April is Global Astronomy Month, and as a highlight, the “Lord of the Rings” is back prominently in the night sky! This past weekend, Saturn reached opposition, when it is closest to the Earth in its orbit. Opposition means Saturn is directly opposite the Sun in the sky, so it rises in the east at sunset and sets in the west at sunrise – meaning it will be in the sky all night long! Saturn is also the only planet visible before midnight in April. But the beautiful ringed planet will be looking even brighter that it has been for the past few months.
Special thanks to Efrain Morales Rivera for sending us this montage of Saturn images, showing a current view of Saturn in the middle and the ringed planet at oppositions from the last six years.
Around opposition there is a phenomenon known as the Seeliger Effect, which might actually be a couple of different effects combining to enhance the brightness of Saturn: Since the Earth is smack dab in the middle of the Sun and Saturn, sunlight is coming from directly behind us and directly at Saturn. And there’s also the phenomenon called coherent backscattering, which is where if you shine a beam of light at something that is made from a lot of separate particles (like Saturn’s rings) the light is reflected back with greater intensity from the direction directly opposite the beam. The middle image of Saturn in the montage above reveals brighter rings from the Seeliger Effect, as well as highlighting the ‘Serpent storm’ in the northern hemisphere.
This is also a great time to try and see some of Saturn’s moons, too.
Astronomers Without Borders are sponsoring a special Saturn Watch event April 11-16. See their website for more information about “Saturn Watch” and activity suggestions.
Here are more Saturn resources.
There are also several other fun observing events for Global Astronomy Month:
On April 9 the Global Star Party will unfold as darkness sweeps around the Earth. This is the night to set up your telescopes and share the wonders of the sky with others.
From April 10 to 16 it’s Lunar Week, to turn your gaze turns toward Earth’s natural satellite, and take a close-up look the Moon’s craters and “seas”.
April 12th is Yuri’s Night — and a very special one too, as it is the 50th anniversary of the first human in space.
The month closes with the Lyrid Meteor shower. On April 21/22 get comfortable in something warm and spend
the night scanning the sky for meteors caused by debris left behind by Comet Thatcher.
You can hear a podcast about Dark Skies Month on the April 5th 365 Days of Astronomy podcast.