Voyager Mission

The Voyager Mission is an American program launched in 1977, to study the planetary systems of Jupiter, Saturn, Uranus, and Neptune by employing two robotic space-probes, Voyager 1 and Voyager 2.

Key Points

• The mission has been extended three times and they continue to transmit several useful scientific data.
• In 2012, the Voyager 1 became the first man-made object to enter interstellar space by traveling further than anything/anyone in history.

Voyager finds a new type of electron burst

• A detailed analysis of recent data from Voyager 1 and Voyager 2 has revealed the first bursts of cosmic ray electrons in interstellar space.
• The bursts of cosmic rays are detected from the Sun, more than 23 billion kilometers away. These energized particles accelerate beyond the borders of the powerful winds of the Sun.
• Sun’s surface emits solar wind i.e. a stream of charged particles in the form of plasma continuously. This stream generates a magnetic field.
• This stream or solar wind travels every planet and object in our Solar System and sprinkles out into the interstellar medium.
• Beyond the magnetic field of the Sun, in the cold of interstellar space, what happens to the solar plasma and cosmic rays is not clear.
• The Voyager probes give us a chance to find out more. Astronomers are proposing a new model to check what happens to shockwaves in interstellar space.
• As detected by Voyager, when an energy wave followed by plasma reaches interstellar space, the shock wave pushes higher-energy cosmic rays to hit the magnetic field generated by the wave, and another shock reflects and pushes them into the higher energy state.
• The plasma then heats up the low-energy electrons that propagate along magnetic fields.
• This upstream region that is being called ‘the cosmic-ray foreshock’ is assumed to occur just behind the magnetic field line of interstellar space.
• As per the conclusion of the study, bursts of high-energy electrons arise from the reflection (and acceleration) of cosmic-ray electrons at the first contact of the shock with the interstellar magnetic field line passing through the spacecraft.

The findings of the study were published in the Astronomical Journal.