NASA Probe Gets Close Views of Large Saturn Hurricane
NASA’s Cassini spacecraft has provided scientists the first close-up, visible-light views of a behemoth hurricane swirling around Saturn’s north pole.
In high-resolution pictures and video, scientists see the hurricane’s eye is about 1,250 miles (2,000 kilometers) wide, 20 times larger than the average hurricane eye on Earth. Thin, bright clouds at the outer edge of the hurricane are traveling 330 mph(150 meters per second). The hurricane swirls inside a large, mysterious, six-sided weather pattern known as the hexagon.
“We did a double take when we saw this vortex because it looks so much like a hurricane on Earth,” said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena. “But there it is at Saturn, on a much larger scale, and it is somehow getting by on the small amounts of water vapor in Saturn’s hydrogen atmosphere.”
Scientists will be studying the hurricane to gain insight into hurricanes on Earth, which feed off warm ocean water. Although there is no body of water close to these clouds high in Saturn’s atmosphere, learning how these Saturnian storms use water vapor could tell scientists more about how terrestrial hurricanes are generated and sustained.
Both a terrestrial hurricane and Saturn’s north polar vortex have a central eye with no clouds or very low clouds. Other similar features include high clouds forming an eye wall, other high clouds spiraling around the eye, and a counter-clockwise spin in the northern hemisphere.
A major difference between the hurricanes is that the one on Saturn is much bigger than its counterparts on Earth and spins surprisingly fast. At Saturn, the wind in the eye wall blows more than four times faster than hurricane-force winds on Earth. Unlike terrestrial hurricanes, which tend to move, the Saturnian hurricane is locked onto the planet’s north pole. On Earth, hurricanes tend to drift northward because of the forces acting on the fast swirls of wind as the planet rotates. The one on Saturn does not drift and is already as far north as it can be.
“The polar hurricane has nowhere else to go, and that’s likely why it’s stuck at the pole,” said Kunio Sayanagi, a Cassini imaging team associate at Hampton University in Hampton, Va.
Scientists believe the massive storm has been churning for years. When Cassini arrived in the Saturn system in 2004, Saturn’s north pole was dark because the planet was in the middle of its north polar winter. During that time, the Cassini spacecraft’s composite infrared spectrometer and visual and infrared mapping spectrometer detected a great vortex, but a visible-light view had to wait for the passing of the equinox in August 2009. Only then did sunlight begin flooding Saturn’s northern hemisphere. The view required a change in the angle of Cassini’s orbits around Saturn so the spacecraft could see the poles.
“Such a stunning and mesmerizing view of the hurricane-like storm at the north pole is only possible because Cassini is on a sportier course, with orbits tilted to loop the spacecraft above and below Saturn’s equatorial plane,” said Scott Edgington, Cassini deputy project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “You cannot see the polar regions very well from an equatorial orbit. Observing the planet from different vantage points reveals more about the cloud layers that cover the entirety of the planet.”
Cassini changes its orbital inclination for such an observing campaign only once every few years. Because the spacecraft uses flybys of Saturn’s moon Titan to change the angle of its orbit, the inclined trajectories require attentive oversight from navigators. The path requires careful planning years in advance and sticking very precisely to the planned itinerary to ensure enough propellant is available for the spacecraft to reach future planned orbits and encounters.
Image credit: NASA/JPL-Caltech/SSI
How A New Family Tree of Space Rocks Could Better Protect Earth
In perhaps the neatest astronomical application of geneology yet, astronomers found 28 “hidden” families of asteroids that could eventually show them how some rocks get into orbits that skirt the Earth’s path in space.
From scanning millions of snapshots of asteroid heat signatures in the infrared, these groups popped out in an all-sky survey of asteroids undertaken by NASA’s orbiting Wide-Field Infrared Survey Explorer. This survey took place in the belt of asteroids between Mars and Jupiter, where most near-Earth objects (NEOs) come from.NEOs, to back up for a second, are asteroids and comets that approach Earth’s orbit from within 28 million miles (45 million kilometers). Sometimes, a gravitational push can send a previously unthreatening rock closer to the planet’s direction. The dinosaurs’ extinction roughly 65 million years ago, for example, is widely attributed to a massive rock collision on Earth.
Part of NASA’s job is to keep an eye out for potentially hazardous asteroids and consider approaches to lessen the threat.
There are about 600,000 known asteroids between Mars and Jupiter, and the survey looked at about 120,000 of them. Astronomers then attempted to group some of them into “families”, which are best determined by the mineral composition of an asteroid and how much light it reflects.
While it’s hard to measure reflectivity in visible light — a big, dark asteroid reflects a similar amount of light as a small shiny one — infrared observations are harder to fool. Bigger objects give off more heat.
This allowed astronomers to reclassify some previously studied asteroids (which were previously grouped by their orbits), and come up with 28 new families.
“This will help us trace the NEOs back to their sources and understand how some of them have migrated to orbits hazardous to the Earth,” stated Lindley Johnson, NASA’s program executive for the Near-Earth Object Observation Program.
The astronomers next hope to study these different families to figure out their parent bodies. Astronomers believe that many asteroids we see today broke off from something much larger, most likely through a collision at some point in the past.
While Earthlings will be most interested in how NEOs came from these larger bodies and threaten the planet today, astronomers are also interested in learning how the asteroid belt formed and why the rocks did not coalesce into a planet.
The prevailing theory today says that was due to influences from giant Jupiter’s strong gravity, which to this day pulls many incoming comets and asteroids into different orbits if they swing too close. (Just look at what happened to Shoemaker-Levy 9 in 1994, for example.)
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image 1: An artist’s conception of an asteroid collision, which leads to how “families” of these space rocks are made in the belt between Mars and Jupiter. credit: NASA/JPL-Caltechimage 2: Artist concept of the asteroid belt between Mars and Jupiter. credit: NASA
image 3: This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). credit: NASA/JPL-Caltech
Planetary Resources, the Planetary Society, and The Museum of Flight are partnering in the crowd sourcing of a “Space Telescope for Everyone.” And the perks are amazing and, frankly, cheap. $25 for a picture of yourself in space. $200 for the ability to photograph an astronomical object from an observatory in space.
I purchased package that gives time on the telescope to a classroom as well as curricula and other resources.
These are opportunities that not only didn’t exist until recently, they COULDN’T EXIST! Without the cultural concept of crowd funding and the technological progress in optics and computing, this would literally be impossible.
In fact, it still seems a little bit impossible to me…but these people are very very serious…and the cooles thing is that they’re serious about making the world a better place, educating future scientists, and building an optimistic, abundant future. This is a pretty inspiring place to be…and a pretty inspiring time to exist.
Galaxy Coast
— Bill Shupp // FlickrTaken near Bixby Bridge north of Big Sur, CA, this is a 12 shot vertical panorama taken around 4 am this past Monday, when the Milky Way was pretty high in the sky. The glow near the horizon is a lighthouse just around the bend.
All shots are 20 seconds, except the bottom one, which is 3 minutes
If Earth Had Rings
First off, they would be really pretty to look at. They would also dominate the sky in both night and day at exactly the same place as they would never rise nor set. And at night you would see the Earth’s shadow swing across the rings, like in the 4th photo here.
However, life would be very different on Earth if this were the case. Nocturnal animals would have a hard time being nocturnal, as the light reflecting from the rings would illuminate the night.
Because we are closer to the Sun than Saturn is, the rings would be more rocky than ice, making them less bright but still pretty bright. In fact, you would see far less stars at night (living anywhere other than the equator or the arctic circle) because of the light pollution and not to mention ruin most meteor showers because of that.
During the day the rings would block sunlight in certain regions of the planet creating wild weather cycles and effecting plant life as well. So basically, they would be definitely pretty to look at but they would also make a whole lot of things screwy.
Illustrations by Ron Miller // io9
— Click the photos for captions
Brace yourself for another asteroid flyby
To quote science reporter Deborah Netburn:
It’s 1.7 miles long. Its surface is covered in a sticky black substance similar to the gunk at the bottom of a barbecue. If it impacted Earth it would probably result in global extinction. Good thing it is just making a flyby.
At approximately 1:59 p.m. PDT May 31, Asteroid 1998 QE2 will make a close (by galactic standards) pass by our home planet. Coming within just 3.6 million miles of Earth, the asteroid will be so close that many of its features will be visible on radar.
For more details on the asteroid, including its possible origin, at Science Now.
Photo: NASA / JPL / Caltech
Watch live as astronaut Chris Hadfield descends back to Earth after five months in space
This evening, Chris Hadfield will begin his decent to Earth after spending five months in space. Hadfield arrived at the International Space Station on December 21, 2012 and was the first Canadian commander of the ISS after the previous crew returned to Earth.13 minutes from touch down. Posted: 10:19.pm.
Accompanied by this, just perfect.
With deference to the genius of David Bowie, here’s Space Oddity, recorded on Station. A last glimpse of the World.
Huge thanks in the making of the video to the talented trio of Emm Gryner, Joe Corcoran and Andrew Tidby, plus Evan Hadfield and all at the CSA.
I’m going to miss you in space Col. Hadfield.
The Most Astounding Fact - Neil deGrasse Tyson (by Max Schlickenmeyer)
