Parker Solar Probe is so fast it turns any space dust into plasma

Parker Solar Probe is so fast it turns any space dust into plasma
Photo Credit: NASA Jet Propulsion Laboratory
11 Nov, 2021

The Parker Solar Probe, NASA’s first foray into approaching the Sun, is already distinguished as the fastest human made object, ever. Now, scientists have discovered how the probe’s hypervelocity speed interacts with space debris. The latest study will help the scientists better understand requisites for future solar probes as well as how plasma regions in atmospheres of other planets interact with solar wind. Case in point – how space debris collide against the heat shield of the Parker Solar Probe, and ionise as a result in the zodiacal cloud.

Through electromagnetic and optical observations made by instruments aboard the Parker Solar Probe, the scientists learnt that hypervelocity collisions with space dust is creating a massive amount of heat. This heat first vaporizes the dust, and subsequently ionises the dust – leaving a trail of plasma behind. Plasma is a material that comprises ions and electrons broken up from atoms of any element, as a result of a reaction. These collisions occur at hypervelocity speeds of close to 10,800 kilometres per hour.

The dust grains in question resides within the zodiacal cloud, which is a stretch of thick dust and debris that are left behind by asteroids and comets. This stretches through our entire solar system, but is the thickest in the Sun’s vicinity. The main point of contention here is that these collisions – with the Parker Space Probe and dust particles sized less than 20 microns in diameter – create tiny plasma explosions on the surface of the spacecraft. As the probe travels away, the remainder debris from the collision expands away from the probe itself.

The study was conducted by a team led by David Malaspina, researcher at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder. The team used antennas and magnetic field sensors aboard the Parker Solar Probe to measure the disturbances that this phenomenon creates. This study can have a major impact on the safety of this space probe as well as future ones. For instance, the collisions knock metallic chips and paint into space, which scatter the sunlight and temporarily blind the Parker probe – something that can prove catastrophic for it. The spacecraft relies on accurate orientation of its heat shield, enabled by its navigational cameras, to be able to operate safely.

The study can also help understand how plasma belts behave when exposed to solar wind, thereby offering scientists further data and insights into how the atmosphere of planets close to their stars interact with the gravitational forces. This factor can further help scientists prepare for interstellar probes in the distant future.

The full results of the study will be presented today, November 11, at the 63rd annual meeting of the American Physical Society (APS)’s Division of Plasma Physics.