NASA’s Midas Touch: Parker Probe Touching The Sun

In Greek mythology, Icarus was the son of an architect called Daedalus. They wanted to escape from the island of Crete since the king had imprisoned them for sharing their secrets. Daedalus had constructed wings from birds’ moulted feathers and some other materials. He had used the beeswax for the ‘construction’ of the wings. Daedalus had warned his son that he should not fly too high. But Icarus became overambitious and flew too close to the Sun. The heat melted the wax in his wings, and he drowned in the sea. The myth gave rise to the phrase, "fly too close to the sun." Metaphorically, this means that taking excessive risks or becoming overambitious is incorrect. Interestingly, on December 24, 2024, the US space agency NASA did the same and looks to have succeeded with the ambition of touching the Sun!

NASA's Parker Solar Probe has made history with the closest flyby to the Sun. To date, no spacecraft has gone so close to the Sun. Exact details about the success of this flyby would be known after a few days since NASA lost contact with the spacecraft for some days owing to its proximity to the Sun. A flyby mission means a spacecraft passing in proximity to another body.  This mission is designed so that the flyby spacecraft passes close to another planet/star but is not captured into an orbit by gravity. Incidentally, various flyby missions have happened for multiple planets in space, but closing on to the Sun is unbelievable. The first flyby on the Moon was done by the Soviet probe Luna 1 on January 4, 1959.

Studying the Sun is essential since it is the origin of space weather. Various activities are happening on the solar surface and its vicinity.  The Sun emits electromagnetic energy across various wavelengths, and the knowledge of this is essential in the prediction of solar weather. The Sun also releases a stream of charged particles, known as plasma, which forms the solar wind. Irregularly, massive explosions on the Sun happen, which cause energy bursts that direct plasma and radiation towards the Earth. Solar flares, coronal mass ejections (CMEs), and solar prominence events are instances of solar phenomena responsible for these bursts. CMEs drive geomagnetic storms, and solar flares result from such explosive events on the Sun that release high-energy particles and radiation. These solar events become the basis of atmospheric drag, leading to a gradual decrease in the altitude of satellites in the Low Earth Orbit (LEO). Such storms also severely disrupt radio communications and cause damage to long-distance power transmission lines. Aircraft passengers and crew may also get exposed to radiation, especially on polar flight routes.

A recent example of solar storms impacting the health of satellites is the storm in February 2022. During this month, 49 Starlink satellites were launched, and the very next day, a geomagnetic storm increased the atmosphere's density, unexpectedly increasing the drag force on the satellites. This made 40 of 49 satellites unusable. In May 2024, satellite systems had an impact due to the most significant geomagnetic storm due to solar activity in two decades. The earlier such storm was witnessed in 2003. All this indicates how important it is to study the behaviour of the Sun.

On December 24, 2024, the Parker Probe completed its closest flyby within just 6.1 million km of the Sun's surface. This marks a crucial moment in space science, as it will likely provide unique data about the Sun's magnetic fields, solar wind, and coronal heating. Launched in 2018, the Parker Solar Probe was designed to get closer to the Sun than any spacecraft before it, to study its corona (the Sun's outer atmosphere) and understand its behaviour and influence on the solar system.

This spacecraft is known to have experienced temperatures above 980 degrees Celsius or more. The craft travels around 690,000 km (say around 200 km in one second). Such high speeds are maintained to ensure the craft is in a high-temperature zone only for a fraction of a second. Before the closed flyby, the Parker Solar Probe had done 21 flyby to the Sun. The following two would be on March 22 and June 19, 2025. They also would be having similar close encounters with the Sun.

There are various sensors (instruments) onboard the Parker Probe.  The Electromagnetic Fields Investigation instrument captures the scale and shape of electric and magnetic fields in the Sun's atmosphere. Integrated Science Investigation of the Sun is meant to measure particles across a wide range of energies. This instrument will try to understand the particles' lifecycles by measuring electrons, protons and ions. Also, there is a wide-field imager for solar probes, which are optical telescopes that acquire images of the corona and inner heliosphere. Then there are Solar Wind Electrons, Alphas and Protons) for counting the electrons, protons, and helium ions and measuring their velocity, density, and temperature properties.

The spacecraft's instruments have captured detailed measurements of the solar wind and energetic particles, which could help scientists understand space weather phenomena and improve our ability to predict solar storms that can impact Earth. These findings have important implications for space exploration and technological systems on Earth, particularly in telecommunications and satellite infrastructure.

Parker Solar Probe's close encounters with the Sun will continue for several years. The mission’s life will be around seven years, and it would be interesting to know how much this mission adds to our understanding of the Sun and its dynamic processes.