent of the time.
18The flyby occurred during the maximum peak solar wind intensity in that entire eight-month period," Jasinski said.
19"We would have observed a much bigger magnetosphere if Voyager 2 had arrived a week earlier."
20Such a visit would likely have shown that the Uranus magnetosphere is like those of Jupiter, Saturn and Neptune, the solar system's other large planets, the researchers said.
21Uranus looks blue green because of the methane contained in its atmosphere.
22The planet is big enough to fit 63 Earths inside it.
23Among the solar system's eight planets, only Jupiter and Saturn are larger.
24Uranus orbits almost 20 times further from the sun than Earth does.
25And it has 28 known moons and two sets of rings.
26Data collected by Voyager 2 had suggested that its two largest moons - Titania and Oberon - often orbit outside the magnetosphere.
27But the new study shows that they usually stay inside the protective space, making it easier for scientists to magnetically detect possible subsurface oceans.
28"Both are thought to be prime candidates for hosting liquid water oceans in the Uranian system...," Jet Propulsion Laboratory planetary scientist and study co-writer Corey Cochrane said.
29Scientists want to learn whether subsurface oceans on moons in the outer solar system have conditions that could support life.
30So, on October 14, NASA launched a spacecraft on a mission to Jupiter's moon Europa to try to answer that question.
31"A future mission to Uranus is crucial to understanding not only the planet and magnetosphere, but also its atmosphere, rings and moons," Jasinski said.
32I'm Caty Weaver.
1In 1781, German-born British astronomer William Herschel made Uranus the first planet discovered with a telescope. But, 243 years later, we still do not know much about this cold planet, the third largest in our solar system. And some of what we thought we knew about it turns out to be untrue. 2Much of the knowledge about Uranus was collected when NASA's robotic spacecraft Voyager 2 flew past it in 1986. But scientists have since learned that the craft visited at a time of unusual conditions. An intense solar wind event at the time led to misleading observations about Uranus, and especially its magnetic field. 3Observations in a solar wind event 4The solar wind is a high-speed flow of charged particles coming from the sun. The researchers took a second look at eight months of data from around the time of Voyager 2's visit and found that it flew near Uranus just a few days after the solar wind had reduced the planet's magnetosphere to about 20 percent of its usual size. 5A magnetosphere is an area of space surrounding a planet that is controlled by the planet's magnetic field. The magnetosphere protects the planet from solar and cosmic particle radiation. 6The Voyager 2 observations led scientists to think Uranus' magnetosphere lacked in plasma and had very intense belts of highly energetic electrons. 7Plasma is often called the fourth state of matter after solids, liquids and gases. In the night sky, plasma gives out light in the form of stars, nebulas, and even the auroras above the north and south poles. Plasma is a common feature in the magnetosphere of other planets, so scientists did not understand why there would not be much of it observed around Uranus. 8Jamie Jasinski studies space plasma at NASA's Jet Propulsion Laboratory. He is the lead writer of the study published recently in the publication Nature Astronomy. 9"We found that the solar wind conditions present during the flyby only occur 4 percent of the time. The flyby occurred during the maximum peak solar wind intensity in that entire eight-month period," Jasinski said. "We would have observed a much bigger magnetosphere if Voyager 2 had arrived a week earlier." 10Such a visit would likely have shown that the Uranus magnetosphere is like those of Jupiter, Saturn and Neptune, the solar system's other large planets, the researchers said. 11Future exploration 12Uranus looks blue green because of the methane contained in its atmosphere. The planet is big enough to fit 63 Earths inside it. Among the solar system's eight planets, only Jupiter and Saturn are larger. 13Uranus orbits almost 20 times further from the sun than Earth does. And it has 28 known moons and two sets of rings. 14Data collected by Voyager 2 had suggested that its two largest moons - Titania and Oberon - often orbit outside the magnetosphere. But the new study shows that they usually stay inside the protective space, making it easier for scientists to magnetically detect possible subsurface oceans. 15"Both are thought to be prime candidates for hosting liquid water oceans in the Uranian system...," Jet Propulsion Laboratory planetary scientist and study co-writer Corey Cochrane said. 16Scientists want to learn whether subsurface oceans on moons in the outer solar system have conditions that could support life. So, on October 14, NASA launched a spacecraft on a mission to Jupiter's moon Europa to try to answer that question. 17"A future mission to Uranus is crucial to understanding not only the planet and magnetosphere, but also its atmosphere, rings and moons," Jasinski said. 18I'm Caty Weaver. 19Will Dunham reported this story for Reuters. Jill Robbins adapted it for Learning English. 20___________________________________________ 21Words in This Story 22nebula - n. a cloud of gas or dust in space that can sometimes be seen at night 23aurora (_ borealis, or Northern Lights) - n. large areas of green, red, blue, or yellow light that sometimes appear in the night sky in far northern regions 24occur - v. to happen 25peak - adj. at the highest point or level 26detect - v. to discover or notice the presence of (something that is hidden or hard to see, hear, taste, etc.) 27prime - adj. most important 28crucial - adj. very important 29What do you think of this story? Write to us in the Comments Section.