Voyager 1 reaches One Light-Day from Earth

Why in News?

NASA’s Voyager 1 spacecraft, the farthest human-made object in history is crossing a monumental cosmic milestone by reaching a distance of one light-day from Earth.

• Launched on - September 5, 1977.
• The threshold represents the distance that a particle of light travels through a vacuum in 24 hours - approximately 16.094 billion miles (25.902 billion kilometers) or about 173 astronomical units (AU).
• Communication Lag- At a distance of one light-day, any command transmitted from NASA’s Deep Space Network takes a full 24 hours to reach the probe, and the corresponding telemetry data takes another 24 hours to travel back, resulting in a 48-hour round-trip communication delay.
• Interstellar Explorer - Crossed the heliopause into interstellar space in 2012.
• Voyager 1 continues to gather sparse plasma and magnetic field data despite operating on a dwindling power supply from its decaying plutonium-238 radioisotope thermoelectric generators.
• Current Operating Region - Interstellar Space (beyond the heliosphere boundary).
• Power Source- Radioisotope Thermoelectric Generators (RTGs) losing ~4 watts annually.
• Global Celebrations - NASA organized public outreach initiatives, including a global "Shine Bright for Voyager's Light-Day" campaign inviting space enthusiasts to flash Voyager’s historic call sign (V-G-R) in Morse code using smartphone lights.
• Cosmic Distances via Light Travel Time
  • The Moon: ~1.3 seconds away
  • The Sun: ~8 minutes and 19 seconds away (1 AU)
  • Neptune: ~4 hours away
  • Voyager 1: 24 hours (1 Light-Day) away
  • Proxima Centauri (Nearest Star System)- ~4.24 light-years away (~1,550 days of continuous travel at light speed)
• The Golden Record - Both Voyager spacecraft carry a gold-plated phonograph record containing sounds, scientific data, spoken greetings in 55 languages, and musical selections representative of Earth's culture and biodiversity.

Reference

NASA | Voyager 1 One-Light Day Activities