Doctor Luis Campusano
Professor of the Department of Astronomy at the Faculty of Physical and Mathematical Sciences from the University of Chile
Researcher at the Center for Excellence in Astrophysics and Associated Technologies
The first results from the Parker Solar Probe – whose journey to the Sun began at Cape Canaveral, Florida, on Sunday 12th August 2018 – were recently published in scientific journal Nature, thus allowing us to forecast space climate events that might severely impact on energy and communications transmission on the Earth.
NASA’s Parker Solar Probe, with a price tag of US$1.5 billion, is accomplishing a historical mission by flying for the first time through the Sun’s external atmosphere (the corona), at a temperature millions of degrees higher than the Sun’s surface, which can be observed when a total Sun eclypse occurs. The spacecraft’s name honours Eugene N. Parker, retired astrophysicist from the University of Chicago who was the first to predict the solar wind, a current of charged particles, principally protons and electrons, that conitnuously flow out of the Sun and into the Solar System at a speed of approximately 1.6 millions kilometres per hour. For humankind, fortunately, the Earth’s magnetic field generates a bubble that deviates the solar wind around our planet and produces the beautiful auroras displaying during nighttime at polar regions.
The main scientific goal of the Parker mission is to understand how the solar corona is heated and how solar wind is accelerated. For this goal, it will spend almost seven years assessing magnetic fields and components of solar wind on-site. New data from solar activity will crucially increase our capacity to forecast space climate events that might severely impact on energy and communications transmission on the Earth.
The Parker Solar Probe, in its closest approaches to the Sun, faces heat and radiation like no spacecraft did before. While the facing side of its solar shield will reach temperatures up to 1000°C, its extraordinary design helps to keep its useful load at an ambient temperature closer to 20°C. On its latest three orbits, the Parker Solar Probe will orbit at less than 9 radii (solar ratio is 696.000 kilometres, around 110 times larger than the Earth’s ratio) from solar surface, that is to say, at less than 6.26 million kilometres.
In 2017, the mission was renamed after Eugene Parker, Emeritus Professor at the Department of Astronomy and Astrophysics from the University of Chicago. In the 1950s, the scientist proposed a series of concepts on how stars, including the Sun, emit energy. Parker called this energy flow ‘solar wind’, and described it as a complex system of plasma, magnetic fields and high energy particles. Parker also theorised an explanation on the corona’s overheating, which is opposed to what’s expected for the laws of physics, as the external layers of solar surface were colder.
Historical results
On the four articles published in Nature, the Sun is revealed with astonishing details which might be found in other stars and also change our current ideas about the processes of star formation in general. The Parker Solar Probe reveals characteristics of our star previously unknown and whose existence only had theoretical support.
The findings of this space mission on how the Sun constantly emits matter and energy, might help scientists to reconsider current models of the Sun used for predicting space climate surrounding our planet. This information will be of crucial importance to protect astronauts and technology in space, including an important part of NASA’s Artemis Program, which will send the first woman and the next man to the Moon, possibly by 2024, and will serve to prepare future human missions to Mars.
The four articles, now available online in Nature journal, describe unprecedented observations by the Parker Solar Probe around the Sun through two previous flybys. They reveal new information on the processes that generate solar wind and how the mentioned phenomenon is combined with solar rotation. Through these flybys, the mission also examined the dust of coronal loops and detected events of particle acceleration so small to be undetectable from the Earth (almost 150 million kilometres from the Sun).
When seen from the Earth, solar wind plasma looks like a relatively uniform flow, one that can interact with our planet’s own magnetic field and cause space climate effects interfering technology more or less intensively. However, from the vicinity of the Sun, observations of the Parker Solar Probe reveal a dynamic and highly structured system, similar to an estuary serving as transition zone when a river flows into the ocean. For the first time, scientists can study solar wind from its source itself, the solar corona, in a similar way to how we can observe flows serving as sources of a river. The new perspective bri¿ought by the Parker Solar Probe will help solve the mysteries set out by the Sun and find protection paths for our little Earth (with a mass 333.000 times smaller than the Sun).
This early information from the Parker Mission show our star, the Sun, from an unimaginable perspective. Stars are bodies hard to imagine; the observation of the Sun dramatically shows us the type of monster they are. By having a spacecraft so close to the Sun, at a distance equal to a third of the distance that separates it from Mercury, instead of doing it from a much larger distance, continuously sending data to the Earth about its environment, we are building an unprecedented vision of the important solar phenomena and how they affect us at the Earth. It’s just the beginning of an incredible story that will end in 2025. This will definitely bring a lot to talk about and will contribute to security in space research and humankind. Stay alert.
Luis Campusano, researcher at the Department of Astronomy from the University of Chile and co-organiser of the 354th International Astronomical Union Symposium on the Sun (Copiapó, Chile, 2019), tells the story.
Articles published in Nature can be found in this link: https://www.nasa.gov/feature/goddard/2019/nasas-parker-solar-probe-sheds-new-light-on-thesun
Sounds of the solar wind detected by the Parker Solar Probe can be seen in the next video: