Large-scale array for radio astronomy on the farside (LARAF)

Abstract

At the Royal Society meeting in 2023, we have mainly presented our lunar orbit array concept called DSL, and also briefly introduced a concept of a lunar surface array, LARAF. As the DSL concept had been presented before, in this article, we introduce the LARAF. We propose to build an array in the far side of the Moon, with a master station which handles the data collection and processing, and 20 stations with maximum baseline of 10 km. Each station consists of 12 membrane antenna units, and the stations are connected to the master station by power line and optical fibre. The array will make interferometric observation in the 0.1–50 MHz band during the lunar night, powered by regenerated fuel cells. The whole array can be carried to the lunar surface with a heavy rocket mission, and deployed with a rover in eight months. Such an array would be an important step in the long-term development of lunar-based ultralong wavelength radio astronomy. It has a sufficiently high sensitivity to observe many radio sources in the sky, though still short of the dark age fluctuations. We discuss the possible options in the power supply, data communication, deployment etc. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.

Astronomy from the Moon: the next decades (part 2)

“…The lunar low-frequency radio story began in 2019 with the Chinese National Space Agency Chang'e 4 antenna, the first payload to land on the far side but which suffered from radio interference from the lander. Xuelei Chen [ 4 ] (of the National Astronomical Observatory of China) described the current preparation by China to launch its Discovering the Sky at the Longest Wavelengths programme, a flotilla of nine radio satellites with dipole antennae for interferometery, along with a mother satellite for data transmission, flying in formation in selenocentric orbit, along with a mother ship where the data will be transmitted to Earth every two hours. Launch is projected for 2026.…”