What It Is
Astera is a stargazing and astronomy education app that shows the sky above you the moment you open it. It has three parts: a sky map for looking up, space explorations that teach through questions, and an observation journal for what you saw. There is no sign-up, no ads and no payment.
The Problem
Looking up at the night sky, it is hard to know what a given star is. There are many star map apps, but most stop at naming things and never explain why the sky looks the way it does. School astronomy units, on the other hand, sit far from the real sky, making it hard to check what you learned against the stars.
Astera brings seeing the real sky and learning how it works into one app. In class, everyone can explore the same sky together.
Who It Is For
- People curious about the night sky: people who want the names and positions of the stars and planets they can see right now
- Observers heading out to see stars: people who want to find stars while protecting their night vision and keep a record of what they saw
- Science teachers and students: classrooms that want to teach and learn astronomy connected to the real sky
Core Flow
- Look at the sky: open the app and raise your phone; the map follows the direction you point.
- Find an object: tap a star or planet to see its name, brightness, distance, direction and rise and set times. If it is off-screen, an arrow at the edge shows the way.
- Preview: change the date, time or place to see the sky on another day or somewhere else.
- Explore: work through questions such as why the Moon changes shape by moving diagrams yourself.
- Record: log the object, the time, and whether you saw it in the real sky or explored it in the app, with notes.
Key Features
- Your sky right now: a star map that follows the orientation sensor. Faint illustrations, like those in old star atlases, sit behind the constellations so the shapes stand out at a glance.
- A sky close to reality: choose a city, suburbs or dark countryside as your site, and the map shows only the stars visible there. Zoom in to reveal about 69,000 stars too faint for the naked eye.
- Red night mode: every screen turns dark red to protect eyes adjusted to the dark. A focused observing view hides the menus.
- Three space questions: why the Moon's shape changes, whether stars in one constellation are really close together, and when the starlight you see began its journey, each explained at "Simple" and "Detailed" levels.
- Lesson scenes and activities: open a lesson scene with a fixed place, time and direction so everyone sees the same sky. Activities run from question to prediction, hands-on exploration, explanation and a summary in your own words, and teacher guides include learning objectives, time needed and common misconceptions.
- Observation journal: export entries as text or delete them.
- Five languages: Korean, English, Japanese, and Simplified and Traditional Chinese, with star and constellation names in the language you choose.
Product Decisions
- Never confuse real and simulated: when you change the date or place, "Simulated observation" stays at the top of the screen, so students never mix up tonight's sky with a preview.
- Draw only what can be seen: rather than filling the sky for effect, the map shows only what the naked eye can see from that site. That reduces the letdown when the real sky looks different from the app.
- Say what was simplified: the exploration diagrams note what was scaled down or simplified, and stars with large distance uncertainties are marked as such.
- Every feature without location: pick a city and every feature works without location permission. The journal and location stay on the phone.
- Wrong explanations can be hidden at once: explanations and activities are refined through review by astronomers and teachers. If an explanation turns out to be wrong, that item can be hidden without an app update.
- Official names for stars: Korean star and constellation names follow the Korean Astronomical Society's terminology.
Revenue Model
Free, with no ads or payments. The first step is confirming that it is a useful tool for both classrooms and individual observers.
Next Hypotheses
- Whether teachers use lesson scenes in real classes, and which activities get used most.
- Whether people who start with the sky map move on to the explorations and read about how things work.
- Whether people who keep an observation journal open the app again on the next clear night.
Contact and privacy
- Contact: reach us on the contact page.
- Privacy: there is no sign-up, so there is no account to delete. Your journal and location are stored only on your phone; the only data that leaves it is crash information (which you can turn off in settings) and requests for settings. See the privacy policy for details.