Our Solar System Can Still Surprise Us!
Astronomers this week announced two exciting discoveries that demonstrate how much we still have to learn about our own solar system.
Published March 30, 2014
This has been a fun week in unusual news about our neck of the galaxy! Astronomers announced not one but two discoveries: a new object at the distant edge of our solar system and beautiful, never-before-seen rings on an asteroid that orbits between Saturn and Uranus.
The far-flung new object has been dubbed 2012 VP113 for now and is located in the Oort Cloud, a hypothesized layer of icy objects orbiting our sun way out beyond Neptune. At the most remote point in its orbit, VP113 is 70 billion kilometers (44 billion miles) away from the sun.
"Our known solar system consists of the rocky planets like Earth, which are close to the sun; the gas giant planets, which are further out; and the frozen objects of the Kuiper belt, which lie just beyond Neptune's orbit. Beyond this, there appears to be an edge to the solar system where only one object somewhat smaller than Pluto, Sedna, was previously known to inhabit for its entire orbit. But the newly found 2012 VP113 has an orbit that stays even beyond Sedna, making it the furthest known in the solar system," explains NASA.
The Oort Cloud is hypothesized to be a source of comets encasing the very outer limit of the solar system, beyond which our sun's gravitational influence loses out to others stars'. It has remained somewhat theoretical because the bodies comprising it, when in their normal orbits, are simply too far away to be seen with today's technology. VP113 was discovered near its perihelion (an object's closest approach to the sun) by astronomers Chad Trujillo and Scott Sheppard using the new Dark Energy Camera on the NOAO 4 meter telescope in Chile.
The existence of 2012 VP113 implies that there might be many more objects out there (potentially trillions!) and provides valuable fodder for continued research. "Not only that, but [VP113's and Sedna's] orbits hint at the possibility of another even larger object out there; perhaps even something as big as Earth! That's speculative, to be clear, but very interesting," comments Phil Plait at Bad Astronomy. He adds, "In some ways, this discovery was inevitable! But it's important nonetheless; we are peering into a region of the solar system that is ancient, but new to us. It's a window into the past, as well as a peek into an up-to-now invisible population of objects."
The ringed asteroid is called Chariklo, and nobody has ever seen anything like it. Every other known ringed object (Jupiter, Neptune, Uranus, and-of course-Saturn) is a planet. "The finding is a complete surprise to planetary scientists, who are yet unsure exactly how such rings could have formed," according to Adam Mann (@adamspacemann) at Wired.
The discovery and an assessment of the rings' possible causes are published in Nature by an international team of scientists. "Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies," explains the paper. "Their presence also tells us about the origin and evolution of the body they encircle."
Even as physicists are reporting the staggering, game-changing find of gravitational waves* from the Cosmic Microwave Background, it's exciting to think that our own cosmic corner also holds yet-unknown marvels. As Plait summarizes keenly, "We have an amazing grasp of how [the solar system] formed, evolved, and became the bustling place we see today. But there is still much to learn, and I can guarantee two things: We will learn more, and we’ll find far more surprises as we do."
*If you haven't been following that story, awesome! Here's a nice place to start.
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