Can the Moon eclipse Venus?

  • The title basically says it all. As seen from the Earth, is it possible for the Moon to eclipse Venus (or any other planet) or are the orbits inclined such that this never happens?



    If such an eclipse is possible, is it a frequent or infrequent event? How would I find out when the next one occurs?


    I'm pretty sure that the answer is yes. I'm guessing that people don't pay it any attention because it isn't visually interesting the way that lunar and solar eclipses are.

    https://apod.nasa.gov/apod/ap980513.html is a picture of such an occultation which also happens to be a double occultation with Jupiter. https://solarsystem.nasa.gov/resources/472/lunar-occultation-of-venus/ is another. https://www.skyandtelescope.com/observing/moon-flys-by-catalina-occults-venus-on-dec-7th120220150212/ is an article on an occultation. With a little work, you should be able to find a list of occultations (I couldn't but I didn't search very long).

    http://asa.usno.navy.mil/SecA/occns.html is the only real "official" list I could find and it only goes through next year.

    @barrycarter, write answers!

    Note that occultation is a bit different to an eclipse, since in occultation the Moon merely blocks our view of the occulted body, whereas in an eclipse a shadow is cast: the Earth's shadow on the Moon in a lunar eclipse, and the Moon's shadow on the Earth in a solar eclipse.

    @PM2Ring I don't find that a particularly useful distinction since blocking the light from one body with a second will always create a shadow, even if it's not noticeable to the human eye.

    @CannonFodder It's a useful distinction because the shadow in an eclipse is a fundamental feature of the phenomenon. Whereas with an occultation the occulted body is not obscured by a shadow cast by the occulting body. E.g. if a Full Moon occults Jupiter, their shadow cones are pointing away from Earth, and the Moon's shadow certainly doesn't create a solar eclipse on Jupiter. But I guess if it's aligned correctly, and you had a good telescope, you could see our Moon (and the Earth) transiting the Sun from a Jovian orbit.

    Note that in the ordinary sense of an eclipse being **a transit across the Sun and involving the Moon** (thus: a solar eclipse when viewed from Earth, or a lunar eclipse when viewed from the Moon), it is never possible for the Moon to eclipse Venus, since the Moon cannot pass between Venus and the Sun.

  • Mick

    Mick Correct answer

    4 years ago

    As @Donald.McLean said in comments, the answer is yes, the Moon can and does occult the other planets in the Solar System. When something apparently big (like the Moon) passes in front of something apparently small (another planet) it's called an occultation. (I say apparently because from our perspective the Moon appears larger than the planets.)



    The planets lie* in the ecliptic plane whereas the Moon's orbit is inclined at about 5° to the ecliptic plane, so the Moon crosses the ecliptic plane twice each orbit, so it's not as frequent as it would be if the Moon's orbit were in the ecliptic plane.



    Occultations of the planets by the Moon can be found here. There is also software (Occult) that you can use to generate your own predictions.



    * Although the planets are said to lie in the ecliptic plane, this is a generalisation - they actually have orbits that are within a few degrees of the ecliptic "plane".


    It's pretty common to use "big" to indicate angular extent rather than physical size, but props for being explicit here.

    "Occult", from the Latin *occultus*: clandestine, hidden, secret.

    _"The planets lie in the ecliptic plane whereas the Moon's orbit is inclined at about 5° to the ecliptic plane"_ The planets also have inclined orbits, Venus for example has 3.4° inclination relative to the ecliptic plane.

    @JiK Yes, I may have oversimplified a bit.

    Given the moon has an angular diameter of 0.5°, about 10% of it's orbital inclination, passing the elliptic plane involves an extended period of potential occlusion each half orbit.

    Next question: how long until the moon is far enough away that the answer becomes a no? Trick question because the sun will already be a red dwarf that slagged Earth?

    @JiK You're correct in saying that Venus' inclination is 3.4 degrees, but, because of its proximity to Earth, it can be over 7 degrees away from the ecliptic as viewed from Earth.

License under CC-BY-SA with attribution


Content dated before 7/24/2021 11:53 AM