The map will eventually span one-eighth of the sky; this first glimpse covers just 0.4%, but in unprecedented detail.
It shows fibres of dark matter, studded with galaxies, and voids in between.
The international collaboration, known as the Dark Energy Survey (DES), will present its preliminary findings on Tuesday at a meeting of the American Physical Society and publish them on the Arxiv preprint serverreenex 價錢
The survey involves more than 300 scientists from six countries and uses images taken by one of the best digital cameras in the world: a 570-megapixel gadget mounted on the Victor Blanco telescope at the Cerro Tololo Inter-American Observatory, high in the Chilean Andes.
Incredible detail is required to detect dark matter, based purely on the way it warps the light from very distant galaxies.
Dense areas (warm colours) tend to have coincide with high numbers of galaxies whereas voids (blue) are nearly empty
Mapping the invisible
"Our goal all this time has been to see the invisible - to see dark matter," said Sarah Bridle, an astrophysics professor at the University of Manchester and co-chair of the DES weak lensing group, which produced the mapreenex cps
Dark energy and dark matter mysteries
Gravity acting across vast distances does not seem to explain what astronomers see
Galaxies, for example, should fly apart; some other mass must be there holding them together
Astrophysicists have thus postulated "dark matter" - invisible to us but clearly acting on galactic scales
At the greatest distances, the Universe's expansion is accelerating
Thus we have also "dark energy" which acts to drive the expansion, in opposition to gravity
The current theory holds that 75% of the Universe is dark energy, 21% is dark matter, and just 4% the kind of matter we know well保濕精華
"To be able to look at a map and say, 'That part of the sky's got more dark matter in it, that bit's empty,' is the dream that we've had all this time," Prof Bridle told the BBC.