NASA’s Voyager 1 spacecraft will become the first human-made object to reach a distance of one light-day from Earth on Nov. 18, marking another milestone in its nearly 50-year journey through interstellar space.
By yourNEWS Media Newsroom
WASHINGTON — NASA’s Voyager 1 spacecraft is expected to reach a distance of one light-day from Earth on Wednesday, Nov. 18, becoming the first human-made object to travel far enough that a radio signal moving at the speed of light takes 24 hours to reach it.
The spacecraft will be approximately 16.094 billion miles (25.902 billion kilometers) from Earth when it reaches the milestone at 5:16:07 a.m. Eastern time, according to NASA’s Voyager mission tracking information.
Launched Sept. 5, 1977, Voyager 1 has traveled farther than any other human-made object. Originally designed to study Jupiter and Saturn, the spacecraft has continued operating for more than 49 years and remains active in interstellar space.
The milestone represents a distance rather than a travel time. A light-day is the distance light travels in 24 hours, meaning a command transmitted from Earth will take an entire day to reach Voyager 1. Any response will require another 24 hours to return, creating a minimum two-day communication cycle.
“If you want to say ‘hello’ to Voyager, you send your message and then you go home and you wait two days before you finally get a response,” Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory, said in a mission update.
Voyager 1 is traveling at approximately 38,000 mph (61,000 kilometers per hour) relative to the Sun. Despite that speed, it has taken nearly five decades to reach its current distance.
The spacecraft entered interstellar space in August 2012 after crossing the heliopause, the boundary separating the region dominated by the solar wind from the surrounding interstellar environment.
Voyager 1 continues collecting scientific information beyond that boundary, including measurements of galactic cosmic rays and conditions in the space between stars.
Its twin spacecraft, Voyager 2, entered interstellar space in November 2018 after completing encounters with Jupiter, Saturn, Uranus and Neptune. Voyager 2 remains closer to Earth and is expected to reach the one-light-day distance in November 2035.
Both spacecraft were originally launched to explore the outer solar system, taking advantage of a planetary alignment that allowed them to use gravitational assistance to travel between planets.
Voyager 1 photographed Jupiter and its moons in 1979 before reaching Saturn in 1980. Its observations revealed previously unknown details about the planets’ rings, atmospheres and natural satellites.
Among its discoveries were a thin ring around Jupiter and two Jovian moons, Thebe and Metis. At Saturn, the spacecraft identified additional moons and a previously unknown ring.
In 1990, Voyager 1 captured the photograph known as the “Pale Blue Dot,” showing Earth as a tiny point of light from approximately 3.7 billion miles away. The image became part of a final collection of solar system photographs before the spacecraft’s cameras were permanently switched off to conserve power.
The probe continues functioning despite aging equipment and declining electricity supplies from its radioisotope thermoelectric generators, which produce power using heat released by the radioactive decay of plutonium-238.
NASA engineers have gradually shut down instruments and other equipment to conserve electricity and extend the mission’s operating life.
The spacecraft has also experienced communications difficulties. In a November mission update, NASA reported that engineers had resolved a temporary communications interruption while continuing efforts to manage the spacecraft’s limited power supply.
Because of its extreme distance, controllers must plan operations around lengthy communication delays. Engineers use NASA’s Deep Space Network, a system of large radio antennas located in California, Spain and Australia, to exchange commands and scientific data with the spacecraft.
Voyager 1 and Voyager 2 also carry Golden Records containing images, natural sounds, music and greetings in 55 languages. The records were designed to represent life and culture on Earth to any civilization that might encounter the spacecraft in the distant future.
NASA plans to recognize the upcoming milestone with public events on Nov. 17 and 19.
The agency is inviting people around the world to participate in its “Shine Bright for Voyager’s Light-Day” celebration after sunset Tuesday, Nov. 17. Participants are encouraged to use flashlights, mobile phones and other lights to transmit the Voyager mission’s call sign, VGR, in Morse code.
NASA will also host a moderated discussion Nov. 19 featuring members of the Voyager mission team.
According to the agency’s Nov. 10 announcement, the events will recognize both the distance Voyager 1 has traveled and the continued operation of a spacecraft launched almost half a century ago.
Reaching one light-day will not produce any physical change aboard Voyager 1 or alter the surrounding environment. The milestone instead marks the spacecraft’s growing separation from Earth as it continues traveling through interstellar space.
NASA expects Voyager 1 to reach the distance early Wednesday morning, establishing another record for the longest-operating mission to explore beyond the outer planets.
Original article
Comments