NASA transmits its first signal from interstellar space

NASA's Voyager 2 helps scientists determine where to end the influence of the solar wind and start interstellar space.

In a study published in the journal Nature Astronomy, NASA scientists discovered that there is a heliosphere buffer, where hot solar winds come into contact with cold interstellar space. The team in the project compares data transmitted from the device on Voyager 2 and determined the time the ship passes through this buffer zone was November 5, 2018, when particles in the solar wind around the probe subsided. . This indicates that the Voyager 2 has left the heliosphere, a bubble-filled buffer created by the solar wind.

Voyager 1 and 2 in the interstellar space.(Photo: NASA).

The new study reveals that Voyager 2 travels through the heliosphere in less than a day and is more than 17.7 billion km from the Sun. The aircraft flies through the heliosphere from the low-density plasma region of solar wind to the high-density cold plasma region of interstellar space. In between these two distinct regions there is an equilibrium, where uniform plasma density helps balance the pressure difference.

On November 5, 2018, NASA's Voyager 2 spacecraft became the second artificial object to enter interstellar space, after Voyager 1. Two ships leave the heliosphere but have not yet been out of the solar system. The system boundary lies at the outer edge with the Oort cloud, a cluster of small objects influenced by the gravity of the Sun. Scientists predict the Voyager will take 2,300 years to reach the inner edge of the cloud, and 3,000 years to fly through it.

The Voyager 1 entered interstellar space in 2012, but the plasma onboard was broken and was unable to provide complete data on the passage through the heliosphere. From the data collected by Voyager 1 and Voyager 2, the scientists found particles in the solar wind and wind in interstellar space along the boundary. The wind from interstellar space was created by stars that became supernovas millions of years ago. The mixing of the two particles creates a layer between the heliosphere and interstellar space.

Based on the voyage 2's voyage, the team discovered that the heliosphere had a clear boundary between the two plasmas. They also noted the strong interstellar magnetic field, which originated from exploding stars. The interaction between the Sun and interstellar space also attracts scientists. Shock waves from the Sun go straight through the heliosphere to the interstellar medium and cause disturbances, similar to the effects of a supernova explosion.

Both Voyager 1 and 2 launched into space in 1977 to explore planets in the solar system, designed to last five years but have operated for 42 years. Scientists can still keep in touch with the Voyager 2 even in interstellar space, but the data takes about 16.5 hours to transfer to Earth. With the new plan to save energy and guide the ship, the project engineering team hopes the Voyager 1 and 2 will transmit data for at least the next few years. The data collected will provide information for NASA's Acceleration and Interstellar Mapping probes, scheduled for launch in 2024.