Abstract
Abstract A new era of exploration of the low radio frequency universe from the Moon will soon be underway with landed payload missions facilitated by NASA's Commercial Lunar Payload Services (CLPS) program. CLPS landers are scheduled to deliver two radio science experiments, Radio wave Observations at the Lunar Surface of the photoElectron Sheath (ROLSES) to the nearside and Lunar Surface Electromagnetics Experiment (LuSEE) to the farside, beginning in 2021. These instruments will be pathfinders for a 10 km diameter interferometric array, Farside Array for Radio Science Investigations of the Dark ages and Exoplanets (FARSIDE), composed of 128 pairs of dipole antennas proposed to be delivered to the lunar surface later in the decade. ROLSES and LuSEE, operating at frequencies from ≈100 kHz to a few tens of megahertz, will investigate the plasma environment above the lunar surface and measure the fidelity of radio spectra on the surface. Both use electrically short, spiral-tube deployable antennas and radio spectrometers based upon previous flight models. ROLSES will measure the photoelectron sheath density to better understand the charging of the lunar surface via photoionization and impacts from the solar wind, charged dust, and current anthropogenic radio frequency interference. LuSEE will measure the local magnetic field and exo-ionospheric density, interplanetary radio bursts, Jovian and terrestrial natural radio emission, and the galactic synchrotron spectrum. FARSIDE, and its precursor risk-reduction six antenna-node array PRIME, would be the first radio interferometers on the Moon. FARSIDE would break new ground by imaging radio emission from coronal mass ejections (CME) beyond 2R ⊙, monitor auroral radiation from the B-fields of Uranus and Neptune (not observed since Voyager), and detect radio emission from stellar CMEs and the magnetic fields of nearby potentially habitable exoplanets.
Highlights
Even before Apollo 11ʼs first human landing on the Moon, low radio frequency telescopes were being proposed for the lunar surface
At the first Lunar International Laboratory Symposium held in Athens in 1965, a Lunar Radio Astronomy Observatory was described that would eliminate restrictions on observations at ∼kilometer wavelengths (∼0.3 MHz) from the ground due to ionospheric and human-produced radio frequency interference (RFI; Gorgolewski 1966)
Appropriate thermal noise was added to create a more realistic response of FARSIDE to the model Type II emission. These data were imaged and “cleaned” using the widefield imaging software WSClean (Offringa et al 2014), with the resulting image shown in panel (D) of Figure 11. This simulation pipeline confirms that FARSIDE would provide unprecedented imaging capabilities for LF solar radio bursts, and could help explain how energetic particles are being accelerated at coronal mass ejections (CME)-driven shocks
Summary
Even before Apollo 11ʼs first human landing on the Moon, low radio frequency telescopes were being proposed for the lunar surface. Renewed interest in the Moon beginning in 1984 with the conference on Lunar Bases and Space Activities of the 21st Century brought forth new ideas for a lunar low-frequency (LF) radio array (Douglas & Smith 1985) and a Moon–Earth baseline radio interferometer (Burns 1985) This was followed by additional low radio frequency mission concepts in workshops on Future Astronomical Observatories on the Moon (Burns & Mendell 1988), Low Frequency Astrophysics from Space (Kassim & Weiler 1990), Science Associated with the Lunar Exploration Architecture (NASA Advisory Council 2007), and more recently, Discovering the Sky at the Longest Wavelengths with Small Satellite Constellations (Chen et al 2019).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
