Recommended Free Tools
Uchuu is a dark-matter simulation whose researchers generated about 3 petabytes (3,000 terabytes) of data—not a 3,000-TB file that everyone can simply download. A 2021 release said compressed data products were made available as a 100-terabyte catalog through cloud infrastructure. The sources establish that the data was released then, but do not confirm that the catalog or its original access instructions remain available today.
What Uchuu simulates
Uchuu is a cosmological N-body simulation: it models how dark matter and large-scale cosmic structure evolve under gravity. Its largest run contains 2.1 trillion dark-matter particles in a cube 2.0 gigaparsecs per side, measured in the paper’s convention of Gpc/h. The Center for Computational Astrophysics’ 2021 release describes that scale as 9.63 billion light-years per side.
The simulation follows matter’s evolution over nearly 13.8 billion years, from the Big Bang to the present, according to that institutional release. It is not a detailed digital copy of every visible object: individual stars and planets are not resolved. Instead, the simulation is useful for studying dark-matter halos and the large-scale structure in which galaxies form.
Why the headline says 3,000 TB
The 3-petabyte figure refers to data generated by the project, not the size of a single download offered to the public. Tomoaki Ishiyama, the simulation’s code developer, said the work consumed 20 million supercomputer hours and generated 3 petabytes. The institutional release said the compressed information was made into a 100-terabyte catalog. Those numbers describe different stages and should not be treated as interchangeable: 100 TB is still a very large dataset, but it is not 3,000 TB.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problems#1 Best Overall
What data products were released
The 2021 Data Release 1 paper describes publicly available products including:
- Subsets of simulation particles
- Matter power spectra, which describe the distribution of matter across spatial scales
- Halo and subhalo catalogs, listing structures identified in the simulation
- Merger trees, which trace how structures assemble over time
The paper described gravitational-lensing maps and mock catalogs for galaxies, X-ray clusters, and active galactic nuclei as future releases at the time it was published. That wording reflects the 2021 paper; it does not establish their current release status.
Can you download Uchuu now?
The Center for Computational Astrophysics said in 2021 that the compressed catalog was available through cloud infrastructure and pointed readers to the Skies & Universes Uchuu page. The cited sources confirm historical release and access, but do not verify present-day availability, account requirements, file formats, or a working download procedure. Check the project page and its linked access information for current instructions rather than assuming the 2021 route still works.
Do not plan on downloading 3 PB as though it were one ordinary file. Even the reported 100-terabyte catalog would require substantial bandwidth and specialized storage for a complete local copy. The sources do not say that local storage is required; researchers may be able to work with selected products or subsets, depending on the access options currently offered.
Rank #3
What Uchuu is useful for
Uchuu lets researchers examine simulated cosmic structure at different scales and times. A user can study catalogs of dark-matter halos, follow how structures merge, or compare matter distribution across scales. It is a research dataset, not a consumer app or a visualization that automatically contains resolved planets, stars, or every galaxy in detail. Julia F. Ereza, a doctoral researcher at IAA-CSIC who uses Uchuu to study large-scale structure, described its value as being able to move through time and examine the universe at different scales.
Quick Recap
Sources and dates
- Ishiyama et al., “The Uchuu simulations: Data Release 1 and dark matter halo catalogs,” 2021, for simulation scale and released data products.
- Center for Computational Astrophysics, 2021 institutional release, for the 9.63-billion-light-year scale, simulated timeline, computational effort, generated data volume, compressed catalog, and historical cloud access statement.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
