Amateur astronomers pinpoint Voyager 1 with a vintage 1950s telescope. after a bug

Voyager 1 is currently exploring interstellar space at a distance of 15.5 billion miles (24.9 billion kilometers) from Earth. Communicating with the most distant man-made object can be a challenge, but not for a telescope that is designed to listen to lower frequencies emitted from space.

A team of amateur astronomers used the Dwingeloo radio telescope in the Netherlands to receive signals from Voyager 1 after a communications problem forced the spacecraft to rely on a backup transmitter. Dwingeloo, built in the 1950s, joins an elite group of telescopes capable of detecting Voyager’s weak radio signals from deep space, a critical capability when NASA’s antennas cannot communicate with the spacecraft.

In late October Voyager 1 suddenly turned off one of his radio transmittersforcing the mission team to rely on a backup unit—a weaker transmitter that had not been used since 1981. Voyager’s second radio transmitter, called S-band, transmits a much weaker signal than its X-band transmitter. The NASA team wasn’t sure the S-band signal could be detected because the spacecraft is much further away today than it was 43 years ago. NASA uses the Deep Space Network to communicate with its spacecraft, but the global array of giant radio antennas is optimized for higher-frequency signals.

The Dwingeloo telescope, on the other hand, is designed to observe lower frequencies than the 8.4 gigahertz telemetry transmitted by Voyager 1, according to CA Muller Radio Astronomy Station. Dwingeloo would normally not be able to detect signals transmitted by Voyager 1 because the antenna mesh is less reflective at higher frequencies. However, when Voyager 1 switched to a lower frequency, its messages fell into Dwingeloo’s frequency band. In this way, astronomers took advantage of the spacecraft’s communication problem to listen to its weak signals to NASA.

Astronomers used orbital predictions of Voyager 1’s position in space to correct for the Doppler frequency shift caused by Earth’s motion as well as the spacecraft’s motion in space. The faint signal was detected live, and further analysis later confirmed that it matched Voyager 1’s position.

Fortunately, the mission team at NASA turned Voyager 1’s X-band transmitter back on in November and is currently performing several remaining tasks to return the spacecraft to its normal state. Fortunately, radio telescopes like Dwingeloo can help fill in the gaps while NASA’s communications array has trouble reaching its spacecraft.

The iconic Voyager 1 is feeding scientists valuable data about the solar system and beyond for decades. On its way into interstellar space, the probe had close encounters with Jupiter and Saturn and discovered two Jovian moons, Thebes and Metidas, as well as five new moons and a new ring called the G-ring around Saturn.