Until recently many astronomers believed that asteroids travel about the solar system unaccompanied by satellites.
Topic
Do asteroids have satellites (moons) orbiting them?
Framework
Old / New
Main Point
Although astronomers used to think asteroid satellites were unlikely or impossible, recent observational evidence has made the existence of asteroid satellites more plausible—though conclusive proof is still needed, such as a clear photoelectric record of a "well-behaved" secondary occultation. (—first sentence highlights the "old" view; the rest of the passage describes new evidence and what standard of proof is still required.)
P1: Old Assumptions about Asteroid Satellites
Astronomers mostly used to believe asteroids didn’t have satellites, assuming such systems would be unstable. However, theoreticians point out that small bodies CAN support satellites, given the right conditions.
P2: New Observational Evidence Hints at Satellites
Recent observations suggest asteroid satellites might be real—sometimes, when asteroids pass in front of stars, astronomers see an extra brief dimming, which could mean a satellite is blocking the star as well.
P3: The Herculina Event and Growing Reports
The most convincing case happened in 1978 with asteroid Herculina: there were two separate dips in a star’s brightness as Herculina passed, indicating a probable satellite. These observations fit theoretical possibilities. After this, reports of possible asteroid satellites spiked, but there are probably now too many sightings for them all to be real.