🌏 Singapore sees almost the whole sky

The one thing about observing from 1.3° north that no darker, higher, more famous observatory can match. Science Centre Observatory, Jurong.
of the entire sky is visible from SCOB over the course of a year

Why — in one line

Standing at the equator, the Earth’s axis lies flat along your horizon. Both celestial poles sit on the horizon rather than up in the sky, so as the year turns, everything comes past — the far north and the far south alike. Move away from the equator and you tip a cap of sky permanently below your horizon, and it never comes back. From latitude φ, every star south of declination φ − 90° is lost to you forever.

The declination you can reach

Each bar is the slice of sky a site can ever see. Ours runs almost the full width.

Things you cannot see from both hemispheres — except here

The evidence, object by object

Highest each object ever climbs, at each site. Negative means it never rises at all. Computed live from each site’s latitude — nothing here is a stored number.

What this is actually good for

Say it to visitors. Someone who has only stargazed in Europe or North America has never seen the Southern Cross, Omega Centauri, the Magellanic Clouds or Canopus, and never will from home. Someone from Australia or Chile has never seen Polaris or the Big Dipper. Standing on this deck, you can show them both halves of the sky in one night. That is a genuinely rare thing and it is worth saying out loud.

Say it to yourself when the sky is bad. Jurong’s light pollution is real and this page does not pretend otherwise. But light pollution is a problem you can partly work around — with the Moon, the planets, double stars, and brighter clusters. Latitude is not. An observatory at 51° north can build a perfect dark site and still never, on any night, in any century, see 47 Tucanae. We can see it from a car park.

It also explains our calendar. Because everything is on the move past us, our showpiece list turns over faster than a high-latitude observatory’s. Orion in February, Omega Centauri and the Southern Cross around May, the Milky Way core almost overhead from June to September, Andromeda late in the year. Nothing is permanent, and nothing is out of reach.

Every figure on this page is computed in your browser from each site’s latitude and each object’s J2000 declination, using the standard result that an object of declination δ culminates at altitude 90° − |φ − δ| and never rises when that is negative. The visible-sky fraction is the area of the spherical cap around the unreachable pole, (1 − cos|φ|)/2. Refraction (about half a degree at the horizon) is ignored, which is why one or two objects sit right on the boundary — see the notes above. Current altitudes come from the site's own astronomy engine.
Object coordinates: standard J2000 positions. Site latitudes: SCOB 1.3342°N; Mauna Kea 19.83°N; Roque de los Muchachos, La Palma 28.76°N; Greenwich 51.48°N; Paranal 24.63°S; Sydney 33.87°S.
Learn more (opens external sites): NASA Skywatching · In-The-Sky.org planner.
Companion pages: constellation stories & 3D depth · why the Milky Way is hard to see here · this month’s sky.
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