Editor's Summary
18 January 2007
The unseen universe
The cover shows part of the first map of the large-scale distribution of 'dark matter' in the Universe, constructed using images obtained in the largest ever survey with the Hubble Space Telescope. Dark matter is a mysterious substance that dominates the mass of the Universe, but neither emits nor reflects light, so is consequently invisible. It can be detected indirectly via gravitational lensing, the deflection of light from distant galaxies by any foreground concentrations of mass. The new map depicts a network of dark matter filaments that have grown over time and are separated by huge voids. Ordinary 'baryonic' particles (which account for only a sixth of the total mass in the Universe) subsequently build all stars, galaxies and planets inside this underlying scaffold of dark matter, during a process of gravitationally induced structure formation. (Cover image: NASA/ESA/R. Massey.)
News and Views: Cosmology: The Universe's skeleton sketched
The deepest and clearest maps yet of the Universe's skeleton of dark-matter structure present a picture broadly in concord with favoured models — although puzzling discrepancies remain.
Eric V. Linder
doi:10.1038/nature05522
Letter: Dark matter maps reveal cosmic scaffolding
Richard Massey, Jason Rhodes, Richard Ellis, Nick Scoville, Alexie Leauthaud, Alexis Finoguenov, Peter Capak, David Bacon, Hervé Aussel, Jean-Paul Kneib, Anton Koekemoer, Henry McCracken, Bahram Mobasher, Sandrine Pires, Alexandre Refregier, Shunji Sasaki, Jean-Luc Starck, Yoshi Taniguchi, Andy Taylor and James Taylor
doi:10.1038/nature05497
First paragraph | Full Text | PDF (1,163K) | Supplementary information
