This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Some natural phenomena need few words to explain why they're fascinating. Eclipses, transits, and phases in astronomy tend to fall into that category. Here's a stunning sequence of images captured by the Hubble Space Telescope's Wide Field Camera 3 showing the triple conjunction and transit of the large Jovian moons Europa, Callisto, and Io over some 42 minutes in January 2015.
A triple transit
Jupiter of course has a lot of moons, 67 confirmed ones in fact. Some of these smaller ones were in on the act too, they're just too small to notice easily. Here's a guide to the position of 2 others - Thebe and Amalthea.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Two more transiting moons...(NASA/ESA)
So in fact this was a quintuple conjunction event!
And finally, in animated form.
Subscribe to Support Independent Journalism
Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.
When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.
Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber
