Saturn's rings contain soaring towers of ice →
Here’s something you don’t see everyday—or even every 15 years for that matter. These towering structures of ice and rock on the edge of Saturn’s middle rings are an incredible and rarely-captured sight visible only during the planet’s equinox.
These structures rise as far as 1.6 miles out of the edge of Saturn’s B ring, which has an average thickness of about 30 feet, and run for more than 750 miles. They’re believed to be the remnants of kilometer-wide moonlets that have broken up and been sucked into the swirling vortex of the planet’s rings.
However, despite their size, these features are rarely seen. Only during Saturn’s equinox, which happens once every 15 Earth years, does sunlight shines directly at the edge of the rings allowing them to cast shadow. This image was captured in 2009 by the Cassini space probe. We’ll have to wait until 2024 to catch another glimpse.
The hallmark of a grand design galaxy is its well-formed spiral arms, but getting into this conformation takes time. When astronomers look at most galaxies as they appeared billions and billions of years ago, they look clumpy and irregular. A 10.7-billion-year-old entity, BX442 came into existence a mere 3-billion years after the Big Bang. That’s not a lot of time on a cosmic time scale, and yet BX442 looks surprisingly put together. So much so, in fact, that astronomers didn’t believe it at first, chalking their unusual observation up to the accidental alignment of two separate galaxies. But further investigations, conducted at the W.M. Keck Observatory in Hawaii, revealed BX442 to be the real thing.
So how does a galaxy that shouldn’t exist come to be? The researchers think the answer may have something to do with a companion dwarf galaxy looming near BX442 (in the image up top, it’s the separate circular cluster in the upper right). Simulations conducted by University of Arizona researcher Charlotte Christenson indicate that gravitation interactions between the two, which she says appear to be in the process of colliding, may have helped BX442 take shape.