Five years after the collapse of the Arecibo Telescope, a radio telescope is back online. The signal is back.
This article details a DIY hydrogen-line radio telescope built from affordable materials like foam insulation board, a paint thinner can, an SDR (AirSpy), and amplifiers. It explains how to detect the 1420.4-MHz signal emitted by hydrogen to image the galaxy and measure galactic rotation.
Wi-Fi was developed by a team of scientists including John O'Sullivan, who worked at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia. The technology emerged from research into radioastronomy that aimed to detect the echoes of the Big Bang.
