![]() ![]() ![]() This is why L1, L2, and 元 don't "collect" objects like L4 and L5 do. ![]() However, L1, L2, and 元 are metastable so objects around these points slowly drift away into their own orbits around the Sun unless they maintain their positions, for example by using small periodic rocket thrust. Some small asteroids are known to be orbiting the Sun-Earth L4 and L5 points. In fact, L4 and L5 are stable in that objects there will orbit L4 and L5 with no assistance. Some Technical Details: It is easy for an object (like a spacecraft) at one of these five points to stay in place relative to the other two bodies (e.g., the Sun and the Earth). The L1, L2, and 元 points are all in line with each other - and L4 and L5 are at the points of equilateral triangles. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. Joseph-Louis Lagrange was an 18th century mathematician who found the solution to what is called the “three-body problem.” That is, is there any stable configuration, in which three bodies could orbit each other, yet stay in the same position relative to each other? As it turns out, there are five solutions to this problem - and they are called the five Lagrange points, after their discoverer. This is why the telescope is out at the second Lagrange point. To have the sunshield be effective protection (it gives the telescope the equivalent of SPF one million sunscreen) against the light and heat of the Sun/Earth/Moon, these bodies all have to be located in the same direction. The temperature difference between the hot and cold sides of the telescope is huge - you could almost boil water on the hot side, and freeze nitrogen on the cold side! The telescope itself operates at about 225 degrees below zero Celsius (minus 370 Fahrenheit). Translation of an original article published in French on the publisher may only be liable for the French version.+ The temperature difference between the hot and cold sides of the telescope is huge - you could almost boil water on the hot side, and freeze nitrogen on the cold side! During a previous observation, focused on Enceladus, astronomers discovered a large plume of water vapor rising from the Moon's south pole. On Saturn's left, three small dots stand out, representing three of the planet's many satellites: from top to bottom, Dione, Enceladus and Tethys. By contrast, the rings, composed mainly of water ice, are much brighter, even if some of them are too faint to be seen on the image. In the image transmitted on June 25, the ringed planet appears particularly dark, which is due to the fact that the telescope observes in the infrared: at this wavelength, the sunlight received by Saturn is partly absorbed by the methane present in small quantities in its atmosphere. ![]() The James Webb Space Telescope, which will celebrate the first anniversary of its inaugural image on Wednesday, July 12, recently turned its attention to Saturn for the first time in its short life. Image of Saturn transmitted on June 25 by the James-Webb telescope. Le Monde Published on July 11, 2023, at 10:01 am (Paris), updated on July 11, 2023, at 10:01 am Lire en français One year after its launch, the James Webb Space Telescope turned its attention to Saturn for the first time. The James Webb telescope's first photo of Saturn ![]()
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