Mitaka
Japanese

4D2U Project
NAOJ

Tutorial

Let's explore the universe as revealed to us by the latest discoveries in astronomy!

This tutorial will show you how to install the software and how to use it visit various objects in the universe.
For details, please read the manual (mitaka_manual.pdf).

Install

Decompress the .zip file in any folder.

Launch

Double click mitaka.exe and wait until all the astronomical data are loaded.

Planetarium Mode

In planetarium mode, Mitaka shows the sky as seen from a particular location on a planet. When Mitaka stars up, it shows the night sky in Mitaka, Tokyo, at 8PM.

The night sky is displayed.

Push the left mouse button while dragging your mouse across the sky to change the direction you're seeing. Push the right mouse button while dragging your mouse, or use your mouse wheel, to change the viewing angle.

Changing the Time

Bring the cursor to the upper-right corner of the Mitaka window. Buttons labeled "+" and "-" will appear.

Buttons for time handling.
Move the viewing time forward by clicking "+" and backward by clicking "-".
These buttons will disappear if you move the cursor away from the upper-right corner.

The time increment is initially set to 10 minutes. If you click either "+" or "-" with the right mouse button, a menu will appear that will allow you to change the time increments from 10 seconds to 100 years.

Pop-up menu for time handling.
You can also set the time directly by selecting `Set Time...' in this menu.

Space Mode

Take off from Earth and begin exploring outer space by selecting "Landing/Take Off" from the menu bar or by pressing the mouse wheel.

Once you take off, you are floating in space several kilometers above Mitaka facing the same direction as you were in planetarium mode.

Just after takeoff

Zoom out by dragging the mouse with the right button down or by using the mouse wheel. Another method is to bring the cursor to the lower-right corner of the window until "+" and "-" buttons appear. Holding the left mouse button down on "+" zooms out, on "-" zooms in.

Zoom in and zoom out buttons

Keep zooming out until you can see the whole Earth against a background of stars. If the clock is set to night-time, you will see the side of Earth that is in shadow.

Earth's night side
You can bring different parts of Earth into view by dragging the mouse with the left button down. Double clicking on any point on Earth will move it to the center.
Let's move to the day side of the Earth.
Earth's day side
Zoom back towards Earth using the "-" button until a green "+" sign appears on the surface.
The green pointer indicating location on the surface. Approaching the ground.
You can land there by selecting "Landing/Take Off" from the menu bar or pushing the mouse wheel.
If you land on Earth's day side, you will see a blue sky.
Forward the time to night, you can see the starry sky at that location.

To continue with the tutorial, take off and zoom out again so you can see the whole Earth.
If you advance the time forward, you can see that Earth rotates once every 24 hours.

Exploring the Solar System

To leave Earth and explore the solar system, continue to zoom out. Earth becomes smaller and smaller. For awhile, you will only see stars in the background.
Distances between the planets are much larger than the size of the planets.
Eventually you will begin to see other objects in our solar system: planets and asteroids.

The inner solar system
The blue lines show the orbits of the planets. Red circles indicate distances from the Sun. We call these "Scale Circles". These help us understand the size of the structures we are looking at.

The units we use for scale are:

UnitExplanation
Astronomical Unit (AU) The mean distance between Earth and Sun.
1 AU is equal to approximately 150 million kilometers.
Light Year (l.y.) The distance light travels in a year.
1 l.y. is equal to approximately 9.5 trillion kilometers, or 63 thousand AU.

Earth is now the "target object" and is at the center of the view. Other planets can be placed at the center of the view by selecting them in the "Target" menu.
Let's choose Mars as our next target by selecting "Target"-"Solar System"-"Mars" and go there by selecting "Target"-"Move to the target".

Now Mars is fixed at the center of the view and you can zoom in and out and land and take off from Mars just as we did from Earth.

Mars

You can explore other planets such as Jupiter and Saturn in the same way.

Jupiter Saturn

To explore the outer reaches of the solar system, keep zooming out from any planet.

Orbits of Jupiter and Saturn
The planets are small compared to the size of the solar system, so all you can see will be their orbits and names. You can exaggerate the size of the planets by selecting from the "View" menu "View"-"Planet/Moon"-"Magnification Rate".

Traveling to the Limits of the Observable Universe

Now it is time to go to the edges of the known universe.
Keep zooming out farther and farther. You will pass all the planets and the Oort cloud, the hypothesized home of long period comets.
You are now in the realm of the stars.
Notice that the scale lines are now labeled in light years in stead of astronomical units.

The Oort cloud and nearby stars

Names of familiar stars will zoom by.

Stars in the solar neighborhood
Distances to nearby stars were determined by the Hipparcos satellite. The Mitaka program only shows stars with accurate distance measurements, generally within 3000 light years of the Sun.

Once we leave the solar neighborhood, our galaxy, the Milky Way, comes into view.

A model of what our galaxy would look like from the outside

The Milky Way is a barred spiral galaxy with about 200 billion stars.
The Solar System is quite far from the center of the Milky Way.

Continue zooming out, and the Milky Way turns into a point among many other points.
You have entered the realm of the galaxies.
Each point is no longer a star but a galaxy containing billions of stars.

The distribution of galaxies near our Galaxy

Beyond 1 billion light years from Earth, we see the distribution of galaxies observed by the Sloan Digital Sky Survey (SDSS).
Astronomers have only been able to observe the universe in fan-shaped wedges, but even the uncharted parts of the universe must be full of galaxies.

The large scale structure of the universe
If you look closely, the distribution of galaxies has denser and sparser regions. These variations are the large scale structure of the universe.

Finally, you will arrive at a distance of 13.7 billion light years from Earth.
This is the edge of the observable universe. The universe has not existed long enough for information from beyond 13.7 billion light years to reach us.

The edge of the observable universe

Now you can return to Mitaka, Tokyo.
You can either zoom your way back, or select "Landing/Take Off"-"Landing on Mitaka" from the menu to return in an instant.

Mouse Operations

Drag with left button downChange the view direction.
Drag with right button down, or wheelingZoom in/out (space mode). Change the viewing angle (planetarium mode).
Double click (left button)Move to the double-clicked point on a planet's surface.
Click + button in the upper-right cornerMove time forward.
Click - button on the upper-right cornerMove time backward.
Right-click in the upper-right cornerOpen pop-up menu for time handling.
Click + button in the lower-right cornerZoom out.
Click - button in the lower-right cornerZoom in.
Right-click in the lower-right cornerOpen pop-up menu for scale selection.
Push the wheel buttonLand or take off a planet.

Keyboard Operations

ArrowChange the view direction.
1 + ArrowSlue the view (only for the space mode).
Page UpZoom in.
Page DownZoom out.
4Move time forward
3Move time backward
Z + 4Increase the time step (up to 100 years).
Z + 3Increase the time step (down to 10 seconds).
SLand or take off from a planet.
XOpen a menu on screen. (X and Z navigate the menu).
AShow or hide labels.
FShow or hide frame rate per second.

Enough for today! Have a nice evening!

You have now mastered the basic features of Mitaka.
If you want to explore other features read the PDF manual and have fun!