330 million light-years across and almost entirely empty, the Boötes Void is one of the largest known holes in the universe. An area its size should hold roughly 2,000 galaxies — it contains around 60. Astronomers found it by accident in 1981, and it still forces uncomfortable questions about dark energy and how the cosmic web took shape.
The reference file on the 'Great Nothing' — its 1981 discovery by Robert Kirshner, its staggering emptiness, and the soap-bubble theory of how smaller voids merged to make it.
A clear, gripping tour of the void: how big it really is, the famous line that if the Milky Way were in it we wouldn't have known other galaxies existed until the 1960s.
BBC Sky at Night on how a routine redshift survey stumbled onto a region of nothingness — and why the cosmic web is mostly empty space strung between filaments.
Astrophysicist Becky Smethurst on how light passing through supervoids gets subtly cooled, giving us one of the cleanest fingerprints of dark energy at work.
Why voids like Boötes are prized laboratories for testing cosmology — and how to find the patch of sky where this abyss actually lives.
Science Focus unpacks the physics of voids: gravity slowly drains matter out of underdense regions, deepening the emptiness over billions of years.
A short, university-made explainer that puts the void in the context of the largest-scale structure of the universe.
A readable primer on what it would mean to sit inside the void — where the nearest galaxies are so far away the sky would look almost perfectly black.