The sky, in layers
The whole sky from public surveys, in layers you can switch on and off, with a mark on every target I hold frames of. Drag to move; scroll or pinch to zoom. These are pictures for viewing, not for measurement.
Overlays
Bigger marks mean more hours. Marks only, not the images. Click or tap one.
View
Your scopes
The night's plan
Your frame
A frame is one image from a telescope. Drop a FITS or ASDF file (two standard astronomy file types) on the sky, or pick one here. It stays on your computer: your browser reads it, nothing is uploaded and nothing is kept. More on that.
Matches this frame's stars against star positions from Gaia, a space telescope, here in your browser, and slides the frame into place. It asks this site's star files for the patch of sky named in the frame's header, and sends nothing else.
Ask about the sky
Answers are written by Claude, an AI model from Anthropic, and can be wrong. Your question goes to Anthropic, so please don't type where you live. What is sent.
Your location, for what's up tonight (optional)
Rounded to about 11 km and sent only to our server, which works out altitudes. Anthropic gets the altitudes, not your place. Not saved: it's gone when you leave the page.
Drop your frame here. It stays on your computer.
Wavelength, on a stretched (log) scale: each big step is ten times longer light. A nanometer (nm) is a billionth of a meter; a micron is a thousandth of a millimeter.
Loading the list of layers...
Licenses and credits for every layer are below.
What this is
Each layer is a map of the whole sky made from a public survey (a telescope project that scans large parts of the sky), or from star data. I converted each one into picture tiles and serve them from this site.
The tiles follow two open standards. HEALPix cuts the sphere of the sky into equal-area cells, and each cell splits into four smaller ones as you zoom in. HiPS (Hierarchical Progressive Surveys) stores a map as tiles on those cells, so a viewer fetches only the tiles for the patch on your screen.
- Not every patch is deep. Each layer says how much of the sky it covers, and where a survey has nothing, the layer is see-through. Some layers stay soft however far you zoom, because that is all the survey resolved.
- Pictures, not measurements. The tiles are converted from the originals and processed for display, so their brightness is not the original measured value. For any number, use the survey's own data.
- No single frames here yet. A frame is one exposure from a telescope. My own frames are not on this map; see below. You can put one of yours on it, for yourself: it stays on your computer.
The marks for my targets
The marks show targets with frames in my catalog: 125 targets and 629,387 frames, as of . A mark is a place on the sky with a count of frames behind it, not the images themselves. When my frames are converted, they will become a layer here too.
The sky map has the same targets as a table you can search, and explains the three stages: captured, processed and published.
Licenses and credits
Some layers are NonCommercial, and some are ShareAlike as well. The narrowband survey is CC BY-NC-SA 4.0 (NonCommercial, ShareAlike). The map made from Gaia star data and the layers from the Planck space telescope are CC BY-NC 3.0 IGO (NonCommercial). The table lists the license of every layer.
The tiles are converted from the originals and processed for display; they are for viewing and not for measurement. The tiles made from a ShareAlike layer are offered under that same license.
| Layer | Credit | License | Source | Contact with the source's team |
|---|
Part of a survey team? If you'd like a layer changed, credited differently or taken down, write to me at hello@skycruncher.io.
The viewer is Aladin Lite 3.8.2, by the Centre de Données astronomiques de Strasbourg (CDS). I serve an unmodified copy from this site. Its license file is the LGPL-3.0 (LICENSE, which builds on the GPL-3.0), and its README names the GPL v3.0. The source is on GitHub.
Star positions for the Solve button come from Gaia Data Release 3, a mission of the European Space Agency (ESA), processed by the Gaia Data Processing and Analysis Consortium (DPAC): Gaia Collaboration, Vallenari, A., et al. 2023, A&A 674, A1. Gaia data are under CC BY-NC 3.0 IGO (NonCommercial), passed through unchanged and split into patches of sky for this site.
The target list is my own, from the sky map. Other software on this site is listed in Credits and licenses.