The Hindu: Published on 31st March 2025:
Why in News?
NASA’s Parker Solar Probe made another close approach to the Sun on March 22, 2024, reaching within 6 million km of its surface. This continues the probe’s mission to study the Sun’s corona and its influence on the solar system. The probe, launched in 2018, has been making progressively closer orbits, with another approach scheduled for June 19, 2024.
Background
The Parker Solar Probe was launched on August 12, 2018, aboard a Delta IV Heavy rocket from Cape Canaveral, Florida. The probe was designed to study the Sun’s outer atmosphere (corona) and the dynamics of solar wind. To achieve this, it uses Venus flybys to gradually lower its orbit and move closer to the Sun. The mission is expected to continue until 2025, with 24 close approaches planned.
Objectives of the Mission
- Understand the heating of the Sun’s corona – Why the corona is hotter than the Sun’s surface.
- Investigate solar wind acceleration – How solar wind particles are ejected at high speeds.
- Examine solar storms and their impact on Earth – Understanding solar flares and coronal mass ejections (CMEs).
- Study space weather’s effect on Earth and satellites – Preventing communication failures and power grid disruptions.
Scientific Significance
- The Sun’s magnetic field undergoes rapid changes, causing solar flares and storms.
- Solar storms can disrupt telecommunication, navigation systems, power grids, and satellites.
- The Parker Solar Probe has discovered dust-free pockets near the Sun and magnetic switchbacks (areas where the solar wind’s magnetic field bends abruptly).
- It has provided insights into Alfvén waves, which may explain why the solar corona is hotter than the Sun’s surface.
Technology and Engineering Feats
Heat Shield: An 8-foot-wide carbon-composite shield protects the probe, maintaining an internal temperature of 29°C despite external temperatures reaching 1,370°C.
Speed: The probe travels at 692,000 km/hr, making it the fastest human-made object.
Scientific Instruments:
FIELDS: Measures electric and magnetic fields in the corona.
ISoIS: Observes high-energy particles from solar storms.
SWEAP: Studies the density and speed of solar wind particles.
WISPR: Captures images of the Sun’s outer layers.
Faraday Cup: Measures ions and electrons in solar wind.
Challenges of the Mission
Heat and Radiation: The Sun emits extreme heat and radiation, requiring advanced shielding.
Orbital Adjustments: The probe had to slow down significantly to avoid being pulled into the Sun’s gravitational well.
Extreme Speed: Maintaining instruments at a constant position while traveling at nearly 700,000 km/hr.
Global Collaborations
NASA’s Parker Solar Probe works alongside India’s Aditya-L1 mission, which observes the Sun from 1.5 million km away at the L1 Lagrange point.
Together, these missions aim to improve space weather predictions, which will help protect satellites, astronauts, and communication networks.
Conclusion:
The Parker Solar Probe is revolutionizing our understanding of the Sun’s atmosphere and solar wind dynamics. Its findings are critical for understanding space weather, protecting Earth’s technology, and answering fundamental questions about solar physics. The upcoming approach on June 19, 2024, will provide further insights into the Sun’s behavior and its impact on our solar system.
