Courtesy NASA/JPL/Space Science InstituteThe Cassini spacecraft made a recent approach to Saturn's moon Enceladus a couple days ago and captured some remarkable images of the icy plumes of water and organic compounds spraying into space from the moon's south pole. Kind of like a trip to Yellowstone without the crowds. The spacecraft also passed by two other moons, Janus and Dione.
Some unusual features of Enceladus are the tiger stripes that scour the moon's surface near its southern polar region. These markings appear to be the result of tectonic forces at work beneath the moon's ice-water shell. The geysers were first observed back in 2005. During Cassini's recent flybys the spacecraft took a taste of the jet sprays, analyzing their composition with special instrumentation.
"Aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth's oceans.“ - Dr Carolyn Porco, head of Cassini imaging team.
The orbit of Enceladus is distorted by Saturn's strong gravitation. This exerts tremendous pull on the moon creating heat and the subsequent generation of geologic activity that expresses itself on the surface with the tiger stripes and the geysers that emanate from them. The amount of water vapor leads scientists to think that an ocean exists just beneath Enceladus's icy surface.
Enceladus is Saturn's sixth largest moon and was discovered in 1789 by English astronomer William Herschel
Courtesy JAXA/HinodeLast week I posted a video of the Sun's gigantic coronal mass flare-ups that had the potential to disrupt our spacecraft and some of Earth's electromagnetic fields. Now, thanks to Robert Alexander at the University of Michigan in Ann Arbor, we can also hear how those solar storms sounded. Using raw data collected from NASA's Messenger spacecraft orbiting Mercury, and the Solar and Heliospheric Observatory (SOHO) about a million miles from Earth, Alexander converted the information into audio signals. Have a listen here (after a short ad, unfortunately). The sounds produced give the impression that the Sun is both very alien in nature, and extremely upset with us. Now we have to figure out what we did wrong?
Courtesy NASAThis is a perfect Buzz Burst post because it is about a big burst of solar activity that took place on our Sun just yesterday. Two giant coronal mass ejections (CME) occurred on our local star on March 6. The initial burst is heading our way at a speed of 1300 miles per second, and is expected to reach Earth sometime early tomorrow around 1:25 AM EST. This is the kind of high-energy solar activity that can mess up our communications, electrical fields, and spacecraft. The second CME of the solar cycle, shown in this amazing NASA video recorded by the Solar Dynamics Observatory (SDO), is shooting towards us at 1100 miles per second. Look for the spectacular images of the second flare's humongous shockwave moving across the entire face of the Sun at about a million miles per hour(!).
Courtesy alvherre at FlickrAcclaimed astrophysicist and author, Stephen Hawking, the former Lucasian Professor of Mathematics at the University of Cambridge - a position once held by Sir Isaac Newton - turns 70 years old today. Stricken with Amyotrophic lateral sclerosis (aka ALS or Lou Gehrig's disease), Hawking has defied doctors by living well-past their predicted "few years" when he was first diagnosed with the disease in 1963. A celebration in Britain took place today but Hawking was ill and couldn't attend the celebration. A recorded speech by Hawking was presented instead. Despite his debilitating disorder, Professor Hawking has managed to raise a family and through the use of computers to write several best-selling books, including A Brief History of Time. Here's an interview with Hawking's biographer, Kitty Ferguson. In Great Britain, ALS is known as motor neuron disease.
Courtesy NASAVoyager 1, an unmanned NASA space probe is nearing the outer edge of our solar system and will soon enter the vast, unknown region known as interstellar space. The crossover will remove the spacecraft from the influence of solar winds (from our Sun), into a relatively empty expanse of cold space influenced mostly by countering pressures created by supernovae, collapsed stars that died in immense catastrophic explosions. Voyager 1's primary mission, when it was launched 34 years ago on September 5, 1977, was to visit and photograph the giant gas planets in our solar system. It accomplished that goal and sent back spectacular images of the planets Jupiter, Saturn, Uranus, and Neptune. Right now Voyager 1 is about 11 billion miles from the sun, its cameras switched off, and poised for the next stage of its journey. The edge of the heliosphere is estimated to be somewhere between 10-14 billion miles from the Sun, so the probe could crossover anytime soon. NASA's Voyager program included two probes sent out with data gathering instruments and cultural souvenirs from the inhabitants of planet Earth, just in case they somehow got intercepted by some extraterrestrial lifeforms. Voyager 2, although launched two weeks before , trails some 2 billion miles behind Voyager 1, and will cross the boundary after its twin. You can read (and hear) more about it at the NPR website.
Courtesy NASA, ESA, and the Hubble Heritage Team (STScI/AURA)Hey look! Somebody made a snow angel in outer space! How appropriate and wonderful it should occur during this festive holiday season. This remarkable image was captured by the Hubble Telescope, and actually shows a star-making region of our Milky Way galaxy some 2000 light-years away in the direction of the constellation Cygnus. It’s a nebula (known as Sharples 2-106) that contains massive clouds of gas spreading across several light-years of space. The imagined perception of images (religious or otherwise) in nature or in ordinary, everyday objects isn’t something new. The Ancient Greeks called it simulacra and there’s even a scientific explanation for the phenomena . Still, it’s a pretty dang cool-looking celestial image, apropos for the season, and another item to add to the list.
Courtesy NASA/JPL-Caltech/T. PyleNASA announced this week the discovery of two Earth-sized planets orbiting a star 1000 light-years away in the constellation Lyra. The star system, called Kepler 20, is orbited by five planets. The two planets of interest, named Kepler-20e and Kepler-20f, are the first exoplanets their size to be discovered around another star resembling our own.
Francois Fressin, the lead author of the study which appears in the journal Nature, said the Kepler mission's main goal is to discover Earth-sized planets located in the habitable zone of other star systems. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them,” Fressin said.
Kepler 20e is slightly smaller than Venus, while Kepler-20f is slightly larger than Earth. The exoplanets' host star is smaller than the Sun and a bit cooler in temperature, however, the orbits of Kepler-20e and 20f are closer to their star than Mercury is to our sun, which makes them far too hot to support liquid water and too inhospitable to support life.
But the discovery is a big step in the three-and-a-half year Kepler mission, which uses ground-based telescopes and space telescopes to search out possible planet candidates.
This cool timelapse of Comet Lovejoy rising in the morning skies over Western Australia was created by Colin Legg. The comet's dust tail and secondary plasma tail can be seen rising out of the treetops in the lower right of the frame. You can see more of Legg's meteorological videos on his Vimeo link below.
Courtesy NASA/Carla CioffiAs a brand new year approaches, It's the time for making year-end lists, so here's Space.com's contribution for 2011. Russia's TMA-03M Soyuz spacecraft (pictured at right) blasted off just today - December 21 - with three astronauts aboard and headed for the International Space Station. It wasn't included in this year's list. Cool photo nonetheless.