4D2U Navigator


About the 4D2U Project

The universe encompasses all of space and time.

The most immense cosmic structures - galaxies gathered into clusters and superclusters - dominate the universe everywhere we look. Astronomers constantly work to understand these structures bit by bit. The Four-Dimensional Digital Universe project is an outgrowth of their search for cosmic understanding.

The project's goal is to visualize astronomical data in a way that helps watchers feel as if they are witnessing the unfolding of the universe. "Four dimensions" refer to the three dimensions of space and the one dimension of time embedded in their data. "Digital" refers to computer graphics visualizations of digital data. The resulting acronym is "4D2U", and it is also astronomy's way of saying "4D to you."

The 4D2U project is created by and for astronomers, but it is really a gift to the world.

For astronomers, the goal is to provide a rare 3D view of data to help with research. Unrestricted explorations in 3D are essential tools for understanding modern observational data and computer simulations.

For everyone else, the goal is to present the latest research results in a way that is scientifically accurate, but also fun and easy to understand.

To reach these goals, we have been developing 4D visualization platforms and content in the form of an experimental 4D visualization theater and a library of data visualizations. The data include observations and theoretical models of astronomical objects, and computer simulations of astronomical phenomena. Since the project began in 2001, we have established the fundamental techniques for visualizing these different types of data.

The 4D2U is a long-term project by the National Astronomical Observatory of Japan. We plan to continue improvements in our visualization data library and further development of new visualization platforms, including domed and portable theaters.

We hope you'll have the opportunity to experience 4D2U. The project hosts public showings every two months at the NAOJ headquarters in Mitaka, Japan. The Imiloa Astronomy Center in Hilo, Hawai'i, shows a short 4D2U movie each day.

Project Introduction Pamphlet


A4 format PDF (16MB) (Note: This is a low resolution version for web distribution.)


In order to use the 4D2U contents, you are required to agree to the Terms and Conditions of Use. >> Please read.

Mitaka : The Four-Dimensional Universe Viewer


Mitaka is software for visualizing the known Universe with up-to-date observational data and theoretical models. Mitaka users can seamlessly navigate through space, from the Earth to the edges of the known Universe. The software is available through a free download from here.

System Requirements

OS : Windows 10/8.1/8/7/Vista/XP
CPU : Pentium4 1.8GHz or better
RAM : 512MB or more
Hard Disk Space : 150MB or more
Graphics Adapter : GeForce 3 or better
Display Resolution : 1024x768 pixels (XGA) or more

Movie Contents

The 4D2U Project produces movies visualizing observational and computational data. These movies are downloadable.

Dark Mattar Halo 2.
This video focuses on the formation and evolution of the dark matter distribution from the early Universe to the present.
>> Details and Download
Formation of the Moon
This video shows how the Moon fromed from a proto-lunar disk created by a collision between the the proto-Earth and another protoplanet.
>> Details and Download
Formation of a Spiral Galaxy
This video focuses on the formation and evolution of a spiral galaxy.
>> Details and Download
Dynamics of Saturn's Ring (I. Wake Structure)
This video shows the motion of ice particles in the Saturn's rings.
>> Details and Download
Electromagnetic Radiation from Neutron Star Mergers
This video shows the results of numerical simulations for a neutron star merger.
>> Details and Download
Dynamics of Saturn's Ring (II. Propeller Structure)
This video introduces a computer simulation of the formation process of a propeller structure in Saturn's Ring.
>> Details and Download
Giant Impact of Protoplanets
This video shows a typical giant impact between two Mars-sized protoplanets, which likely happened early in the giant impact stage.
>> Details and Download
Formation of Planetesimals
This video introduces numerical simulations of planetesimal formation based on gravitational instability.
>> Details and Download
A Journey Through the Milky Way
This movie displays the various structures of the simulated Milky Way Galaxy, based on fundamental physical processes such as the gravitational interactions between stars and gas; the dynamics and evolution of the gas; star formation from the gas clouds; and energetic feedback from the stars.
>> Details and Download
Collisional Growth of Dust
This movie shows collisional growth process of dust grains in protoplanetary disks.
>> Details and Download
Chariklo's Double Rings
In this simulation, for the first time an entire ring structure was calculated using realistic partical sizes. Chariklo's rings revealed by the numerical simulation is like waves in a river.
>> Details and Download
Thermal Convection and Magnetic Fields in the Solar Interior
Let's watch this movie of the solar interior based on computer simulations calculating the flows and the magnetic fields in the solar interior.
>> Details and Download
Formation of a Multiple-Star System
In this simulation, we follow the formation process of multiple-star systems on various spatial scales.
>> Details and Download
Asteroid Collisions and Shape Evolution
This video depicts the collisional destruction of asteroids and the formation of rubble-pile bodies.
>> Details and Download
Gas Disk around a Black Hole
This movie shows how the gas glows brightly as it falls towards the black hole, based on recent numerical simulations.
>> Details and Download
Formation and Evolution of Dark Matter Halos (III. Formation of Cosmic Web and Void Structures)
This movie visualizes the evolution of dark matter distribution in one of a series of simulations, named Uchuu.
>> Details and Download

In order to use the 4D2U contents, you are required to agree to the Terms and Conditions of Use. >> Please read.

Zindaiji : An Astronomical Many-Body Simulation Visualizer


Zindaiji is Windows PC software for visualizing astronomical many-body simulation data. Zindaiji helps researchers visualize large many-body simulations with an intuitive GUI. It also creates high quality movies suitable for theater presentations. It's available from here.

4D2U Navigator English Version


4D2U Navigator English Version (<- click to launch)
The 4D2U Navigator is a Flash-based interactive astronomical content viewer. By using this viewer, you can seamlessly fly through the hierarchical structure of the universe, and watch astronomical simulation movies such as 'The Origin of the Moon' or 'Formation of a Spiral Galaxy' made by the project.
To use the 4D2U navigator you need to install Flash Player (version 8 or above) on your computer. If it's not already installed, you can download the software for free from the Adobe website.

Copyright and Usage Notice

Terms and Conditions of Use

In order to use the 4D2U contents, you are required to agree to the following Terms and Conditions of Use. You may use the contents only after you review and agree to these Terms and Conditions of Use.

Use of Copyrighted Material on this Website

For personal use and educational use at schools

Anyone can use the 4D2U contents for personal or non-commercial educational purposes without needing apply for permission. Explicit credit shall be given to the 4D2U Project, such as "Courtesy of the 4D2U Project, NAOJ."

Showings at museums and planetariums, and use in movies and published materials

Partyies wishing to use the 4D2U contents for these purposes shall send application form for request permission by e-mail prior to showing the contents or reproducing the materials. The application forms can be downloaded from these icons,

Application form for 4D2U contents

Please fill the form and send it to 4d2u-apply _at_ nao.ac.jp (please change "_at_" to "@").


You may use e-mail for giving us feedback on the use of our website or its content. We apologize in advance that we will be unable to respond to individual comments.
E-mail adress is 4d2u-web _at_ cfca.nao.ac.jp (please change "_at_" to "@").


Update History

  • 2015/09/27 English version of 4D2U Website was updated.
  • 2007/07/1 English version of 4D2U Navigator opened.
  • 2006/07/21 English version of 4D2U Website opened.