New asteroids and cosmic explosions are found slowly, a handful at a time
The old claim turned out to be wrong and was rejected by evidence.
TaughtFinding a new asteroid, or catching a supernova as it flares, is painstaking work: an astronomer comparing images, spotting a moving dot or a new point of light, confirming it night by night. Discoveries come in ones and tens, and the vast majority of the sky's changes pass unseen.
NowOn 30 June 2026, the NSF–DOE Vera C. Rubin Observatory began its 10-year Legacy Survey of Space and Time, imaging the entire southern sky every few nights. In just six weeks of early optimization runs it had already found over 11,000 new asteroids, and in full operation it issues up to about 7 million alerts of changes in the sky every single night.
What actually happened
Rubin pairs the largest digital camera ever built (3,200 megapixels) with a telescope designed to sweep the whole visible sky on a rolling few-night cadence, revisiting each patch around 800 times over the decade. Software compares each new image to the last and flags anything that moved or changed, automatically.
The change is one of scale so extreme it becomes a change in kind. Rubin is expected to catalog millions of new solar-system bodies, more than every previous telescope and survey in history combined, and to catch supernovae, flaring black holes, and other transients by the millions, alerting other telescopes within minutes to chase the fleeting ones.
The honest framing: careful individual discovery still matters, and the flood of alerts is itself a new problem, too large for humans to inspect by hand. But the specific old picture (that the sky's asteroids and explosions are found slowly, a few at a time) was retired when Rubin's survey switched on in 2026.
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Who was taught this
Still standard through 2026, so anyone who finished school between 1950 and 2026 learned the earlier version.