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Our Best Ever Look at Pan, Saturn’s Little “UFO”

Images of the shepherd moon Pan captured by Cassini on March 7, 2017. (Credit: NASA/JPL-Caltech/SSI. Animation by Jason Major.)

Behold the almighty Pan! Thanks to Cassini’s ring-grazing orbits we’ve just received the highest-resolution images ever of Pan—which, at only about 17 miles (27 km) across admittedly isn’t very “almighty” but its flying saucer-like shape is really quite fascinating!

The raw images above were acquired by Cassini on March 7, 2017 and received on Earth on March 8. I assembled them into an animation to show some of the 3D shape of the little shepherd moon, which orbits Saturn inside the 200 mile wide Encke Gap in the A ring.

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Juno Will Not Enter Tighter Orbits Around Jupiter, Team Decides

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NASA’s Juno spacecraft will remain in 53-day-long orbits of Jupiter rather than rocket down to smaller 14-day orbits, despite the mission’s original plan to do so. Announced today, Feb. 17, this decision comes after evaluation of issues with helium valves that prevented orbital reduction burns in October and December of 2016.

“During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The bottom line is a burn represented a risk to completion of Juno’s science objectives.”

Even though Juno will remain in wider orbits its scientific objectives and capability to achieve them shouldn’t be affected—if anything, it will get a chance to explore more of Jupiter’s magnetic environment while reducing the time it spends in some of the more damaging regions of Jupiter’s radiation belts.

The solar-powered Juno spacecraft launched aboard a ULA Atlas V 551 rocket from Cape Canaveral on Aug. 5, 2011. After nearly five years and 1.7 billion miles of travel Juno arrived in orbit at Jupiter on July 4, 2016.

Read the full story here: NASA’s Juno Mission to Remain in Current Orbit at Jupiter

NASA’s Surprising Discoveries About Three Near-Earth Asteroids

The orbits of newly-discovered near-Earth asteroids 2013 UQ4, 2013 US10 and 2013 UP8 (NASA/JPL-Caltech)

The orbits of newly-discovered near-Earth asteroids 2013 UQ4, 2013 US10 and 2013 UP8 (NASA/JPL-Caltech)

Every few days or so I like to check the “Close Approaches” page of JPL’s Near-Earth Object Program, just to see what sorts of cosmic objects are whizzing by our planet; how big they are, when they’ll come, and how far they’ll (hopefully!) miss us by. Most of them are relatively small asteroids several dozen meters in width, passing us at a few tens of lunar distances (avg. distance to the Moon is about 370,000 km/235,000 miles or so.) Every now and then, though, something passes us by closely, coming within a handful of lunar distances — or even closer than the Moon itself. These events spark my interest as they remind us that there’s a lot of bits of solar system out there, and sometimes (while we’re busy doing other things) the bigger pieces get unnervingly close.

Yesterday JPL’s NEO specialists Don Yeomans and Paul Chodas posted an article about some “surprising discoveries” of three recently-found asteroids — all of which are of considerable size (two ~19 km/12 miles wide and one 2 km) and the third of which passes by closely enough to be considered “potentially hazardous” (as opposed to merely “near Earth”). Curious? Read on…
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Will Worlds Collide?

According to a June 10 article in New Scientist, studies on the variable nature of planetary orbits have shown some valid possibilities of collisions in the future. (The very distant future, luckily for us.)

Due to the nature of Jupiter’s massive gravitational pull on the inner planets, especially Mercury, their orbits are susceptible to incredible variances over time and thousands of different scenarios have been plotted via computer models. In some of these scenarios, Earth switches places with Venus and in some of those instances the two meet face-to-face in a fatal rendezvous. In other instances, Mars is the one to call on Earth, and in yet others some of the inner planets are thrown out of the solar system entirely.

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…Mars could hit Earth directly, be thrown out of the solar system, or come so close that Earth’s gravity would tear it into pieces which would rain down on our heads.

Don’t cancel your vacation plans or max out your credit cards just yet though….these catastrophic events are still just computer-generated theories, and all take place millions – even billions – of years in the future, if at all. We’ll be long gone by then, either as a species entirely or else living amongst the stars, or who knows where else.

But….that’s another hypothetical story altogether.

Original story: www.newscientist.com. Animation: J Vidal-Madjar/NASA/IMCCE-CNRS

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