Telescope Resolution Sandbox

Explore how aperture, wavelength, and atmosphere limit what we can resolve

Station Card (PDF)
Simulated View (Hubble Space Telescope)
RESOLVED - Stars clearly separated
Diffraction Limit
0.047
arcsec
Effective Resolution
0.047
arcsec
Binary Separation
0.10
arcsec
Aperture
2.4
m
Aperture (D) 2.4 m
7 mm (eye) 10,000 km (EHT)
Wavelength 550 nm (Visible)
Seeing 1.0"
0.5" (excellent) 3.0" (poor)
Binary Star Separation
Separation 0.10 arcsec
0.01" (very close) 10" (wide)
Optical Telescopes
Radio / Interferometers

The Rayleigh Criterion

Two point sources are just resolved when the central maximum of one Airy disk falls on the first minimum of the other.

Larger apertures collect more light AND resolve finer details. Space telescopes avoid atmospheric blurring entirely.