Skip to main content

The Martian Moons

  • Chapter
  • First Online:
Mars and How to Observe It

Part of the book series: Astronomers' Observing Guides ((OBSERVING))


Phobos and Deimos, the two satellites of Mars, are potato-shaped city-sized lumps of rock orbiting in near-circular paths almost directly above the Martian equator. Both moons are made of very dark material and display cratering. Because of their low surface brightness and composition it was once widely considered that both Phobos and Deimos were captured asteroids, but models show that the likelihood of captured asteroids assuming equatorial, near-circular orbits is extremely low. It is possible that they accreted from orbiting debris, perhaps from material blasted from Mars itself by large impacts.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
USD 39.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 49.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

Copyright information

© 2012 Springer Science+Business Media New York

About this chapter

Cite this chapter

Grego, P. (2012). The Martian Moons. In: Mars and How to Observe It. Astronomers' Observing Guides. Springer, New York, NY.

Download citation

  • DOI:

  • Published:

  • Publisher Name: Springer, New York, NY

  • Print ISBN: 978-1-4614-2301-0

  • Online ISBN: 978-1-4614-2302-7

  • eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)

Publish with us

Policies and ethics