Live network median
—mag/arcsec²
Waiting for current station readings
The whole reserve
The network at a glance
Network typical sky
—mag/arcsec²
Median of every site's typical night
Sites online
—sensors
Darkest site
—
Bortle 1–3 sites
—
Sites reaching genuinely dark-sky classes
Nights recorded
—site-nights
Across the whole network
Datapoints stored
—readings
Individual sensor readings in the network archive
Brightest site
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Where we watch
The station map
See how darkness changes across the reserve, interpolated between each station's live, latest-night or typical reading. Adelaide is included as an illustrative typical city comparison, not a live tracking station. Higher values mean darker skies. Click a station to visit its site, or zoom in to reveal site names.
BrighterDarker
Station reading
Adelaide · typical 18.0
Map data © OpenStreetMap contributors
Sensor network
Visit a station
Twenty monitoring sites across 3,200 km² of protected night. Each has its own dashboard of nightly readings, trends and insights.
The long view
The reserve through the seasons
Each dot is the network median across all reporting sites for one night — using only moon-free readings so moonlight does not distort the public trend.
Insights from the network
Understand the numbers
How dark is dark?
Magnitudes per square arc-second
Our sensors measure the brightness of the night sky in magnitudes per square arc-second (mag/arcsec²) — the standard unit used by astronomers. It runs backwards from what you might expect: bigger number = darker sky.
The scale is logarithmic: every 5 magnitudes is a 100× difference in light. So a sky at 22 mag/arcsec² isn't a little darker than an 18 mag/arcsec² city sky — it's about 40 times darker.
The Bortle scale
The Bortle scale describes what you can actually see, from Class 1 (the darkest skies on Earth) to Class 9 (inner-city). The badges show how many of our sites reach each class.
About
The River Murray International Dark Sky Reserve
Covering more than 3,200 km² of South Australia's Mid Murray region — from Bow Hill to Blanchetown along the river, and west to the foothills of the Mount Lofty Ranges — the River Murray International Dark Sky Reserve was Australia's first, accredited by the International Dark-Sky Association in October 2019. Its core at Meldanda, near Cambrai, records skies that regularly reach Bortle Class 1–2: nights so dark the Milky Way casts a shadow.
Project Nightwatch turns the reserve's scientific monitoring into something everyone can explore. Unihedron Sky Quality Meters measure the glow of the night sky every minute, while infrared cloud sensors track conditions overhead. And the long game matters: the night sky brightens by up to a magnitude around solar maximum, so the reserve is building an 11-year dataset across a full solar cycle. The district's best reading — 21.96 mag/arcsec², recorded near Swan Reach in 2016/17 — shows what solar-minimum skies can do.
The technical-preview network currently reads the same SQM-LE TCP protocol from the project’s data-generator app that physical Unihedron units will use. Each station endpoint can be replaced independently as real equipment comes online. Following standard practice in light-pollution research, readings above 22.0 mag/arcsec² are excluded as likely dark-cloud or obstruction artefacts. Rankings, Bortle classes and long-term trends also require the Sun to be at least 12° below the horizon and the Moon to be below the horizon or less than 25% illuminated. All other readings remain available in station detail and protected raw feeds. Sky brightness readings are zenith measurements in mag/arcsec²; timestamps in charts are local time (UTC+10:30).
For developers
Public data API
Use the published network and station data in your own scripts, notebooks or visualisations.
Open, read-only access
The API returns JSON and does not require a sign-in or API key. It is versioned under
/api/v1 and follows the same published data and analysis policy as this site.
Sky brightness is measured in mag/arcsec² — higher values mean darker skies. Sensor sample timestamps are UTC; station night dates are local dates. This is a technical preview, so the data and analysis may change as the network develops.
Useful starting points
GET /api/v1/networkNetwork summary, aggregates and trends.GET /api/v1/sitesList of public dark-sky tracking stations.GET /api/v1/sites/{site_id}Summary and latest published results for one station.GET /api/v1/sites/{site_id}/nightsNightly results, with optionalfromandtodate filters.