Posted on by Nancy Atkinson

Lost in Space: Tool Bag Overboard, Spider Missing

Last weeks web... a tangled mess (NASA)


A tool bag floated away in space as spacewalking astronauts worked outside the International Space Station Tuesday. Heide Stefanyshyn-Piper had a grease gun explode inside her tool bag, getting the dark gray goop all over a camera, the inside of the bag, and her gloves. While she was trying to clean it up, the whole bag floated away. “Oh, great,” Piper said. It was one of the largest items ever to be lost by a spacewalker. Lost were two grease guns, needed to clean and lube the jammed Solar Alpha Rotary Joint for the space station’s solar arrays. Flight director Ginger Kerrick said the bag and also an errant screw that also floated past that spacewalkers posed no hazards to the ISS or shuttle. By late Tuesday, the bag was already well away from the complex, about 2.5 miles (4 km) in front of the shuttle-station complex. The rest of the spacewalk went well, as Piper and her partner Stephen Bowen shared tools and accomplished all the planned objectives. Mission planners are studying options for replacing, or doing without, two grease guns lost.

Also lost is one of two spiders on board a special experiment…


While one orb weaver spiders weaved away in an ususual unsymmetrical manner, one spider is MIA.
“We don’t believe that it’s escaped the overall payload enclosure,” said Kirk Shireman, NASA’s deputy station program manager. “I’m sure we’ll find him spinning a web sometime here in the next few days.”

“The web was more or less three-dimensional and it looked like it was all over the inside of the spider hab,” said NASA astronaut Sandra Magnus, the space station’s science officer. “We took some pictures of it.” And here’s an image:
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Painted lady butterfly larvae were also included as a separate part of the experiment.

Students will compare the space butterflies’ lifecycle and how the spiders weave webs and feed in weightlessness with similar spiders and butterflies on Earth.

Also inside the station, astronauts moved two 1,700-pound (770 kg) water recycling racks into the Destiny lab module, as well as combustion research gear, and a new toilet and crew sleep stations.

The water recycling gear, which will convert condensate and urine into pure water for drinking, food preparation, hygiene and oxygen generation, is crucial for NASA’s plans to boost the station’s crew size to six next year. The astronauts hoped to hook up the two water processing racks today (Wednesday) and to begin pumping stored urine into the system Thursday.

Water samples will be returned to Earth aboard Endeavour for detailed chemical analysis. A full three months of testing is planned in orbit, with additional ground tests after the next shuttle visit in February, before any astronauts are allowed to drink the recycled water.

Sources: MSNBC, UPI

Posted on by Nancy Atkinson

NASA and Google Successfully Test Deep Space Internet

Interplanetary Internet concept.

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Communication with spacecraft is vital for NASA, and since the World Wide Web has enabled easy, reliable and quick contact for people around the world, the space agency decided to model a new deep space communication system on the internet. A month-long test of this “Interplanetary Internet” was successfully conducted by transmitting dozens of images to and from the EPOXI spacecraft, now about 20 million miles from Earth. The system uses software called Disruption-Tolerant Networking, or DTN created by a partnership between NASA and Google vice president Vint Cerf. “This is the first step in creating a totally new space communications capability, an interplanetary Internet,” said Adrian Hooke, team lead and manager of space-networking architecture, technology and standards at NASA Headquarters in Washington.

NASA’s current communication system, the Deep Space Network, has been around since the early days of space travel, and NASA is looking to upgrade and enhance their ability to communicate with spacecraft. The Interplanetary Internet must be robust to withstand delays, disruptions and disconnections in space. Glitches can happen when a spacecraft moves behind a planet, or when solar storms and long communication delays occur. The delay in sending or receiving data from Mars takes between three-and-a-half to 20 minutes at the speed of light. Therefore, the DTN sends information using a method that differs from the normal Internet’s Transmission-Control Protocol/Internet Protocol, or TCP/IP, communication suite, which Cerf also co-designed.

Unlike TCP/IP on Earth, the DTN does not assume a continuous end-to-end connection. In its design, if a destination path cannot be found, the data packets are not discarded. Instead, each network node keeps the information as long as necessary until it can communicate safely with another node. This store-and-forward method, similar to basketball players safely passing the ball to the player nearest the basket means information does not get lost when no immediate path to the destination exists. Eventually, the information is delivered to the end user. This is all done automatically.

Engineers began a month-long series of DTN demonstrations in October. Data were transmitted using NASA’s Deep Space Network in demonstrations occurring twice a week. Engineers use NASA’s EPOXI spacecraft as a Mars data-relay orbiter. EPOXI spacecraft is the bus from the Deep Impact mission that send an impactor to Comet Temple 1 in July of 2005, and it is now on a mission to encounter Comet Hartley 2 in two years. There are 10 nodes on this early interplanetary network. One is the EPOXI spacecraft itself and the other nine, which are on the ground at JPL, simulate Mars landers, orbiters and ground mission-operations centers.

This month-long experiment is the first in a series of planned demonstrations to qualify the technology for use on a variety of upcoming space missions. As Ian reported last month, the next round of testing will be done on the International Space Station next summer.

In the next few years, the Interplanetary Internet could enable many new types of space missions. Complex missions involving multiple landed, mobile and orbiting spacecraft will be far easier to support through the use of the Interplanetary Internet. It also could ensure reliable communications for astronauts on the surface of the moon.

Source: NASA

Posted on by Nancy Atkinson

New Telescope on the Lookout for Near Earth Asteroids, Comets

Pan-STARRS 1 prototype, part of the Panoramic Survey Telescope and Rapid Response System, Haleakala mountain, Maui. Photo / MIT Lincoln Laboratory

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A prototype telescope with an enhanced ability to find moving objects will soon be operational, and its mission will be to detect asteroids and comets that could someday pose a threat to Earth. The system is called Pan-STARRS (for Panoramic Survey Telescope and Rapid Response System) located on Haleakala mountain in Maui,Hawaii, and is the first of four telescopes that will be housed together in one dome. Pan-STARRS will feature the world’s largest and most advanced digital camera, providing more than a fivefold improvement in the ability to detect Near Earth Asteroids and comets. “This is a truly giant instrument,” said University of Hawaii astronomer John Tonry, who led the team developing the new 1.4-gigapixel camera. “We get an image that is 38,000 by 38,000 pixels in size, or about 200 times larger than you get in a high-end consumer digital camera.” The Pan-STARRS camera will cover an area of sky six times the width of the full moon and it can detect stars 10 million times fainter than those visible to the naked eye.

The Lincoln Laboratory at the Massachusetts Institute of Technology (MIT) developed charge-coupled device (CCD) technology is a key enabling technology for the telescope’s camera. In the mid-1990s, Lincoln Laboratory researchers developed the orthogonal-transfer charge-coupled device (OTCCD), a CCD that can shift its pixels to cancel the effects of random image motion. Many consumer digital cameras use a moving lens or chip mount to provide camera-motion compensation and thus reduce blur, but the OTCCD does this electronically at the pixel level and at much higher speeds.

The challenge presented by the Pan-STARRS camera is its exceptionally wide field of view. For wide fields of view, jitter in the stars begins to vary across the image, and an OTCCD with its single shift pattern for all the pixels begins to lose its effectiveness. The solution for Pan-STARRS, proposed by Tonry and developed in collaboration with Lincoln Laboratory, was to make an array of 60 small, separate OTCCDs on a single silicon chip. This architecture enabled independent shifts optimized for tracking the varied image motion across a wide scene.

“Not only was Lincoln the only place where the OTCCD had been demonstrated, but the added features that Pan-STARRS needed made the design much more complicated,” said Burke, who has been working on the Pan-STARRS project. “It is fair to say that Lincoln was, and is, uniquely equipped in chip design, wafer processing, packaging, and testing to deliver such technology.”

The primary mission of Pan-STARRS is to detect Earth-approaching asteroids and comets that could be dangerous to the planet. When the system becomes fully operational, the entire sky visible from Hawaii (about three-quarters of the total sky) will be photographed at least once a week, and all images will be entered into powerful computers at the Maui High Performance Computer Center. Scientists at the center will analyze the images for changes that could reveal a previously unknown asteroid. They will also combine data from several images to calculate the orbits of asteroids, looking for indications that an asteroid may be on a collision course with Earth.

Pan-STARRS will also be used to catalog 99 percent of stars in the northern hemisphere that have ever been observed by visible light, including stars from nearby galaxies. In addition, the Pan-STARRS survey of the whole sky will present astronomers with the opportunity to discover, and monitor, planets around other stars, as well as rare explosive objects in other galaxies.

Click here for more information about Pan-STARRS.

Source: MIT

Posted on by Astronomy Cast

Podcast: The Moon, Part 3: Return to the Moon

Altair Lander. Image credit: NASA

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It’s time for a third lunar chapter. We’ve talked about the physical characteristics of the Moon, and the exploration. Now we’re going to talk about the plans to return to the Moon. From the upcoming lunar reconnaissance orbiter to the plans to have humans set foot on the Moon again, for the first time in more than 50 years.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

The Moon, Part 3: Return to the Moon – Transcript and show notes.

Posted on by Astronomy Cast

Podcast: Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear

Artist impression of the Milky Way.

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This week we explore galactic spiral arms, seismic quakes on the Sun, and our picks for astronomy gear. If you’ve got a question for the Astronomy Cast team, please email it in to [email protected] and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear – Transcript and show notes.

Posted on by Nancy Atkinson

Black Holes Supply Lifeblood for Galaxies

Chandra X-ray image of M84 (NASA/CXC/MPE/A.Finoguenov et al.); Radio (NSF/NRAO/VLA/ESO/R.A.Laing et al); Optical (SDSS)

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Obviously, today is the day for news on black holes. While one group of astronomers studied the violent flares of energy sent out by black holes in the near infrared and submillimeter wavelengths, another group used the Chandra X-Ray Observatory to see how black holes can pump energy in a gentler and rhythmic fashion, rather than violently. These scientists say the powerful black holes at the center of massive galaxies act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation. “Just like our hearts periodically pump our circulatory systems to keep us alive, black holes give galaxies a vital warm component. They are a careful creation of nature, allowing a galaxy to maintain a fragile equilibrium,” said Alexis Finoguenov, of the Max-Planck Institute for Extraterrestrial Physics in Germany.

The scientists observed and simulated how the black hole at the center of elliptical galaxy M84 dependably sends bubbles of hot plasma into space, heating up interstellar space.

Here’s an animation of the regular pulses of bubbles.

This heat is believed to slow both the formation of new stars and the growth of the black hole itself, helping the galaxy remain stable. Interstellar gases only coalesce into new stars when the gas is cool enough. The heating is more efficient at the sites where it is most needed, the scientists say.

This finding helps to explain a decades-long paradox of the existence of large amounts of warm gas around certain galaxies, making them appear bright to the Chandra X-ray telescope.

“For decades astronomers were puzzled by the presence of the warm gas around these objects. The gas was expected to cool down and form a lot of stars” said Mateusz Ruszkowski, an assistant professor in the University of Michigan Department of Astronomy.

“Now, we see clear and direct evidence that the heating mechanism of black holes is persistent, producing enough heat to significantly suppress star formation. These plasma bubbles are caused by bursts of energy that happen one after another rather than occasionally, and the direct evidence for such periodic behavior is difficult to find.”

The bubbles form one inside another, for a sort of Russian doll effect that has not been seen before, Ruszkowski said. One of the bubbles of hot plasma appears to be bursting and its contents spilling out, further contributing to the heating of the interstellar gas.

“Disturbed gas in old galaxies is seen in many images that NASA’s Chandra observatory obtained, but seeing multiple events is a really impressive evidence for persistent black hole activity,” says Christine Jones, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

A paper on the research called “In-depth Chandra study of the AGN feedback in Virgo Elliptical Galaxy M84” has been published in Astrophysical Journal.

Source: University of Michigan

Posted on by Nancy Atkinson

Milky Way’s Black Hole Sending Out Flares

Left: Submillimetre and infrared view of the Galactic Centre Right: Flares from the disk of material surrounding the black hole Sagittarius A*. Credit: ESO/APEX/2MASS/A. Eckart et al. , ESO/L. Calçada

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Two different telescopes simultaneously observed violent flares from the supermassive black hole in the center of the Milky Way. The outbursts from this region, known as Sagittarius A*, reveal material being stretched like bread dough out as it orbits in the intense gravity close to the central black hole. Using ESO’s Very Large Telescope (VLT) and the Atacama Pathfinder Experiment (APEX) telescope, both in Chile, to study light from Sagittarius A* at near-infrared wavelengths and the longer submillimeter wavelengths, astronomers have for the first time concurrently caught a flare with these telescopes. “Observations like this, over a range of wavelengths, are really the only way to understand what’s going on close to the black hole,” says Andreas Eckart of the University of Cologne, who led the team.

Sagittarius A* is located at the centre of our own Milky Way Galaxy at a distance from Earth of about 26,000 light-years. It is a supermassive black hole with a mass of about four million times that of the Sun. Most, if not all, galaxies are thought to have a supermassive black hole in their center.

“Sagittarius A* is unique, because it is the nearest of these monster black holes, lying within our own galaxy,” explains team member Frederick K. Baganoff of the Massachusetts Institute of Technology (MIT) in Cambridge, USA. “Only for this one object can our current telescopes detect these relatively faint flares from material orbiting just outside the event horizon.”

The emission from Sagittarius A* is thought to come from gas thrown off by stars, which then orbits and falls into the black hole.

The VLT pointed their telescope at Sagittarius A* and saw it was active, and getting brighter by the minute. They contacted their colleagues at the APEX telescope, who were able to also catch the flares. Both telescopes are in the southern hemisphere, which provides the best vantage point for studying the Galactic Center.

Over the next six hours, the team detected violently variable infrared emission, with four major flares from Sagittarius A*. The submillimeter-wavelength results also showed flares, but, crucially, this occurred about one and a half hours after the infrared flares.

The researchers explain that this time delay is probably caused by the rapid expansion, at speeds of about 5 million km/h, of the clouds of gas that are emitting the flares. This expansion causes changes in the character of the emission over time, and hence the time delay between the infrared and submillimetre flares.

Although speeds of 5 million km/h may seem fast, this is only 0.5% of the speed of light. To escape from the very strong gravity so close to the black hole, the gas would have to be travelling at half the speed of light – 100 times faster than detected – and so the researchers believe that the gas cannot be streaming out in a jet. Instead, they suspect that a blob of gas orbiting close to the black hole is being stretched out, like dough in a mixing bowl, and this is causing the expansion.

The team hopes that future observations will help them discover more about this mysterious region at the center of our Galaxy.

Read the team’s paper here.

Source: ESO

Posted on by Tammy Plotner

Lepus

Lepus

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Created as one of Ptolemy’s original 48 constellations and positioned just south of the celestial equator, Lepus has endured the test of time to become one of the 88 modern constellation recognized by the IAU. Spanning 290 square degrees of sky, it ranks fifty-first in size and contains only 2 bright stars, yet has 8 stars in its major asterism. Within the confines of Lepus you will also find 20 stars with Bayer/Flamsteed designations. It is bordered by the constellations of Orion, Monoceros, Canis Major, Columba, Caelum and Eridanus. Lepus is visible to all observers at latitudes between +63° and ?90° and is best seen at culmination during the month of January.

In mythology, or perhaps more correctly story and legend, Lepus represents the hare at Orion the Hunter’s feet. It is believed the winged messenger god, Hermes honored the hare for its speed, giving it a place amongst the stars. It is also believed that Canis Major, Orion’s dog, forever pursues Lepus across the sky. The Egyptians saw this constellation as associated with Osiris and fertility… Of course, there is no more fertile creature than a rabbit!

Let’s start our binocular tour of Lepus with Alpha Leporis – the “a” symbol on our map. Its name is Arneb and it literally means “hare” in Arabic. Arneb is an older, dying star that may have already passed through a supergiant phase and is now contracting and heating up in the latter phases of stellar evolution, or perhaps is still expanding into the supergiant phase. With a mass of likely less than 10 times that of the Sun, it will likely end its life as a hot white dwarf, although if it is at the heavier end of its estimated mass it may end in a spectacular stellar explosion known as a supernova. Positioned about 1300 light years from Earth, Arneb may be dying… But it still has a few years of light left for you to enjoy!

Stay with binoculars and head south for Beta Leporis – the “B” symbol on our map. Beta’s proper name is Nihal – the “drinking camel”. Somewhat similar to our Sun, this unusual 159 light year distant dwarf star outshines Sol by 165 times. Why? Probably because it’s 16 times larger. Inside it has a rapidly evolving helium core and in less than a million years it will brighten as it begins to fuse its internal helium into carbon. Now take a look in a telescope. That’s right, Nihal is a binary star. About 2.5 seconds of arc away you’ll find a companion star that’s sometimes as bright as stellar magnitude 7 and sometimes as dim as 11. So what’s going on here? Chances are the companion star is an eclipsing double, much like an Algol-type. What’s more, the primary star – Nihal A – is also a bright X-ray source, which means it has strong stellar magnetic properties. According to research, it has a high content of yttrium and the rare earths praseodymium, neodymium, and samarium – chemicals that occurred because it began life just a little hotter than usual!

Now hop to Gamma Leporis – the “Y” shape on our chart. Gamma is a multiple star system which is about 29 light-years from Earth and consists of 2 or possibly 3 stars. What’s so cool about another multiple system? This one is on the move! Gamma is part of the Sirius Moving Group Of Stars. These stars are all about the same distance away and part of a larger collective of stars known as the Ursa Major Moving Group. Based upon its stellar characteristics and distance from Earth, Gamma Leporis, a main-sequence white-yellow dwarf star, is considered a high-priority target for NASA’s Terrestrial Planet Finder mission as well!

Point your binoculars or telescope at R Leporis – better known as “Hind’s Crimson Star”. Very few places in the sky will you find such ruby beauty! This well-known variable star is right on the border of Eridanus, but since the border doesn’t show on the sky, simply use bright Rigel to help you locate it. Named after famous British astronomer J.R. Hind, who observed it in 1845, you’ll find the most excellent carbon star varies from around magnitude 5 to 12 in about 427 to 432 days. In other words, you basically observe it from one year to the next! Hind’s Crimson star is the most beautiful when it is a minima, displaying an incredible smoky red color, which turns almost garnet as it brightens the following year. Enjoy this annual favorite!

Now keep those binoculars and telescopes handy as we drop a little less than four degrees south/southwest (a binocular field) of Beta and go for Messier 79 (RA 05:24.5 Dec -24:33). This 7th magnitude globular cluster was originally discovered by Pierre Mechain and later added to the Messier Catalog. Located about 40,000 light years from our solar system, the huge ball of stars spread across 118 light years of space an incorporates tens of thousands of distant suns. What’s unusual about it? Chances are, M79 is an import to our Milky Way Galaxy. From what we can tell through recent studies, this globular cluster may have actually belonged the the Canis Major dwarf galaxy at one time and became part of our galaxy through a galaxy collision! For double star fans, look another half degree southwest where you’ll see fifth magnitude ADS 3954 and its seventh magnitude companion. A nice same field bonus!

Sources: SEDS, Wikipedia
Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Leo Minor

Leo Minor

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Leo Minor is a very small and dim constellation which was created by Johannes Hevelius in 1687 and later recognized as one of the 88 modern constellations. While Leo Minor did not belong to any older star catalogs such as those drawn up by Ptolemy in the 2nd century AD, this set of stars became part of the Firmamentum Sobiescianum, a 56 sheet atlas created by master astronomer Hevelius in an attempt to update star catalogs using what (was then) considered modern equipment. Leo Minor was one of seven new constellations and endured to become officially recognized by the International Astronomical Union. It possesses no bright stars and has only 2 main stars in its asterism, yet there are 34 Bayer/Flamsteed designated stars within Leo Minor’s confines. It spans 232 square degrees of sky and is bordered by the constellations of Ursa Major, Lynx, Cancer and Leo. Leo Minor is visible to all observers at latitudes between +90° and ?45° and is best seen at culmination during the month of April.

Since Leo Minor, the “Little Lion” is consider a new constellation, it has no ancient mythology associated with it. As you may have noticed by looking at the chart, it curiously has no Alpha star. When it came to making charts, Hevelius was great – but he didn’t label stars. It wasn’t until the 19th-century when English astronomer Francis Baily had a go at Leo Minor that he assigned the stars with their Greek letters and he simply overlooked the Alpha designation! Leo Minor is just another example of how constellation names and figures can sometimes repeat themselves, like Ursa Major and Minor, Canis Major and Minor, Pegasus and Equuleus… Hydra and Hydrus. Half the challenge to this constellation is simply finding it!

Break out your binoculars and let’s have a look at Beta Leonis Minoris – the “B” shape on our map.. This is a very rapid binary star – not in terms of movement through space – but in orbit of its companion star. Believe it or not, the 6th magnitude companion completes a full orbit in less than 40 years. That’s just a little bit slower than Saturn takes to orbit our Sun and over twice as fast at it takes Neptune!

Now head east for 46 Beta Leonis Minoris. By all rights, this should have been the Alpha star and it’s the only Bayer/Flamsteed numbered stellar designation to have a proper name – Praecipua. As stars go? Well, Praecipua is actually pretty ordinary. Just another orange giant star hanging out in space around 98 light years from Earth. It is happily radiating away about 32 times brighter than our Sun and it is around 9 times bigger. One of the coolest things about this star is just how well we know it! According to Jim Kaler’s excellent information; “Recent accurate measures of angular diameter by the Navy Interferometer show it to be 0.00254 seconds of arc across (the separation of car headlights seen from a distance of 80,000 kilometers, 20 percent of the way to the Moon), which gives it a physical diameter 8.2 times that of the Sun, the agreement with the previously calculated diameter showing that we know the size, temperature, luminosity, and distance very well.”

Now, get out your telescope and let’s go on a galaxy hunt. Our first target is NGC 3486 (RA 11:00.4 Dec +28:58). At magnitude 10, this barred spiral galaxy discovered by Sir William Herschel is around 33 million light years away and it has attitude. Even in a small telescope, observers will note a bright, sharp nucleus and larger instruments will reveal a strong central bar and patchy structure that is the signature of a Seyfert galaxy.

Next up is a large telescope challenge – NGC 3344 (RA 10:43.31 Dec +24:55). Located much closer to the Milky Way Galaxy at 25 million light years in distance, this 13th magnitude grand design spiral galaxy is a face-on presentation, and only about half the size of our own galactic home. Like our preceding observation, it, too, has a central bar – but don’t be fooled by the foreground stars! According to studies done by Verdes-Montenegro (et al), the bar is exponential and dominates the central parts, while the bulge component is small. This makes this faint customer belong to the classification of a “ringed galaxy”.

Sources: SEDS, Wikipedia
Chart Courtesy of Your Sky.