Each dot slides at its Gaia DR3 proper motion. Radial motion and slow changes of proper motion are ignored, so time stops at ±2,000 years.
How it is computed: each star moves along a great circle of the sky at its Gaia DR3 proper motion (east and north parts, with cos δ). Ignored: motion toward or away from us, and the slow change of proper motion that it causes over tens of thousands of years. At ±2,000 years this puts the worst cases, Kapteyn's and Barnard's Star, up to about 15% off their shown shift; most stars much less. The background picture does not move: it is the sky as SPHEREx saw it in 2025–2026.
Sky: SPHEREx DR1 all-sky HiPS, NASA/SPHEREx, Caltech/IPAC (NASA/IPAC Infrared Science Archive); false colour from 9 of its 102 wavelengths (blue 1.1, green 2.1, red 3.5 µm). Stars: ESA/Gaia/DPAC, Gaia DR3 (Gaia Collaboration, Vallenari et al. 2023). WISE 0855−0714: Kirkpatrick et al. 2021 (Spitzer). Luhman 16: SIMBAD. Blinks and measurements: Fazari, from SPHEREx images. This page uses the NASA/IPAC Infrared Science Archive, which is funded by NASA and operated by Caltech.