Is this real asteroid data?

Yes. The approaches come from NASA/JPL's Center for Near-Earth Object Studies close-approach database, gathered by the site's pipeline and refreshed on a schedule. The countdown itself ticks live in your browser.

Does the ⚠ badge mean an asteroid will hit Earth?

No. "Potentially hazardous" is NASA's classification for objects over roughly 140 m that can come within 19.5 lunar distances — it describes size and orbit, not a predicted impact. Every approach shown is a miss.

How is this different from the Asteroid Watch saver?

Asteroid Watch is a radar scope plotting all upcoming approaches at once. This saver is the clock view: one big countdown to the very next flyby, with the following three queued.

Does it need an API key or work offline?

No key — the pipeline reads NASA's public data. It does need an internet connection to load the feed; if the feed is missing it tells you exactly which pipeline flag to run.

Yes — free, no download, in your browser. ESC exits at any time.

Asteroid Close-Approach Clock Screensaver

The Asteroid Close-Approach Clock counts down to the next near-Earth asteroid flyby from NASA/JPL's close-approach database — the rock's name, miss distance in lunar distances, speed and size range, with the next three approaches queued below. It's free, needs an internet connection, and ESC exits.

How the Asteroid Close-Approach Clock screensaver works

The site's pipeline gathers upcoming close approaches from NASA/JPL's CNEOS database into content/asteroids.json; the saver re-reads it every hour.

It picks the next approach still in the future and runs a T-minus clock — days, hours, minutes, seconds — ticking four times a second.

The feed lists approach dates to the day, so the clock targets 12:00 UTC on the listed date; the footnote on screen says so.

A ⚠ badge marks rocks NASA classes as potentially hazardous — a size-and-orbit category, not an impact warning; every listed approach is a safe miss.

A worked example

With 2025 AL2 up next, the screen reads T−21:03:44:09 under its name and ⚠ badge, with the stats line miss 2.19 LD · 12.4 km/s · Ø 75–168 m and three later flybys queued below. Pair it with the Asteroid Watch radar in Multi-view — the radar shows the whole field while this clock counts down the single next event.

Settings & tips

Show upcoming queue — turn the three-row list of following approaches off for a cleaner, countdown-only screen in small Multi-view cells.

Frequently asked questions

Is this real asteroid data?: Yes. The approaches come from NASA/JPL's Center for Near-Earth Object Studies close-approach database, gathered by the site's pipeline and refreshed on a schedule. The countdown itself ticks live in your browser.
Does the ⚠ badge mean an asteroid will hit Earth?: No. "Potentially hazardous" is NASA's classification for objects over roughly 140 m that can come within 19.5 lunar distances — it describes size and orbit, not a predicted impact. Every approach shown is a miss.
How is this different from the Asteroid Watch saver?: Asteroid Watch is a radar scope plotting all upcoming approaches at once. This saver is the clock view: one big countdown to the very next flyby, with the following three queued.
Does it need an API key or work offline?: No key — the pipeline reads NASA's public data. It does need an internet connection to load the feed; if the feed is missing it tells you exactly which pipeline flag to run.
Is it free?: Yes — free, no download, in your browser. ESC exits at any time.

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