NASA achieves record-breaking close approach to the Sun

The spacecraft ventured into the corona, the Sun’s outer atmosphere, where temperatures exceed several million degrees Celsius, yet it remained operational and sent vital data back to Earth.

Mission overview

Launched in August 2018, the Parker Solar Probe was designed to study the Sun’s properties and behaviour at unprecedented proximity. The mission’s key objectives include:

• Tracing the energy that heats the solar corona and accelerates the solar wind.
• Determining the structure and dynamics of plasma and magnetic fields at the origins of the solar wind.
• Investigating mechanisms that accelerate and transport energetic particles.

Over the course of its mission, the probe has used Venus’s gravity to progressively narrow its orbit around the Sun. This latest perihelion, or closest approach, represents a critical milestone in its planned 24 orbits.

Engineering feats to withstand extreme conditions

To endure the Sun’s intense heat and radiation, the Parker Solar Probe is equipped with a cutting-edge Thermal Protection System. This heat shield, made of carbon-composite materials, allows the spacecraft to withstand temperatures exceeding 900°C on its sun-facing side, while maintaining its instruments at a safe temperature of around 30°C.

The probe carries four main scientific instrument suites:

• FIELDS: Measures electric and magnetic fields.
• WISPR: Captures images of the solar corona and solar wind.
• SWEAP: Analyses particles in the solar wind.
• ISʘIS: Studies high-energy particles.

Significance of the mission

This mission holds profound implications for understanding our closest star. Scientists are particularly focused on two long-standing mysteries:

• Why is the corona hotter than the Sun’s surface? The Sun’s surface averages 5,500°C, but the corona reaches millions of degrees.
• How is the solar wind accelerated? Solar wind is a stream of charged particles that impacts Earth’s magnetic field, potentially causing geomagnetic storms.

Understanding these phenomena is essential for predicting space weather, which can disrupt satellites, power grids, and communications systems on Earth.

Milestones and future goals

The Parker Solar Probe has already provided critical data, including insights into solar wind dynamics and the origins of solar flares. With its latest close approach, the spacecraft has set a new record, surpassing its own earlier achievements.

NASA confirmed the spacecraft’s operational status after this close encounter through a “proof of life” signal. The next batch of detailed data is expected to arrive by 1st January 2025, further enriching our knowledge of solar processes.

The Parker Solar Probe’s mission is set to continue through 2025, with even closer encounters planned. By the mission’s conclusion, the spacecraft is expected to come within 3.83 million miles (6.16 million km) of the Sun, travelling at speeds up to 430,000 mph (700,000 km/h).

A leap forward in heliophysics

The Parker Solar Probe represents a monumental step in heliophysics, allowing scientists to observe the Sun’s activities in ways previously thought impossible. This data will not only solve fundamental mysteries about the Sun but also aid in protecting modern infrastructure from the effects of solar activity.

NASA’s efforts with the Parker Solar Probe underscore humanity’s pursuit of knowledge and the technological ingenuity required to explore the most extreme environments in our solar system.