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Astronomy & Space Simulator

Travel through an interactive solar system, compare planets, follow the Moon’s phases, and discover just how vast space really is.

✦8 planets1 stellar neighborhood

J2000 ecliptic projection

Planet symbols enlarged · not to scale

Compressed distance

Date (UTC)Speed

Orbits LabelsScale

ACCESSIBLE ORBIT DATA

Positions at the selected date

Heliocentric ecliptic coordinates, approximate radial distance and speed. Distances use AU; longitudes and latitudes use degrees.

Planet	Sun distance (AU)	Longitude (°)	Latitude (°)	Speed (km/s)

About this model: Approximate heliocentric orbits using JPL elements (1800–2050). Earth represents the Earth–Moon barycenter. Orbital paths are projected onto one plane; positions are not high-precision ephemerides. Planet markers are exaggerated for visibility.

DISTANCE & SCALE

Space is mostly… space.

Measure distances between worlds at the selected simulator date, or explore their average distances from the Sun.

FromTo

APPROXIMATE SEPARATION

✳

One-way light travel time at the selected date

Distances are between modeled 3D heliocentric positions, not fixed orbital radii. Actual light-time calculations require more precise ephemerides.

DISTANCE RULER

Average Sun distance (AU)

linear

1 AU = 149.6 million km. Bars show mean semimajor axis, not the changing distance between planets.

BUILD THE SOLAR SYSTEM

What if the Sun were a small ball?

Set the Sun’s model diameter to see how tiny the planets would be and how far away their mean orbits would sit. Sizes and distances in this table share one true scale.

Sun diameter10 cm

Planet	Planet diameter (mm)	Orbit radius (m)

Mean orbit radius is the semimajor axis; planetary positions and actual separations change over time.

Why do the outer planets look crowded in the orbit view?

Compressed distance uses a square-root transform to fit all eight planets. Switch to linear in the Solar System tab to see why the inner planets disappear near the Sun.

Why aren’t the planet sizes drawn accurately?

Planet diameters span almost 30×, while orbit sizes span nearly 80× from Mercury to Neptune. One single view cannot keep both realistic and readable.

Using Astronomy & Space Simulator

Choose a supported date in the orbital explorer, select a planet and inspect its modeled position. Compare planet sizes, use the shared-scale table and explore idealized Moon phases. Export the data table or a supported view snapshot.

The JPL approximate orbital fit is limited to 1800-2050, with dates evaluated at 12:00 UTC and Earth represented by an Earth-Moon barycenter proxy. The view projects orbits onto the ecliptic plane and exaggerates planet markers. Moon phases use a constant synodic month; these are educational models, not observational predictions or spacecraft guidance.

Choose modeled orbit data, scale comparisons or a snapshot

Orbital explorer: inspect approximate modeled positions within the supported date range.

Comparison tables: review the supplied modeled/scale information with its stated assumptions.

CSV: export supported planet-position data for reference.

SVG or PNG: share a supported view, not an observational image.

Practice: compare model dates

Choose a supported date and select one planet.

Inspect its modeled position, then change the date while keeping the selected object fixed.

Export a table or snapshot with the model date and limitations clearly identified.

This is an authored comparison exercise, not a telescope observation or an ephemeris accuracy test.

Astronomy model questions

Can I use these views for observation planning or navigation?

No. They are educational approximations with a bounded orbital fit, projected paths and exaggerated markers. They are not observational predictions or spacecraft guidance.

Are the displayed Moon phases a precise observational forecast?

No. The Moon model uses an idealized constant-month approach. Retain the stated model assumptions and do not interpret the illustration as a measured sky view.

Astronomy & Space Simulator

Positions at the selected date

Two worlds, side by side.

The Moon is always changing.

Travel through the lunar cycle

Estimated upcoming phases