Saturn shines brightest in May

The ringed world shows off to telescope users.
By | Published: May 2, 2014 | Last updated on May 18, 2023

Saturn on April 6, 2014
Saturn’s rings open wider this year than at any time since 2005, offering observers great views through any telescope.
Anthony Wesley
On May 10, at 2 p.m. EDT, Saturn reaches opposition — the point in its orbit when it lies opposite the Sun as seen from Earth. The planet then appears as a bright yellowish object at magnitude 0.1 in the constellation Libra the Scales. In the Northern Hemisphere, that star pattern rises in the southeast at sunset.

As you might guess, opposition means the planet rises at sunset, climbs highest in the south around 1 A.M. local daylight time, and sets as the Sun comes up. Opposition also brings Saturn closest to Earth, so it shines brightest for the year (at magnitude 0.1). During times of good seeing (atmospheric steadiness), an observer can pick out the more prominent features of the globe and rings through a 3-inch telescope.

Saturn reaches opposition and peak visibility May 10, 2014.
Saturn reaches opposition and peak visibility May 10, when it shines brightly in the southeast after darkness falls.
Astronomy: Roen Kelly
There’s no rush to do this. An apparition (observing season) of Saturn spans a bit more than 10 months. The current one began in late November 2013 when Saturn emerged from the solar glare in the morning sky. The planet will remain visible until October, when it will sink too low in the west after sunset for useful observations.

Opposition marks the peak time for observing any outer planet. Not only does a distant world then remain visible all night and shine brightest, but it also appears largest through a telescope. On May 10, Saturn’s disk measures 19″ across while its stunning ring system spans 42″. [NOTE: the ” symbol is the way astronomers abbreviate arcseconds, a way to measure the apparent sizes of celestial bodies. One arcsecond equals 1/3,600 of 1°.] The rings tilt 22° to our line of sight and reveal exquisite detail through any scope. Although the planet shrinks as we get further from opposition, the change is barely detectable — the ring system’s diameter drops only 0.3″ by month’s end.

Saturn also has several moons that show up through small instruments. Any telescope reveals 8th-magnitude Titan, while a 4-inch scope brings Tethys, Dione, and Rhea — all 10th-magnitude satellites — into view.

Saturn in May 2014
The ringed planet appears against the backdrop of Libra at its peak this year. Saturn outshines the constellation’s brightest stars, magnitude 2.6 Zubenelgenubi (Alpha [α] Librae) and Zubeneschamali (Beta [β] Librae).
Astronomy: Roen Kelly
Astronomy magazine Contributing Editor Mike Reynolds loves showing people Saturn. “Some people seeing it for the first time think it’s fake or a slide,” he says. “In reality, it’s one of the most amazing sights a telescope will reveal. And again this year, with the rings pretty wide open, will be a real opportunity for amateur astronomers to educate the public about how the planets move.”

FUN FACTS ABOUT SATURN

  • Saturn is 95 times as massive as Earth.
  • From Saturn, the Sun appears 1 percent as bright as from Earth.
  • Saturn’s polar diameter is only 89 percent of its equatorial girth.
  • The rings tilt 27.3° with respect to Saturn’s orbit.
  • More than 800 Earths would fit inside the ringed planet.
  • It is the only planet whose density is less than water. If you could find an ocean big enough, Saturn would float.
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