Chapter 1: The Journey to the Sun

The Parker Solar Probe, a compact NASA spacecraft, is on a groundbreaking mission to study the sun up close. As it approaches the sun, it endures extreme heat and intense solar radiation, preparing to enter the star's outer atmosphere and experience temperatures nearing 2 million degrees Fahrenheit (over 1 million degrees Celsius).

To withstand these harsh conditions, Parker is equipped with a robust, specially designed shield that safeguards its scientific instruments, along with a water-cooling system. Inside the probe, conditions remain comfortable at 78 degrees Fahrenheit (26 degrees Celsius). Since its launch last summer, Parker has completed three close passes of the sun, with many more to come in the next five years. The data gathered has already begun to challenge scientists' expectations.

One of the most pivotal discoveries in astronomy is that Earth is not the center of the universe; rather, it orbits the sun. Since Copernicus's revolutionary ideas, scientists have made significant strides, utilizing telescopes, satellites, and spacecraft to explore the solar system. They’ve uncovered the nuclear fusion that fuels our sun and recognized that many stars could potentially be someone else's sun. Despite these advancements, our knowledge of the sun's intricate workings remains incomplete.

Curiosity about the sun's mysteries is akin to engaging with an inquisitive child. Questions abound: Why is the sun's corona so much hotter than its surface? What is the origin of the solar wind? Why does it erupt so dramatically from the corona? What causes solar flares that eject particles into space? These are the enigmas that researchers hope the Parker Solar Probe will elucidate before its mission concludes in 2025, culminating in a daring dive into the sun.

NASA recently unveiled initial findings, published in four papers in Nature, stemming from measurements taken of the corona—an area remarkably hotter than the sun’s surface. This outer layer extends millions of miles into space and is only visible during a solar eclipse, when the moon obscures the sun and reveals a glowing halo against the dark sky.

The corona emits potent streams of high-energy particles known as solar wind, which permeate the solar system, reaching far beyond Pluto. Data from the Parker probe indicates that solar wind is significantly more turbulent near the sun than in the regions we inhabit, tens of millions of miles away. The solar wind carries the sun’s magnetic field into space, occasionally causing the magnetic forces to flip direction momentarily, pointing back toward the sun rather than extending outward. Researchers were surprised by both the intensity and frequency of these occurrences.

Additionally, scientists discovered that variations in the sun's magnetic field accelerate particles escaping from the sun at rates far exceeding their predictions. Despite decades of investigation into distant stars, some billions of light-years away, our sun continues to conceal its secrets.

Previous instruments on Earth and earlier solar missions were unable to achieve such close observations. Proximity is critical for studying the sun. As Stuart Bale, a scientist at the University of California, Berkeley, explains, "Imagine living halfway down a waterfall while trying to understand its source. It's difficult to discern without being closer." The Parker probe brings us closer to the sun than ever before.

Each close encounter also presents Parker with one of the greatest challenges in robotic space exploration. Although it seems paradoxical, reaching the sun is more complex than exiting the solar system. The sun's gravitational pull influences everything nearby, causing celestial bodies to orbit at high speeds that prevent them from falling into it. Yanping Guo, the mission's design and navigation manager, clarifies, "To reach Mars, you only need a slight increase in speed. To get to the sun, you must significantly reduce your current momentum."

Currently, no rocket technology can sufficiently counteract Earth's motion, so the Parker probe uses gravity assists from Venus. By orbiting Venus, it gradually sheds some of Earth's momentum, drawing itself closer to the solar center.

This mission honors Eugene Parker, the astrophysicist who first proposed the dynamics of solar wind in 1958. Initially met with skepticism, his theory gained credibility as NASA deployed robotic spacecraft into the solar system, confirming his predictions. Robotic missions have since followed solar wind as far as possible, with a 2013 Voyager probe detecting solar wind particles mingling with cooler interstellar particles—where conditions are a different kind of harsh.

The first video, "The Sun is NOT the Center of the Solar System," explores the historical shift in our understanding of the solar system's structure, focusing on how we came to recognize the sun's role and its actual position.

The second video, "Hidden Mysteries of Our Solar System," delves into the ongoing discoveries and the enigmatic aspects of our solar system that scientists continue to investigate.