VLBI
A technique using multiple radio telescopes separated by vast distances to create extremely high-resolution images of distant cosmic objects.
Very Long Baseline Interferometry is an astronomical method combining radio signals from telescopes located thousands of kilometers apart to achieve angular resolution far exceeding what any single telescope could provide. By analyzing the time delays between signals arriving at different sites, astronomers can map fine details of distant sources like active galactic nuclei, pulsars, and other compact objects.
What this means in real life
Astronomers using radio telescopes in Europe, Asia, and North America simultaneously observe a distant quasar, then combine the data to create an image with resolution equivalent to a telescope the size of Earth itself.
What it isn’t
It is not a single large telescope or a simple network of nearby radio dishes. Rather, it requires precise synchronization of geographically separated instruments and sophisticated data processing to synthesize observations into high-resolution images.
Commonly misused online
Social media sometimes conflates it with general radio astronomy or assumes it produces optical images; in reality, it creates radio-wavelength maps requiring specialized interpretation and cannot directly photograph visible light.