Lost and re-found: Soviet Lunokhod-1
- Transfer
In November 1970, the Soviet station sank to the surface of the moon. The all-terrain vehicle, called the "Lunokhod-1", descended to the surface for experiments and taking photographs. On board the all-terrain vehicle was a French-made reflector that scientists on Earth could use to calculate distances and a better understanding of lunar geology.
Ten months later, Lunokhod-1 fell silent, and its whereabouts on the moon became unknown. Over the years, scientists sometimes sent a laser signal around its last known coordinates, hoping for the return of the beam from the reflector. But there was no answer, and they decided that the all-terrain vehicle fell into the crater or drove under a rock, which prevents the signal from Earth.
But the situation changed last weekend, when scientists armed with high-resolution photographs obtained from NASA's lunar reconnaissance orbital module, marked the coordinates of Lunokhod-1.
“It turned out that the difference in distance from the previous supposed location of the all-terrain vehicle to the real one was kilometers,” says Tom Murphy, University of California, San Diego. Using a 3.5-meter telescope at Apache Point Observatory, New Mexico, Murphy and his team sent laser pulses to the coordinates of the newly found Lunokhod-1 and found a retroreflector in excellent condition.
“We did not expect to see it so bright - at least five times brighter than another Soviet reflector, on Lunokhod-2, to which we regularly send laser pulses,” Murphy said in a press release from the discovery.
The distance between the Lunokhod-1 reflector and the Earth was calculated with an accuracy of 1 cm (0.4 in.). The second dimension, 30 minutes later, allowed scientists to triangulate the position of the reflector on the moon with an accuracy of 10 meters (32.8 feet). Further clarification of the location is expected in the coming months.
Scientists want to add Lunokhod-1 location data to other information in an existing network. In addition to Soviet reflectors, NASA astronauts placed a laser reflector on the lunar surface during the Apollo 1969-1972 mission on the moon. This information is used to collect an idea of the core of the moon and its gravitational field. Scientists also expect to use the data to learn more about moon dust, which appears to obscure the return of the laser beam in the future.
“During the full moon, the amount of light returned decreases by a factor of ten,” Murphy said. “We need to understand what is the reason for this if we plan to send additional scientific equipment to the moon.
Ten months later, Lunokhod-1 fell silent, and its whereabouts on the moon became unknown. Over the years, scientists sometimes sent a laser signal around its last known coordinates, hoping for the return of the beam from the reflector. But there was no answer, and they decided that the all-terrain vehicle fell into the crater or drove under a rock, which prevents the signal from Earth.
But the situation changed last weekend, when scientists armed with high-resolution photographs obtained from NASA's lunar reconnaissance orbital module, marked the coordinates of Lunokhod-1.
“It turned out that the difference in distance from the previous supposed location of the all-terrain vehicle to the real one was kilometers,” says Tom Murphy, University of California, San Diego. Using a 3.5-meter telescope at Apache Point Observatory, New Mexico, Murphy and his team sent laser pulses to the coordinates of the newly found Lunokhod-1 and found a retroreflector in excellent condition.
“We did not expect to see it so bright - at least five times brighter than another Soviet reflector, on Lunokhod-2, to which we regularly send laser pulses,” Murphy said in a press release from the discovery.
The distance between the Lunokhod-1 reflector and the Earth was calculated with an accuracy of 1 cm (0.4 in.). The second dimension, 30 minutes later, allowed scientists to triangulate the position of the reflector on the moon with an accuracy of 10 meters (32.8 feet). Further clarification of the location is expected in the coming months.
Scientists want to add Lunokhod-1 location data to other information in an existing network. In addition to Soviet reflectors, NASA astronauts placed a laser reflector on the lunar surface during the Apollo 1969-1972 mission on the moon. This information is used to collect an idea of the core of the moon and its gravitational field. Scientists also expect to use the data to learn more about moon dust, which appears to obscure the return of the laser beam in the future.
“During the full moon, the amount of light returned decreases by a factor of ten,” Murphy said. “We need to understand what is the reason for this if we plan to send additional scientific equipment to the moon.