Don’t look at the sky. Explore it.

Sidus draws the real sky above you the moment you lift the phone. Constellations, planets, the Moon, the Milky Way and stars at the edge of naked-eye sight — all of them at this hour, above your horizon.

THE PHONE’S ATTITUDE
With sensors on, the sky turns with you. Without them you drag with a finger. Hold the reticle on something and its name and story open.

TONIGHT
How many stars are visible, how full the Moon is, which planet is shining, whether a meteor shower is up. The Bortle scale turns the city’s veil into a number. Optional short tours walk you across the sky.

DISCOVER AND ASK
Search the catalogue, go to a star, read how many years its light has been travelling. Ask answers from tonight’s sky.

SEAL A LOOK
Pin a look to a celestial coordinate: a note, a mood, an optional time lock. Years later, in another city, the phone still takes you to the same point. Memories stay on this device.

TOGETHER
A sky for two. Make a link and they look at the same star. The link carries no GPS — only a sky address, a name and an optional sentence.

THE REAL SKY
Open the camera and the stars settle onto the sky your phone can see. The image never leaves the device. Leave it off and Sidus draws the sky; it works under cloud and indoors.

NIGHT (optional)
The live sky is free. Full catalogue, day/month/year jumps and sky letters need a subscription: weekly, monthly or yearly. Google Play takes the payment.

PRIVACY
No account. No ads. No camera frame is sent anywhere. Location stays on the device to build the sky.

Sidus · HYG catalogue · Sky & Telescope figures · astronomy-engine ephemeris