Why don't Mercury and Venus have moons?

NASA
Astronomy Answers



Most likely because they are too close to the Sun. Any moon with too great a distance from these planets would be in an unstable orbit and be captured by the Sun. If they were too close to these planets they would be destroyed by tidal gravitational forces. The zones where moons around these planets could be stable over billions of years is probably so narrow that no body was ever captured into orbit, or created in situ when the planets were first being accreted.



Return to Top

Copyright
Source: Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Education Center

This web site is a Jan.-Feb. 2018 accessed archive copy of the original version, saved at TYCHOS.info to preserve the web reference. External links may no longer be valid.

Source URL: https://image.gsfc.nasa.gov/poetry/venus/q328.html

According to the “Fair Use” clause of International Copyright Law, the authors declare that the use of the photos, videos and information in this academic research are analyzed for purposes of “criticism, comment, news reporting, teaching, scholarship, or research” according to Section 107 of Title 17 of the US Code.

- Limitations on exclusive rights: Fair use, U.S. Copyright Code.