Gaps in Saturn's Rings

By Fraser Cain - December 14, 2005 04:50 AM UTC | Planetary Science
In this Cassini image, Saturn's rings cast dark shadows across the face of the giant planet. The three bright arcs in the image are the three well-known gaps in Saturn's rings: the Cassini Division, the Encke Gap and the Keeler Gap. Cassini took this image on October 29, 2005 when it was 446,000 kilometers (277,000 miles) from Saturn.
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Hayabusa's Return Probably Delayed

By Fraser Cain - December 14, 2005 04:30 AM UTC | Missions
JAXA engineers are working hard to recover their ailing Hayabusa spacecraft. The spacecraft has been out of contact since December 9th, after it turned suddenly from a fuel leak. Hayabusa was supposed to return to Earth in June 2007, but JAXA is concerned that it won't have enough fuel to make this date, so they'll probably push the return back to 2010. Unfortunately, they have no way of knowing if Hayabusa actually retrieved a sample from Itokawa during its close encounter.
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Massive Gas Halos Surround Most Galaxies

By Fraser Cain - December 14, 2005 04:15 AM UTC | Extragalactic
ESA's XMM-Newton observatory has turned up hot gaseous halos around several spiral galaxies. These ghostly veils have been seen surrounding "starburst galaxies", which are going through a tremendous amount of star formation - but not around the more common kinds of galaxies. Unlike a starburst galaxies, which concentrates their halos, regular galaxies will have simmering star formation stretching across them entirely. These halos can contain up to 10 million solar masses of gas.
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Buffy the Kuiper Belt Object

By Fraser Cain - December 14, 2005 03:31 AM UTC | Planetary Science
An international team of astronomers have discovered a new large object in the Kuiper Belt; a region of the Solar System beyond the orbit of Neptune. The object's official designation is 2004 XR 190, but the discoverers are calling it "Buffy" for now. Buffy is approximately half the size of Pluto, and orbits the Sun roughly double the distance of Neptune. Although there are larger objects in the Kuiper Belt, Buffy has one of the most unusual orbits: 47-degrees off the plane of the ecliptic, where the other planets orbit.
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Strange Bulge in Saturn's Rings

By Fraser Cain - December 13, 2005 05:21 AM UTC | Planetary Science
NASA's Cassini spacecraft took this surprising photograph of Saturn's rings precisely edge-on. What's unusual is the strange bulge right at the edge of the rings. It's possible this bulge is created by a kilometer-sized chunk of material that's disrupting the ring material with its gravity. It could also be an effect of viewing the rings perfectly edge-on; normally faint material becomes visible when viewed at this angle.
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Plasma Engine Could Open Up Space Exploration

By Fraser Cain - December 13, 2005 05:08 AM UTC | Space Exploration
The European Space Agency is developing a new thruster based on the same physics that power the northern and southern auroras. This new plasma thruster could eventually deliver more power than the efficient ion engines which have been installed on several spacecraft. ESA engineers calculate that a plasma engine could deliver several times more thrust from a similar sized ion engine, but still be as fuel efficient.
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Spitzer Finds More than 100 New Star Clusters

By Fraser Cain - December 13, 2005 04:58 AM UTC | Stars
NASA's Spitzer Space Telescope has found more than 100 new star clusters hidden within the dusty areas of our own Milky Way. The powerful infrared observatory can see through the dark dust that normally obscures our view of this region of the galaxy. The team of astronomers that made the discovery found that there are twice as many clusters in the southern galactic plane (visible from the southern skies) as there are from the northern galactic plane. This may offer hints about the location of the Milky Way's spiral arms.
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Sirius' White Dwarf Companion Weighed by Hubble

By Fraser Cain - December 13, 2005 04:50 AM UTC | Stars
The brightest star in the nighttime sky is Sirius, aka the Dog Star. But did you know it has a white dwarf companion called Sirius B? Unfortunately, the light from this burned out star is washed out by Sirius' brilliant glow. Astronomers have been able to use the Hubble Space Telescope's sensitive instruments to isolate the light from Sirius B and measure its mass by how its gravity bends light emitted from the star. Even though it's only 12,000 kilometers (7,500 miles) across, Sirius B has 98% of the mass of our Sun.
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Thousands of Auroras on Mars

By Fraser Cain - December 13, 2005 04:39 AM UTC | Planetary Science
On Earth we have the Northern and Southern Lights, and there's a similar phenomenon on Mars too. But instead of sticking to the planet's poles, these faint auroras can show up anywhere on the planet; wherever there are patches of strong magnetic fields. Over the past six years, NASA's Mars Global Surveyor has turned up 13,000 aurora events on the Red Planet, and mapped their locations. These mini magnetic fields can potentially protect the planet's surface from the Sun's solar wind.
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What's Up This Week - December 12 - December 18, 2005

By Fraser Cain - December 12, 2005 08:42 AM UTC | Observing
Greetings, fellow SkyWatchers! It's "mid-time of night and the stars in their orbits shone pale through the light of the brighter cold Moon." But, be sure to take the time to "gaze for awhile on her cold smile"! There will be a brief opportunity this week to hide from that light to catch the Geminid meteor shower, as well as plenty of time to check out bright planets, stars and clusters. So turn your eyes to the skies, because...

Here's what's up!
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Detailed Dark Matter Maps

By Fraser Cain - December 12, 2005 01:30 AM UTC | Cosmology
Even through scientists have no idea what dark matter really is, they're able to see its effect on regular matter, and use this data to build a map of where it's clustered. Astronomers have used the Hubble Space Telescope to map the dark matter in two very young galaxy clusters. Their observations lend evidence to the theory that galaxies form at the densest regions of dark matter.
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Dione and Rhea in the Same Frame

By Fraser Cain - December 12, 2005 01:15 AM UTC | Planetary Science
Two of Saturn's moons, Rhea and Dione posed for Cassini in this photograph. The lower moon is Dione, which has been much more geologically active in the past than Rhea. Dione has a smoother surface and linear depressions, while Rhea looks quite pummeled by impacts, like our own Moon. When Cassini took this image, Rhea was 1.8 million kilometers (1.1 million miles) away, and Dione was 1.2 million kilometers (800,000 miles) away.
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Northern Lights on the Move

By Fraser Cain - December 12, 2005 01:00 AM UTC | Planetary Science
For more than 400 years, the Earth's magnetic North pole was in a roughly stable position, but now it's on the move, having drifted nearly 1,100 km (680 miles) in the last century. At this rate, it'll move out of Canada, and into Siberia in the next 50 years. If that happens, Alaska and Northern Canada may lose the beautiful Northern Lights, which are caused by the interaction of the magnetic pole and the solar wind. It could be that this is a normal oscillation of the magnetic pole, or it might be that the Earth's magnetic poles are getting ready to flip.
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Hayabusa Probably Didn't Get a Sample After All

By Fraser Cain - December 09, 2005 06:27 AM UTC | Planetary Science
The Japanese Hayabusa spacecraft has moved approximately 550 km (340 miles) away from Asteroid Itokawa, beginning the journey back to Earth. Unfortunately, it appears that the spacecraft probably failed to pick up a sample from the asteroid. JAXA officials now think that a metal bullet designed to blast material off of Itokawa's surface probably failed to fire. Hayabusa is severely damaged, and will attempt to make the return journey to Earth, but managers aren't optimistic about its chances.
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Women Wrap Up 60 Days of Simulated Spaceflight

By Fraser Cain - December 09, 2005 06:19 AM UTC | Space Exploration
Volunteers with the Women International Space Simulation for Exploration (WISE) campaign have wrapped up 60 days of bedrest, simulating the effects of weightlessness on the human body. The 24 women spent two months in medical beds which were slightly tilted head down. The data collected during the study will help prepare astronauts for long-duration spaceflight, but it'll also help researchers working on medical problems here on Earth too.
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Hopping Microrobots

By Fraser Cain - December 09, 2005 06:11 AM UTC | Space Exploration
The NASA Institute for Advanced Concepts has recently awarded a Phase II grant for a unique robot design that could hop across the surface of Mars. An array of these tiny robots could be deployed on Mars, coordinating with one another like a swarm of insects. Dr. Penelope Boston speaks to Astrobiology Magazine about the research and future potential for this direction of robotic exploration.
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Year in Space 2006 Giveaway!

By Fraser Cain - December 08, 2005 08:04 AM UTC | Site News
It's giveaway time again. The folks at Year in Space have agreed to award a free copy of the Year in Space 2006 calendar to one lucky Universe Today reader. As usual, send an email to [email protected] with the subject line "Year in Space 2006 Giveaway" before 8pm PST on Sunday, December 11. I'll pick one email randomly as the winner. If you haven't already, check out the calendar here. I'll only keep these emails for a few days and then delete them all, so they won't be used for anything else.

Good luck!

Fraser Cain
Publisher, Universe Today
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Book Review: Miss Leavitt's Stars

By Mark Mortimer - December 08, 2005 07:59 AM UTC | Stars
Press the correct buttons and the ATM spits out the cash you need for the weekend's jaunt. Lying behind the machine's panel, cables connect the ATM to computers that process millions of such transactions every second. Before this nano-age, people kept track of numbers using paper, pencil and an unfailing eye that looked at one item then the next. These human computers supported financiers and as George Johnson tells in his book, Miss Leavitt's Stars, they were also the backbone of early 20th century astronomy.
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Saturn's Graceful Crescent

By Fraser Cain - December 08, 2005 04:07 AM UTC | Planetary Science
This beautiful photograph of Saturn was taken when Cassini was lined up directly with the planet's rings. The black line near the top of the photograph are the rings. It's possible to see the intricate cloud patterns across the planet's surface, especially right at the terminator, which separates day from night. Cassini took this image on October 31, 2005 when it was 1.2 million kilometers (800,000 miles) from Saturn.
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