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Discovery of ice geysers on Saturn's moon Enceladus.
It's only been a few months since the Discovery of ice geysers on Saturn's Moon Enceladus, and now this dynamic process is turning up all over the Solar System. Astronomers think they've found a similar phenomenon on one of the strangest places: welling up from the surface of Pluto's Moon Charon.
The Discovery was made using the Gemini Observatory's adaptive optics system from atop Mauna Kea in Hawaii. The telescope picked out large deposits of ammonia hydrates and water crystals spread out across the surface of the icy moon.
Scientists think that water mixing with ice deep underneath Charon's surface is causing this material to push up through the moon's ultra-cold surface. This action could be happening quickly, taking just a few hours or even days. Over time, this process could give Charon a new surface one millimetre thick every 100,000 years. Of course, if Charon has this process going on, something similar could be happening across the Kuiper Belt.
The discoverers believe there's a dynamic process going on here because Charon's surface doesn't appear to be "primordial ice"; ice that was created during the formation of the Solar System. Instead, it's much more crystalline in appearance, and must have formed recently.
The next step will be to examine other Kuiper belt objects, like Quaoar and Orcus - both are larger than 500 km (310 miles) across.
Of course, the best thing would be to send a spacecraft and see these bodies up close.
It's very convenient, then, that NASA's New Horizon spacecraft is on its way, and will make a flyby in about a decade.
Original Source: Gemini News Release
Saturn's Moon Iapetus Enjoys Eternal Youth
Saturn's Moon Iapetus is one of the stranger objects in our Solar System. Unlike other objects its size, Iapetus is walnut-shaped, with a clearly defined chain of mountains along its equator. How could it have formed billions of years ago with the rest of the Solar System, and yet still have its unique shape?
New NASA supported researchers have developed a computer model that seems to accurately explain the series of events that Iapetus went through to arrive at its current shape.
Billions of years ago, shortly after its formation, Iapetus spun quickly, taking just 5 hours to complete a rotation. This fast spin gave it the oblate walnut shape it has today. Over time, its rotation slowed down to about 16 hours. It also cooled down enough that its surface froze solid. It couldn't absorb the excess surface material. Instead, this rubble built up the chain of mountains around its equator. At this point, its formation completely halted in its tracks. The Moon now orbits at a relatively slow rate, turning only once every 80 days.
Scientists were able to confirm these predictions for Iapetus, using observations of its rocks containing short-lived isotopes aluminum-26 and iron-60. These decay at a rate that allowed scientists to carbon date the Moon at roughly 4.564 billion years old. About the same age as the Earth.
NASA's Cassini spacecraft is due to make another flyby of Iapetus on September 10, 2007, passing within only 1,000 km (621 miles) of its surface.
Original Source: NASA Jet Propulsion
NASA is Sending a Phoenix to Mars
Since the launch of the Mars Phoenix Lander is just around the corner, I thought I'd give you a quick explainer on the mission.
So, let's get into it. Meet NASA's Mars Phoenix Lander. Scheduled for launch on August 3rd, this mission will blast off from Cape Canaveral atop a Delta II rocket. It'll take almost 10 months to reach Mars, entering the atmosphere in May, 2008.
The spacecraft is equipped with a pulsed thrust system to slow its descent through the atmosphere. Its landing system is pared down to the bare essentials to maximize the amount of scientific equipment it can land with. It doesn't have an airbag system like the rovers, and instead will use parachutes and thrusters to land gently on the surface on its three landing legs.
Unlike the Mars rovers currently crawling around the surface of the Red Planet, Mars Phoenix Lander will be stationary. Once it touches down in the Martian polar regions, it'll live out the rest of its days searching from that position.
Its purpose is to determine if life ever arose on the surface of Mars, or even there's life there today. Although the surface of Mars is cold, dry, scoured by wind and dust, and blasted by radiation from the Sun and space, just underneath the topsoil, there could water ice and even life, protected from the harsh elements.
The Phoenix Lander will use its 2.3 metre (7.7 feet) folding arm to dig down into the Martian soil around its landing site. NASA's Mars Odyssey spacecraft revealed that there are large deposits of water ice just a few centimetres beneath the surface of Mars. The Phoenix Lander should be able to break through into this crust, and see if there's anything alive down there.
The robotic arm will lift the soil samples up onto the main spacecraft deck so that a suite of scientific instruments can examine it for evidence of life. One will heat the samples, and measure the kinds of gases given off. Another will analyze the Chemistry of the soil itself.
In addition to its search for evidence of past and present life, Mars Phoenix Lander will serve as a Martian weather station, following changes in the polar regions to help scientists predict weather patterns on the Red Planet.
Good luck Mars Phoenix Lander.
Original Source: NASA/JPL News Release
Astrosphere for July 17, 2007
Today's wonderful astrophoto is from RickJ. That's two in two days Rick; nice going. It's a snapshot of M81, tearing apart another galaxy, Holmberg IX
Beverly Spicer at EarthSkyBlogs writes about a really cool World Clock
It's the myth that just won't die. I've already written about this every single year for 4 years now. But nope, the rumour's going around again. Mars as big as the moon!
Charles Daney gives the science explainer on axions; hypothetical particles that could explain dark matter.
Here's a timeline of climate change events for the 21st century.
Apparently we've got a deadline. According to the New York Times, we've got to get a colony established on Mars within 46 years... or else.
Large Outer planets are Rare
One of the big surprises the universe had in store for extrasolar planet hunters is the number of enormous planets close into their parent stars - the hot Jupiters. Another surprise seems to be how few large planets are found in the outer reaches of a solar system.
The Discovery was announced by an international team of Astronomers who concluded a three-year survey of 54 young, nearby stars. These should be among the best candidates to have large, Jupiter-sized planets further than 5 astronomical units from their parent stars (1 astronomical unit is the distance from the Earth to the Sun).
They didn't find a single planet.
Using the European Southern Observatory's powerful telescopes, such as the 8.2-metre Very Large Telescope (VLT) in Chile, the team had the ability to find outer super Jupiter planets at distances of more than 10 astronomical units from their stars. They had the imaging capability to spot them, but none turned up.
This new data helps Astronomers constrain their calculations about where and how giant planets form in other solar systems. They can refine their models to better understand how our own giant planets might have formed.
Original Source: UA News Release
What's Up this Week: July 16 - July 22, 2007
Monday, July 16 - Today in 1850 at Harvard University, the first photograph of a star (other than the Sun) was made. The honors went to Vega! In 1994, an impact event was about to happen as nearly two dozen fragments of comet Shoemaker-Levy 9 were speeding their way to the surface of Jupiter. The result was spectacular, and the visible features left behind on the planet's atmosphere were the finest ever recorded. Why not take the time to look at Jupiter again tonight while it still holds good sky position? No matter where you observe from, this constantly changing planet offers a wealth of things to look at - be it the appearance of the Great Red Spot, or just the ever changing waltz of the Galilean moons. Tonight the Moon and Saturn will not only be close - but very close! Be sure to check IOTA information for a visible occultation event!
Now let's return again to the oblate and beautiful M19 and drop two fingerwidths south for another misshapen globular - M62.
At magnitude 6, this 22,500 light-year distant Class IV cluster can be spotted in binoculars, but comes to wonderful life in the telescope. First discovered by Messier in 1771, Herschel was the first to resolve it and report on its deformation. Because it is so near to the galactic center, tidal forces have "crushed" it - much like M19. You will note when studying in the telescope that its core is very off center. Unlike M19, M62 has at least 89 known variable stars - 85 more than its neighbor - and the dense core may have undergone collapse. A large number of X-ray binaries have also been discovered within its structure, perhaps caused by the close proximity of stellar members. Enjoy it tonight!
Tuesday, July 17 - Tonight the Moon has returned in a position to favor a bit of study. Start by checking IOTA information for a possible visible occultation of Regulus, and look for Saturn quite nearby as the slender crescent graces the early evening skies.
Although poor position makes study difficult during the first few lunar days, be sure to look for the ancient impact Vendelinus just slightly south of central. Spanning approximately 150 kilometers in diameter and with walls reaching up to 4400 meters in height, lava flow has long ago eradicated any interior features. Its old walls hold mute testimony to later impact events as you view crater Holden on the south shore and much larger Lame on the northeast edge and sharp Lohse northwest. Mark your challenge list!
If you're up to another challenge tonight, let's go hunting Herschel I.44, also known as NGC 6104. You'll find this 9.5 magnitude globular cluster around two fingerwidths northeast of Theta Ophiuchi and a little more than a degree due east of star 51 (RA 17 38 36.93 Dec -23 54 31.5).
Discovered by William Herschel in 1784 and often classed as "uncertain," today's powerful telescopes have placed this Halo object as a Class VIII and given it a rough distance from the galactic center of 8,800 light-years. Although neither William nor John could resolve this globular, and they listed it originally as a bright nebula, studies in 1977 revealed a nearby suspected planetary nebula named Peterson 1. Thirteen years later, further study revealed this to be a symbiotic star.
Symbiotic stars are a true rarity - not a singular star at all, but a binary system. A red giant dumps mass towards a White Dwarf in the form of an accretion disc. When this reaches critical mass, it then causes a thermonuclear explosion resulting in a planetary nebula. While no evidence exists that this phenomenon is physically located within metal-rich NGC 6401, just being able to see it in the same field makes this journey both unique and exciting!
Wednesday, July 18 - On this day 27 years ago, India launched its first satellite (Rohini 1), and 31 years ago in the United States Gemini 10 launched carrying John Young and Michael Collins to space. Tonight we'll launch our imaginations as we view the area around Mare Crisium and have a look at this month's lunar challenge - Macrobius. You'll find it just northwest of the Crisium shore...
Spanning 64 kilometers in diameter, this Class I impact crater drops to a depth of nearly 3600 meters - about the same as many of our earthly mines. Its central peak rises up 1100 meters, and may be visible as a small speck inside the crater's interior. Be sure to mark your lunar challenges and look for other features you may have missed before!
Since the moonlight will now begin to interfere with our globular cluster studies, let's waive them for a while as we take a look at some of the region's most beautiful stars. Tonight your goal is to locate Omicron Ophiuchi, about a fingerwidth northeast of Theta. At a distance of 360 light-years, this system is easily split by even small telescopes. The primary star is slightly dimmer than magnitude 5 and appears yellow to the eye. The secondary is near 7th magnitude and tends to be more orange in color. This wonderful star is part of many double star observing lists, so be sure to note it!
Thursday, July 19 - Today in 1846, Edward Pickering was born. Although his name is not well known, he became a pioneer in the field of spectroscopy. Pickering was the Harvard College Observatory Director from 1876 to 1919, and it was during his time there that photography and astronomy began to merge. Known as the Harvard Plate Collection, these archived beginnings still remain a valuable source of data.
With plenty of Moon to explore tonight, why don't we try locating an area where many lunar exploration missions made their mark? Binoculars will easily reveal the fully disclosed areas of Mare Serenitatis and Mare Tranquillitatis, and it is where these two vast lava plains converge that we will set our sights. Telescopically, you will see a bright "peninsula" westward of where the two conjoin which extends toward the east. Just off that look for bright and small crater Pliny. It is near this rather inconspicuous feature that the remains Ranger 6 lie forever preserved where it crashed on February 2, 1964.
Unfortunately, technical errors occurred and it was never able to transmit lunar pictures. Not so Ranger 8! On a very successful mission to the same relative area, this time we received 7137 "postcards from the Moon" in the last 23 minutes before hard landing. On the "softer" side, Surveyor 5 also touched down near this area safely after two days of malfunctions on September 10, 1967. Incredibly enough, the tiny Surveyor 5 endured temperatures of up to 283 degrees F, but was able to spectrographically analyze the area's soil... And by the way, it also managed to televise an incredible 18,006 frames of "home movies" from its distant lunar locale.
When you're finished, why not have a look at something that would make Edward Pickering proud? He enthusiastically encouraged amateur astronomers, and founded the American Association of Variable star Observers - so set your sights on RR Scorpius about two fingerwidths northeast of Eta and less than a fingerwidth southwest M62 (RA 16 56 37.84 Dec -30 34 48.2). This very red Mira type can reach as high as magnitude 5 and drop as low as 12 in about 280 days!
Friday, July 20 - Today was a busy day in astronomy history! In 1969, the world held its breath as the Apollo 11 lander touched down and Neil Armstrong and Edwin Aldrin became the first humans to touch the lunar surface. We celebrate our very humanity because even Armstrong was so moved that he messed up his lines! The famous words were meant to be "A small step for a man. A giant leap for mankind." That's nothing more than one small error for a man, and mankind's success continued on July 20, 1976 when Viking 1 landed on Mars - sending back the first images ever taken from that planet's surface.
Tonight let's celebrate 36 years of space exploration and walk on the Moon where the first man set foot. For SkyWatchers, the dark round area you see on the northeastern limb is Mare Crisium and the dark area below that is Mare Fecunditatis. Now look mid-way on the terminator for the dark area that is Mare Tranquillitatis. At its southwest edge, history was made.
In binoculars, trace along the terminator where the Caucasus Mountains stand - and then south for the Apennines and the Haemus Mountains. As you continue towards the center of the Moon, you will see where the shore of Mare Serenitatis curves east, and also the bright ring of Pliny. Continue south along the terminator until you spot the small, bright ring of Dionysius along the edge of Mare Tranquillitatis. Just to the southwest, you may be able to see the soft rings of Sabine and Ritter. It is near here where the base section of the Apollo 11 landing module - Eagle - lies forever enshrined in "magnificent desolation."
For telescope users, the time is now to power up! See if you can spot small craters Armstrong, Aldrin and Collins just east. Even if you cannot, the Apollo 11 landing area is about the same distance as Sabine and Ritter are wide to the east-southeast.
Even if you don't have the opportunity to see it tonight, take the time during the next couple of days to point it out to your children, grandchildren, or even just a friend... The Moon is a spectacular world and we've been there!
Saturday, July 21 - Today in 1961, Mercury 4 was launched, sending Gus Grissom into suborbital space on the second manned flight, and he returned safely in Liberty Bell 7.
Long before the Sun sets, look for the Moon to appear in the still-blue sky. As it darkens, watch for brilliant blue/white Spica to be around a fingerwidth north of the Moon. Have you ever wondered if there was any place on the lunar surface that hasn't seen the sunlight? Then let's go searching for one tonight...
Our first order of business will be to identify crater Albategnius. Directly in the center of the Moon is a dark floored area known as Sinus Medii. South of it will be two conspicuously large craters - Hipparchus to the north and ancient Albategnius to the south. Trace along the terminator toward the south until you have almost reached its point (cusp) and you will see a black oval. This normal looking crater with the brilliant west wall is equally ancient crater Curtius. Because of its high southern latitude, we shall never see the interior of this crater - and neither has the Sun! It is believed that the inner walls are quite steep and that Curtius' interior has never been illuminated since its formation billions of years ago. Because it has remained dark, we can speculate that there may be "lunar ice" pocketed inside its many cracks and rilles that date back to the Moon's formation!
Because our Moon has no atmosphere, the entire surface is exposed to the vacuum of space. When sunlit, the surface reaches up to 385 K, so any exposed "ice" would vaporize and be lost because the Moon's gravity cannot hold it. The only way for "ice" to exist would be in a permanently shadowed area. Near Curtius is the Moon's south pole, and the Clementine spacecraft's imaging showed around 15,000 square kilometers in which such conditions could exist. So where did this "ice" come from? The lunar surface never ceases to be pelted by meteorites - most of which contain water ice. As we know, many craters were formed by just such impacts. Once hidden from the sunlight, this "ice" could remain for millions of years!
Sunday, July 22 - Tonight instead of lunar exploration, we will note the work of Friedrich Bessel, who was born on this day in 1784. Bessel was a German Astronomer and mathematician whose functions, used in many areas of mathematical physics, still carry his name. But, you may put away your calculator, because Bessel was also the very first person to measure a star's parallax. In 1837, he chose 61 Cygni and the result was no more than a third of an arc second. His work ended a debate that had stretched back two millennia to Aristotle's time and the Greek's theories about the distances to the stars.
Although you'll need to use your finderscope with tonight's bright skies, you'll easily locate 61 between Deneb (Alpha) and Zeta on the eastern side. Look for a small trio of stars and choose the westernmost. Not only is it famous because of Bessel's work, but it is one of the most noteworthy of double stars for a small telescope. 61 Cygni is the fourth nearest star to Earth, with only Alpha Centauri, Sirius, and Epsilon Eridani closer. Just how close is it? Try right around 11 light-years.
Visually, the two components have a slightly orange tint, are less than a magnitude apart in brightness and have a nice separation of around 30" to the south-southeast. Back in 1792, Piazzi first noticed 61's abnormally large proper motion and dubbed it "The Flying Star." At that time, it was only separated by around 10" and the B star was to the northeast. It takes nearly 7 centuries for the pair to orbit each other, but there is another curiosity here. Orbiting the A star around every 4.8 years is an unseen body that is believed to be about 8 times larger than Jupiter. A star - or a planet? With a mass considerably smaller than any known star, chances are good that when you view 61 Cygni, you're looking toward a distant world!
European Columbus Module Preparated for Atlantis Mission
With the shuttles back to their regular flight schedule, NASA is working through the backlog of components they need to attach to the International Space Station. One of the important ones will be the Columbus space laboratory, developed by the European Space Agency.
Columbus was flown to Florida back in May, 2006, to get in line for its launch to the station. Earlier this year, it was removed from temporary storage, and engineers equipped it with experiment racks and orbital hardware. After a break over the summer, workers will continue preparing it for launch. If all goes well, it will blast into space atop the Space Shuttle Atlantis as early as December 6th, 2007.
The module was originally supposed to launch in 2002, but the Columbia disaster and the station construction delays pushed the schedule back 5 years.
Original Source: ESA News Release
Building an Engine that Can Throttle Down
Here on Earth, we've gotten used to the concept of a car's accelerator pedal. Put it down a little, and the car accelerates slowly. Put the "pedal to the metal" and you'll go faster. Imagine trying to park your car when you only have two choices: off and full speed. Developing a similar concept for a rocket is very difficult. Most rockets are designed to go at full blast, or nothing at all.
A variable acceleration rocket would tremendously useful for landing on the Moon. Instead of firing the landing rockets in short bursts, astronauts could throttle down for a nice smooth landing. But building an engine like this is harder than it sounds.
NASA researchers think they've got a prototype engine that should give the variable rate of acceleration astronauts are looking for. The newly developed Common Extensible Cryogenic Engine (CECE) is a variant on the RL10 engine that boosted the Surveyor robot landers to the Moon back in 1966-68. The RL10 is designed to only go full throttle, so adding the variable thrust was difficult.
The main problem is that changing the throttle affects how the whole engine functions. At low power, liquid Hydrogen can slow and vapourize in the coolant lines. This might cause the engine to stall. During one test, the experimenters discovered that the engine "chugged", vibrating 100 times a second. It turned out oxygen vapours were forming on the injector plate, inhibiting normal flow, causing the vibrations.
It's not ready for space yet, but CECE might eventually become part of the design of a future lunar lander. The astronauts returning to the Moon will be very appreciative.
Astrosphere for July 16, 2007
Another day, another astrosphere.
First, the picture. Here's another image of comet CV2006VZ13 taken by forum member RickJ. I hope you're enjoying the comet pictures. With 2006VZ13 making its way across the night sky, we'll get a chance to see more of it. Keep snapping!
Earth and Sky is reporting on a successful method for determining the age of stars in other galaxies.
Livescience has a skeptical look at new research that pet visits to the emergency room increase during full moons.
On Belt of Venus, you can see the difficult challenge of splitting Alpha Scorpii (Antares / GNT 1) in a telescope.
The London Free Press has the results from a survey that shows how Canadians are anticipating space tourism.
Sleek Spacesuit Designed
Current spacesuit designs are bulky and cumbersome to wear. That's because they put an entire atmosphere around the astronaut, keeping them safe from the vacuum and temperature extremes of space. Instead of encasing an astronaut in a complete atmosphere, an alternative design using mechanical counter-pressure could give astronauts greater flexibility working in the vacuum of space.
Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT has designed a new spacesuit prototype that looks more like a superhero costume than a bulky NASA spacesuit. It works through the process of mechanical counter-pressure. Instead of an atmosphere to put pressure on the outside of a human body, it uses tight layers of fabric to give skin the pressure it needs.
Current spacesuit designs can weigh up to 136 kg (300 pounds), and are so restrictive to movement, that astronauts will spend the majority of their energy just working against the suit to bend it. A fabric-based design would be much more flexible and give astronauts a freedom of movement. Another advantage is safety. Even the slightest tear on a spacesuit will compromise its atmosphere, while a fabric suit can be easily patched up. To deal with the temperature extremes, astronauts could just put on and take off specially designed clothing.
The challenge in building a fabric-based spacesuit is to come up with a design that can exert close to one-third the pressure exerted by Earth's atmosphere. This is 30 KPa (kilopascals). The current prototype suit only provides 20 KPa consistently, but new models have gotten up to 25 to 30 Kpa. The best solution might end up being a hybrid, with the head and torso covered with a traditional spacesuit, and the arms and legs covered only in fabric.
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