Celestial Globe of Time

On August evenings the Milky Way shows thickest toward Sagittarius. Mid-August brings a new moon and the Perseids — see that night under "Happenings."

Spin a celestial globe covered in classical constellation art. Wind time back, and stand under the sky of a night in history.

Celestial Globe of Time is a starry-sky simulator built on a real star catalogue. You can enjoy tonight's sky — and, unusually, travel along the axis of time.

■ A globe of constellation art The figures from Urania's Mirror, a star atlas of 1824, are laid over the actual positions of the stars. Constellations you know as lines appear as pictures. The art can be dimmed or turned off.

■ Tonight's sky (free)

• The sky above you, or any of 35 places around the world
• Lines for all 88 IAU constellations, with zodiac constellation art
• The Milky Way, as faint light from real photographic data
• Tap stars and planets to track or pin them
• Point at the sky — the screen shows where you aim your iPad or iPhone

■ Travelling through time (Premium)

• Playback — watch the sky move, from the daily turning to precession
• Jump to an era — the pole star of the pyramid age, the night Galileo found Jupiter's moons, Apollo 11, and more: 18 nights of history
• Stories — Mars in retrograde and the supernova of 1006, told in one-minute guided shows
• Star trails — the sky as a long exposure
• Every constellation artwork — beyond the zodiac

■ Honesty Star positions come from a real catalogue (HYG) and standard astronomical calculations. Where the historical record is thin, reconstructed scenes are labelled as estimates. See "About credits and accuracy" in the app for details.

Premium is a subscription (with a two-week free trial) or a one-time lifetime unlock, and supports Family Sharing. Prices are shown in the App Store in your local currency.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://obbliworks.com/celestial-globe-of-time/privacy