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Nasa spacecraft achieves milestone by ‘touching’ Suns surface. Details here

Nasa spacecraft achieves milestone by ‘touching’ Suns surface. Details here

A spacecraft launched by the National Aeronautics and Space Administration (Nasa) has achieved what was once thought impossible. For the first time in history, a spacecraft officially “touched the sun, plunging through the unexplored solar atmosphere known as the corona, an extreme environment thats roughly 2 million degrees Fahrenheit. The Parker Solar Probe successfully entered the corona of the Sun in April during the spacecraft’s eighth close approach to the sun. Scientists said it took a few months to get the data back and then several more months to confirm. A scientific paper describing the milestone was published in the Physical Review Letters. How was the feat made possible? The historic moment was achieved thanks to a large collaboration of scientists and engineers, including members of the Center for Astrophysics | Harvard & Smithsonian (CfA) who built and monitor a key instrument on board the probe: the Solar Probe Cup. The cup collects particles from the Suns atmosphere that helped scientists verify that the spacecraft had indeed crossed into the corona. The goal of this entire mission is to learn how the Sun works. We can accomplish this by flying into the solar atmosphere, said Michael Stevens, an astrophysicist at the CfA who helps monitor the cup. ☀️ Our #ParkerSolarProbe has touched the Sun!For the first time in history, a spacecraft has flown through the Suns atmosphere, the corona. Heres what it means: https://t.co/JOPdn7GTcv #AGU21 pic.twitter.com/qOdEdIRyaS A spacecraft launched by the National Aeronautics and Space Administration (Nasa) has achieved what was once thought impossible. For the first time in history, a spacecraft officially “touched the sun, plunging through the unexplored solar atmosphere known as the corona, an extreme environment thats roughly 2 million degrees Fahrenheit. The Parker Solar Probe successfully entered the corona of the Sun in April during the spacecraft’s eighth close approach to the sun. Scientists said it took a few months to get the data back and then several more months to confirm. A scientific paper describing the milestone was published in the Physical Review Letters. How was the feat made possible? The historic moment was achieved thanks to a large collaboration of scientists and engineers, including members of the Center for Astrophysics | Harvard & Smithsonian (CfA) who built and monitor a key instrument on board the probe: the Solar Probe Cup. The cup collects particles from the Suns atmosphere that helped scientists verify that the spacecraft had indeed crossed into the corona. The goal of this entire mission is to learn how the Sun works. We can accomplish this by flying into the solar atmosphere, said Michael Stevens, an astrophysicist at the CfA who helps monitor the cup. |#+| “The only way to do that is for the spacecraft to cross the outer boundary, which scientists call the Alfven point. So, a basic part of this mission is to be able to measure whether or not we crossed this critical point, he added. The corona is the outermost layer of the Suns atmosphere where strong magnetic fields bind plasma and prevent turbulent solar winds from escaping. The Alfven point is when solar winds exceed a critical speed and can break free of the corona and the Suns magnetic fields. Prior to 28 April, the spacecraft had been flying just beyond this point. If you look at close-up pictures of the Sun, sometimes youll see these bright loops or hairs that seem to break free from the Sun but then reconnect with it, Stevens explained. Thats the region weve flown into -- an area where the plasma, atmosphere and wind are magnetically stuck and interacting with the Sun. According to data collected by the cup, the spacecraft entered the corona three times on 28 April, at one point for up to five hours. Instrument used CfA astrophysicist Anthony Case, the instrument scientist for the Solar Probe Cup, says the instrument itself is an incredible feat of engineering. The amount of light hitting the Parker Solar Probe determines how hot the spacecraft will get, Case explained. While much of the probe is protected by a heat shield, our cup is one of only two instruments that stick out and have no protection. Its directly exposed to the sunlight and operating at a very high temperature while its making these measurements; its literally red-hot, with parts of the instrument at more than 1,800 degrees Fahrenheit [1,000 degrees Celsius], and glowing red-orange. To avoid degradation, the device is constructed of materials that have high melting points, like tungsten, niobium, molybdenum and sapphire. How will it help research? But the success of the Parker Solar Probe represents much more than technological innovation. There are many mysteries about Earths closest star that scientists are hoping the probe can help solve. For example, We dont actually know why the outer atmosphere of the Sun is so much hotter than the Sun itself, Stevens said. The Sun is 10,000 degrees Fahrenheit [5,500 degrees Celsius], but its atmosphere is about 3.6 million degrees Fahrenheit [2 million degrees Celsius]. He added, We know that the energy comes from the churning magnetic fields bubbling up through the surface of the sun, but we do not know how the Suns atmosphere absorbs this energy. In addition, outbursts from the Sun, like solar flares and high-speed solar winds, can have a direct impact on Earth, disrupting power grids and radio communication. The Parker Solar Probe can help better understand all these phenomena as it continues to orbit the Sun and take measurements and data for scientists to analyze here on Earth. The plasma around the Sun can act as a laboratory that teaches us about processes taking place in almost every astronomical object across the entire universe, Case said. Download.

science 2021-12-15 Livemint