The Long Wavelength Array (LWA) is a radio telescope in central New Mexico. It began preliminary tests of the hardware in 2011, and began regular operations in late 2015. It is one of the few observatories to utilize relatively low frequencies (10-88 MHz), and is used to study relativistic particles, cosmic evolution, astrophysical plasma, decametric radio emissions from Jupiter-like extrasolar planets, and giant flares from magnetars.

As of 2011 it consisted of a single station with 256 antennas. The longer term objective of the project is to build 53 stations in total, with a total of 13,000 dipole antennas strategically placed in an area nearly 400 kilometres (250 miles) in diameter, to scan the sky at HF and VHF frequencies. Each antenna stands about 1.5 metres (5 ft) high and about 2.7 metres (9 ft) across the base. The first station, located adjacent to the NRAO's VLA, consists of 256 antennas and was completed in December 2009. It was dedicated in April 2010, and routine operations began in 2011. The second station (LWA2) was under construction about 19 km (12 mi) away as of 2011.

The project is a collaboration of UNM, VT, LANL, JPL, NRL, UI, BIRS, NRAO and AFRL.

• Australian Square Kilometre Array Pathfinder
• List of astronomical observatories
• LOFAR
• MeerKAT
• Murchison Widefield Array
• Square Kilometre Array