Deep Sky Monitor From Curiosity to Cosmos.

Settings

Personalise Deep Sky Monitor: UTC or local time, 12- or 24-hour clock, start page, star-map style, observing location and object images. Changes apply immediately and are saved in this browser only (other people and devices keep their own settings), except the Image cache section at the bottom, which is saved on the server for everyone.

Time

Show times inThe header clock and every date and time on the site. You can also click the header clock to switch.
Clock format24-hour (14:05) or 12-hour (2:05 PM).

Start-up

Default pageWhat opens when you visit the dashboard's home address.
Default spacecraftSelected when the Space Observatories page opens. A link like ?sat=iss still overrides it.

Sky maps

Deep-sky backgroundRealistic sky: real photographs of the whole sky (Mellinger and DSS colour surveys) that sharpen as you zoom; needs a good connection. Star chart: the lighter drawn chart, which the options below style. The button on the chart switches too.
Show starsThe real star field behind the deep-sky star chart.
Star brightnessDimmer stars make the satellites and sources stand out more.
100%
Milky Way bandThe plane of our galaxy (±10°) on the deep-sky star chart, where most pulsars lie. (The realistic sky shows the real Milky Way.)
Constellation linesStick figures on the deep-sky chart.
Constellation namesMajor names when zoomed out; all 88 from about 2× zoom.

Object images

Images per objectHow many images the Explore Deep Sky image carousel shows: the best photos (Webb, then Hubble, then other NASA, then Wikipedia) and the telescope survey view. More images take a little longer the first time an object is opened.

My location

Observing locationUsed only in your browser to show whether each deep-sky source is above your horizon and when it rises or sets. Never sent to the server.

Image cache server-wide

Carousel images are downloaded once and kept on this server, so later views are instant and work when NASA or Wikipedia is slow. Photos are stored carousel-sized only (at most 1,000 px wide, WebP); the large view loads the full-resolution original straight from NASA or Wikimedia. These settings apply to everyone using this dashboard. Now: 70 image(s), 4.7 MB of 500 MB (1% used).

Keep downloaded images forAfter this, an image is downloaded again the next time it is shown, and the weekly upkeep job deletes older files. 7–365 days.
Remember each object's image list forWhich photos NASA and Wikipedia have for an object. After this, they are searched again, so newly published images (e.g. a new Webb image) appear. 1–90 days.
Use at mostDisk space for downloaded images. Beyond it, the daily tidy-up (09:20 UTC) removes the least recently viewed until the cache is back under 90%; they are downloaded again if someone views them. A lower limit applies as soon as you save. 50–20,000 MB.