Astronomers using the Hubble Space Telescope last month captured a rare moment as four of Saturn's moons passed in front of the planet (as seen from Earth) within a short period of time.

The moons - Titan Mimas, Enceladus and Dione - each cast their own shadows onto the planet's gassy cloud tops as they drift past. Here's more on the event and the photos.

Saturn's iconic rings appear very narrow. They are approaching a period of edge-on orientation relative to Earth, when they all but disappear from view. They will be precisely edge-on on Aug. 10 and again on Sept. 4. It's something that occurs once every 14 or 15 years, and it's called a ring-plane crossing.

These transits of Saturn's moons across the planet's disk tend to occur during these ring-plane crossings because most of the moons orbit in the same plane as the rings. 

The images were shot by Hubble on Feb. 24, when Saturn was about 775 million miles from Earth. The Hubble folks have assembled views of Saturn into a video of the transits.

Pale yellow Saturn is visible in Maryland skies on clear nights this month. Just past opposition - its closest approach to Earth this year and the best time for a look through a telescope - it is rising in the east around 7 p.m. and is high in the southeast at midnight.