A space-based radio telescope will open an unexplored window below 45 MHz.

Earth's atmosphere blocks very low radio frequencies, so astronomers cannot study this part of space from the ground. This blocks answers to major questions across astrophysics, cosmology, and planetary science. To fix this, researchers propose the MegaWave Radio Surveyor. It is a concept for an observatory made of multiple spacecraft in space working together as an interferometer. An interferometer combines signals from spaced-out instruments to act like one giant telescope. Operating below 45 MHz, it would deliver unprecedented angular resolution and sensitive observations. This design lets scientists track the space weather of distant stars and detect magnetic radio signals from exoplanets to check their interiors and atmospheres. It would also study the early Universe during the Dark Ages using the highly-redshifted HI hyperfine line and assess how cosmic rays and magnetic fields shape the cosmic web. Recent commercial space developments now make building this space mission possible.

Why it matters

This observatory would let us study exoplanet magnetic fields, which protect atmospheres and could indicate habitability. It would also probe the universe's Dark Ages, a period we know almost nothing about. By opening a new radio window, it could answer fundamental questions about stars, planets, and cosmic structure.

Questions answered