Space Explorer SIDEREAL

SIDEREAL · SPACE EXPLORER

SIDEREAL, a space simulator you explore yourself

SIDEREAL is a 3D space simulator for browsing planets, moons, nearby stars and galaxies. Move between a solar system map, a size comparison of eleven bodies, and real astronomical photographs to get a feel for the scale of space and how different objects actually look. It runs in the browser on MEINPLAY — no install, no account.

In a textbook, Jupiter and Earth are printed side by side, which makes them easy to remember as similar in size. How large a bright star in the night sky really is, or how our galaxy differs from another, is hard to grasp from a single photograph. SIDEREAL turns those questions into something you do by moving and comparing on screen. Rather than watching a fixed video to the end, you can stop at whatever catches your interest, zoom in, and keep the conversation going.

What you can do

• Navigate to the eight planets of the solar system and several moons as destinations
• Compare the size of eleven bodies — the Moon, the eight planets, the Sun and Betelgeuse
• Browse a 3D map covering the solar system, nearby stars, the Milky Way and neighbouring galaxies
• View observation photographs and constellation figures with their sources credited (NASA, ESA and others)

Seeing planet sizes for yourself

The size comparison starts at the Moon and runs through Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, Jupiter, the Sun and Betelgeuse. That order is smallest to largest — not distance from the Sun. Pointing out that difference at the start of a lesson helps avoid confusing where a planet sits with how big it is.

Each screen shows the type of object, its mean diameter, and its diameter relative to Earth. Set the comparison to the previous object to watch the increase step by step, or fix it to Earth to measure every planet against one yardstick. Look at bodies of similar size such as Venus and Earth first, then jump to Jupiter or the Sun to see how far the gap opens. Pausing the automatic tour and asking people to predict before revealing works well here.

A note on what the numbers mean: the ratio refers to mean diameter of the body itself, not volume or mass. Saturn’s ring span is not counted in its diameter. If Earth is nearly invisible beside a giant star, that is the honest result of keeping one scale. The spacing between objects is arranged for comfortable viewing and is not real distance in space. Betelgeuse varies in size and carries large estimation uncertainty, so it is drawn as a model at roughly 700 solar radii — worth reading aloud alongside the visual.

Using it in a science lesson

SIDEREAL works as an audiovisual aid that a teacher or parent narrates. It fits well with elementary science topics: identifying members of the solar system, comparing Earth and the Moon, or opening a question about how stars and planets differ. It is not a certified curriculum resource or an assessment tool with measured learning outcomes, so choosing which scenes to use for your objective and your students is the right approach.

Before class, open it on the device you will present from and check text size and motion. On an interactive whiteboard or projector, use full screen, and pause the automatic movement while you talk so attention stays on the observation. High-resolution photographs can take a moment to load the first time, so preview the ones you plan to use. Sound is optional — the core exploration and size comparison work in silence.

A 15-minute activity: were our guesses right?

• Predict (3 min) — write down the size order of the Moon, Earth, Jupiter and the Sun, and guess how much bigger Jupiter is than Earth.
• Observe (5 min) — fix the comparison to Earth and step through Venus, Jupiter and the Sun. Read the diameter ratio and say what differed from the guess.
• Extend (4 min) — go back to the solar system map and look at where the planets sit. Discuss whether the spacing in the comparison view and the distances on the map use the same yardstick.
• Wrap up (3 min) — record one new fact and one remaining question. Next time, look up the source of a related photograph.

This is a suggestion, not a script. With younger students, start from names and visible differences; with students who have studied ratios, extend into the difference between diameter and volume. Asking them to say what they compared against matters more than memorising the answer.

Exploring at home

At home it works as a short trip rather than a lesson. Pick a destination together, look at the photograph, and let the questions come from whatever surprises you. Because you control the view, a child who wants to stay at Saturn’s rings for five minutes can. Mean diameters and Earth ratios are on screen, so an adult does not need to prepare facts in advance.

Real photographs versus 3D models

Two different kinds of image appear here. Observation photographs come from telescopes and probes and carry their source. The 3D bodies you fly around are models — useful for understanding shape, relative size and position, but not a photograph of a surface. Where no real image exists, nothing is presented as if it were one. Keeping that distinction clear is part of using the tool honestly.