A before and after animation of Supernova 2010lt. Credit: Dave Lane
A ten-year old girl from Canada has discovered a supernova, making her the youngest person ever to find a stellar explosion. The Royal Astronomical Society of Canada announced the discovery by Kathryn Aurora Gray of Fredericton, New Brunswick, (wonderful middle name!) who was assisted by astronomers Paul Gray and David Lane. Supernova 2010lt is a magnitude 17 supernova in galaxy UGC 3378 in the constellation of Camelopardalis, as reported on IAU Electronic Telegram 2618. The galaxy was imaged on New Year’s Eve 2010, and the supernova was discovered on January 2, 2011 by Kathryn and her father Paul.
7 years on Mars for Spirit and Opportunity. Poster by Glen Nagle. Click for access to downloadable versions.
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Today, January 3, 2011, is the 7th anniversary of the Spirit rover landing on Mars. In their tradition, Glen Nagle and Stu Atkinson from Unmanned Spaceflight have teamed up to create a poster and poem combo to celebrate. The poster includes scenes from both Spirit’s and Opportunity’s adventures – Glen and Stu challenge you to see how many places you can name. Click on the images or visit Glen’s Astro0 website for higher resolution versions that you can download to print a poster or use for wallpaper.
And happy anniversary to the Mars Exploration Rovers and their science and engineering teams!
MER poster with poem by Stu Atkinson. Image by Glen Nagle. Click for access to higher resolution versions.
In just a few hours the peak of the first meteor shower of 2011 will begin – the Quadrantids. Where did these mysterious meteors begin their life and how can you observe one yourself? Then step inside…
Beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower sparkles across the night sky for nearly all viewers around the world. Its radiant belongs to an extinct constellation once known as Quadran Muralis, but any meteors will seem to come from the general direction of bright Arcturus and Bootes. This is a very narrow stream, which may have once belonged to a portion of the Aquarids, but recent scientific data points to a what may have been a cosmic collision. According the most recent data, the Quandrantid meteors may have been formed about five centuries ago when a near-Earth asteroid named 2003 EH1 and a comet smashed into one another. Historic records from ancient China put comet C/1490 Y1 in the path of probability.
As Jupiter‘s gravity continues to perturb the stream, another 400 years may mean this shower will become as extinct as the constellation for which it was once known, but we aren’t out of the running just yet. “Peaking in the wee morning hours of Tuesday, Jan. 4, the Quads have a maximum rate of about 100 per hour (varies between 60 and 200),” says Bill Cooke of NASA’s Meteoroid Environment Office. “What makes this year so special is that the Moon is New on the night of the peak, so there will be no interference from moonlight.”
As exciting as it may seem, there are a few problems associated with observing the Quadrantid meteor shower. The first is the weather, because this northern hemisphere show occurs during a notoriously cold season making observations uncomfortable at best. The second is the brevity of the activity itself. Because Earth intersects the debris orbit of 2003 EH1 at a perpendicular angle, we zip right through the trail. That’s why the shower activity is so fast and slightly unpredictable. A third consideration is the high probability of cloud cover – but take heart… NASA has you covered!
“Got clouds? No problem.” says SpaceWeather. “You can stay inside and listen to the Quadrantids. Tune into SpaceWeather Radio for a live audio stream from the Air Force Space Surveillance Radar. When a Quadrantid passes over the facility, you will hear a “ping” caused by the radar’s powerful transmitter echoing from the meteor’s ion trail. During the shower’s peak, the soundtrack is guaranteed to entertain.
So where and when to look? “You can start watching after 2:30am in the North to North East look between the handle of the Big Dipper -Ursa Major and the Constellation of Bootes or the Kite shaped constellation, this is the radiant location as the Meteors will appear to radiate from this general area.” says professional astrophotographer, John Chumack. “Or after 2:30am simply look between the North Star and bright star Arcturus in the East. The Quadrantid Meteors will appear to be coming from this general area of the sky. There is no moon present during this year’s shower, so you can watch all night if you like without moonlight interfering, but the best time will be after 2:30am. As the night goes on the Big Dipper, Bootes and Arcturus climb higher into the sky, so keep watching because the number of meteors usually picks up after 2:30am and gets better through 6:00am. as Earth rotates into the stream. Meteors can appear anywhere in the sky, so look in all directions of the sky as the Quadrantid radiant reaches straight over head. The Quadrantid Meteors are rather fast movers. They enter the atmosphere at about 90,000 to 120,000mph, and can have some impressive long trails.”
Will the Quadrantid Meteor Shower live up to its expectations? No one knows for sure… But we’ll be watching!
Many thanks to John Chumack of Galactic Images for his inspiring photo and to NASA for the locator chart. We thank you so much!
[/caption]The end of the space shuttle’s service life lies nigh before us. There’s no surprise then that reviews are coming out as with Robert Adamcik’s “Voyages of Discovery: The Missions of United States Space Shuttle Discovery (OV-103) 1984-2011“. This book’s faithful compilation of the shuttle, mission by mission, reminds us that we are a successful space faring species with high potential.
Billed as the first production orbiter, Discovery was optimized to haul cargo from the Earth’s surface up to low Earth orbit. Its somewhat extended 5 year build time from about 1979 to 1984 was followed up with 27 years of service. During its operational time, the shuttle will have flown to orbit a total of 39 times. The future tense is appropriate as the shuttle awaits it final flight in early 2011.
The book’s account of this shuttle’s operations is succinct and thorough. The author allocates a chapter to each mission and each chapter lies in chronological order. Each chapters’ format is routine; the mission title, a paragraph or two on noteworthy issues, then crew identities, shuttle payload and usually a paragraph describing each day in orbit. While not particularly imaginative, this makes for a business like rendition of this shuttle’s flights.
Many small black and white pictures greatly add to the prose. Most are of the Discovery whether taking off, in flight or landing. Many exciting pictures of roving astronauts or drifting satellites demonstrate the business end of the orbiter. As well, each chapter includes a copy of the mission patch and many have a posed picture with all the crew members or with a crew member working in the low gravity environment. Often the pictures serve to demonstrate a point in the adjoining text whether a woodpecker damaging the shuttle before flight or a flat tire experienced after landing. In all, these visual treats wonderfully spice up the pages.
Yet, this book does leave some questions. Paramount is “Why prepare a book compiling all the missions when this shuttle has at least one more to do?”. And, “Why was a synopsis created for the Discovery rather than any of the other shuttles?”. Most of perplexing of all though is the book’s lack of a summary. With the shuttle’s service life ending and having completed 39 missions, it needs an all-round perspective on the shuttle’s contributions to humanity. Rather, the book makes for an effective reference for the mission of Discovery but not for a consideration of the shuttle’s over-arching value.
Currently, we are seeing many new opportunities arise in space travel; whether private launch vehicles or newly successful national space agencies. Changes will continue as we learn from our experiences and profit from new capabilities. The shuttle Discovery, ably presented by Robert Adamcik in his book “Voyages of Discovery: The Missions of United States Space Shuttle Discovery (OV-103) 1984-2011” shows how one vehicle was a robust link in the change. Even as the shuttle program winds down, changes present new opportunities for us to adventure into space.
Wanahani outlook at Santa Maria Crater. Opportunity took this panaromic mosaic from “Wanhani” just meters from the crater rim on Dec 29, 2010 (Sol 2464). Note rover tracks near rim at left, relatively clean solar panel at right and numerous ejecta rocks. CRISM mapper results suggest water bearing materials are located at the southeastern edge of the rim located at the southeastern section of the crater. Portions of distant Endeavour Crater are faintly visible as bumps on the horizon in the background. Mosaic Credit: NASA/JPL/Cornell, Ken Kremer, Marco Di Lorenzo
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A robot from Earth is celebrating New Years on Mars by snapping another amazing set of “Postcards from the Edge” while perched near the sharp edge of a crater cliff on the red planet. NASA’s Opportunity rover is now stationed just meters away from a new precipice at the stunningly beautiful crater named Santa Maria. The twin rovers mark their 7th anniversary on Mars this week. See martian postcard mosaics above and below.
Craters expose the hidden history of Mars and permit scientists a path to explore the past geologic epochs which otherwise would remain buried and inaccessible.
Santa Maria Crater from Orbit. Opportunity arrived at the western rim of Santa Maria Crater, some 90 meters wide, on Dec. 16, 2010 at a spot called “Palos”. Opportunity then drove in a counterclockwise direction to a spot called “Wanahani” at the southern edge. It is collecting high resolution imagery and spectral data over New Years and will then resume driving to its next destination at the Southeast rim, an area nicknamed “Yuma”. See new annotations. Researchers are using data collected by the CRISM mineral mapping spectrometer aboard NASA’s Mars Reconnaissance Orbiter (MRO) to direct the route which Opportunity is traversing on Mars during the long term journey to Endeavour crater. Spectral observations recorded by CRISM indicates the presence of water-bearing sulfate minerals at the location shown by the red dot on the southeast rim crater whereas the crater floor at the blue dot does not. This image was taken by the High Resolution Imaging Science Experiment (HiRISE) camera also on MRO. Credit: NASA/JPL-Caltech/Univ. of Arizona. Santa Maria is an exciting find because it appears to be relatively new and unweathered – on the order of possibly just a few million years old. Researchers are eager to drive around the rim in order to explore deposits of water bearing minerals that contain valuable clues to the flow of liquid water on ancient Mars.
The golf cart sized rover arrived this week (Dec. 29) at an outlook nicknamed “Wanahani” near the southern edge of Santa Maria. Opportunity arrived at the western rim of Santa Maria on Dec. 16. Just before Christmas, she drove about 20 meters south along the steep rim from the initial location at Palos Promontory and then bumped incrementally further up to the edge (Sol 2464) .
Palos Promontory and Santa Maria Panorama from Opportunity on Mars.
Opportunity drove within 2.5 meters of the rim and snapped this beautiful panoramic vista of the crater and distant horizon on Sol 2454. Note rover solar panel deck, antennae and sundial at left. Mosaic Credit: NASA/JPL/Cornell, Oliver de Goursac.Santa Maria from Palos Promontory on Mars.
Opportunity drove to within 2.5 meters of the rim and snapped this gorgeous panoramic vista unveiling the whole interior on Sols 2453 & 2454. Note the steep walls and sand dunes on the floor. Mosaic Credit: NASA/JPL/Cornell, James CanvinWanahani outlook at Santa Maria Crater.
Opportunity took this panaromic mosaic from “Wanhani” just meters from the crater rim on Dec 29 (Sol 2464). Note rover tracks near rim at left, solar panel at right and numerous ejecta rocks. CRISM mapper results suggest water bearing materials are located at the southeastern section of the crater. Portions of distant Endeavour Crater are faintly visible as bumps on the horizon in the background. Mosaic Credit: NASA/JPL/Cornell, Ken Kremer, Marco Di LorenzoCrater Rim Duo with Signs of Hydates on Mars.
Santa Maria rim up close (80 meters away) and Endeavour rim (6 km away) on the horizon in the distance. Both craters show mineralogical evidence for the past flow of liquid water on Mars and are high priority science targets. Mosaic Credit: NASA/JPL/Cornell, Ken Kremer, Marco Di LorenzoPartial panorama near Wanahani outlook on Sol 2461.
Undulating sand dunes on the crater floor and southern portion of Santa Maria, inclined about five degrees. Mosaic Credit: nasatech.net
But there is no time to party and relax. The rover will soon resume driving to the next location – nicknamed “Yuma”. It will continue farther around the football field sized crater – measuring some 90 meters (295 ft) in diameter – to reach the exposures of sulfated hydrates located at the southeast portion of the crater near “Yuma”.
Opportunity must be in position at an important science target before mid January and the onset of solar conjunction and a temporary communications black out with Earth. The rover will remain stationary during conjunction.
Fish eye view from Wanahani outlook. Opportunity snapped this wide angle view from the crater rim of Santa Maria with the hazard camera on Sol 2464. Credit: NASA/JPL/Cornell
At Wanahani, Opportunity is now hurriedly toiling away over the New Year’s period to collect a pair of long baseline, high resolution stereo image mosaics using it’s panoramic, multispectral imaging camera. See our initial Wanahani mosaics assembled here from the navigation camera images just received on Earth (Sol 2464).
The team is using all 13 filters on the filter wheels of the panoramic camera, according to Ray Arvidson, the deputy principal investigator for the rovers, in an interview from Washington University in St. Louis. Over the course of several days, the left and right “eyes” of the panoramic camera will gather data at various wavelengths to maximize the collection of spectral information about the hydrated minerals located in the craters interior.
Data downlink is limited by the available amount of flash memory aboard Opportunity and is the Achilles heel of rover operations. Virtually all the pictures and science is streaming back to Earth via NASA’s long lived Mars Odyssey orbiter. The team is working to get all the acquired science data offloaded as swiftly as possible,
A functioning replica of the Santa Maria in Funchal harbor, Madeira Islands, Portugal.
Arvidson said that the team hopes that the meteor impact that excavated the crater also blasted some of these scientifically fascinating rocks free to spots which are more easily accessible – just outside the rim for close up analysis. Additional imaging and spectral data is also being collected from Mars orbit this new year’s weekend in hopes of quickly directing the rover to the best locations for science in the limited time available.
Opportunity will study the relatively fresh and uneroded ejecta rocks using all the instruments located at the end of the robotic arm. One target will be selected for a longer duration study during the period of solar conjunction, said Arvidson.
The Santa Maria replica at sea. Opportunity is on an epic expedition to a distant horizon far beyond the shores of Earth. The rover team is naming places visited around the crater rim after islands visited by Columbus during his voyages of expedition and discovery to the New World starting in 1492. The Santa Maria was the largest of the three ships used during his first voyage.
Opportunity will resume her long term trek to Endeavour crater after the end of solar conjunction in mid February. The western rim of Endeavour is about 6 km distant. Endeavour is a very compelling science target because it shows significant signatures for clay minerals which formed in the presence of neutral bodies of liquid water on Mars, billions of years ago.
Spirit and Opportunity celebrate 7 Years on Mars this month since the dynamic duo landed in January 2004. Look for my story soon.
This year we’re in for a real treat! The citizens of planet Earth will be treated to not one – but four – partial solar eclipses and the first will begin on January 4. Ready to find out where and when? Then step inside….
Courtesy of NASA (click to animate)The first partial solar eclipse 2011 is scheduled for January 4th, 2011, and will be seen in Europe, Africa and Central Asia. This eclipse will begin at 06:40:11 UT (Universal Time)) and culminates at 11:00:54 UT. The greatest eclipse – the point of time when the distance between the Moon’s shadow axis and Earth’s center is the minimum – will happen at 08:50:35 UT over northern Sweden. If you live in northern Africa, the Middle East and Central Asia, you will be able to witness this eclipse.
If you’re planning on watching, remember eye safety and use a proper solar filter for telescopes and binoculars. If it’s too late to get a filter or your budget won’t allow, why not try building your own pinhole projector? Get two pieces of cardboard – one will need to be white or have white paper attached to it for the screen. Cut a small square in the other piece of cardboard, and tape aluminum foil over the square. Now make a pinhole in the middle of the foil. This is your “projector”. With the Sun behind you, hold the pinhole projector as far away from the screen as you can. The farther away you are from the screen, the bigger your image will be. You won’t be able to see fine details like sunspots, but you’ll easily see the changes as the Moon passes over the face of the Sun!
Don’t be upset if you don’t catch this eclipse. The next will happen on June 1, 2011 and be for the eastern region of Asia, northern region of North America and some islands of the North Atlantic. Again? How about July 1, 2011 and this time be over the Indian Ocean and the small islands in this ocean. Still not found you? Then how about November 25, 2011 and southern regions of Africa and Australia and whole of Antarctica!
Want to watch the eclipes live? Then join the cast and crew at Bareket Observatory and at AstronomyLive.com!
Anyhow, this prompted me to look up different ways in which apparent superluminal motion might be generated, partly to reassure myself that the bottom hadn’t fallen out of relativity physics and partly to see if these things could be adequately explained in plain English. Here goes…
1) Cause and effect illusions
The faster than light pulsar story is essentially about hypothetical light booms – which are a bit like a sonic booms, where it’s not the sonic boom, but the sound source, that exceeds the speed of sound – so that individual sound pulses merge to form a single shock wave moving at the speed of sound.
Now, whether anything like this really happens with light from pulsars remains a point of debate, but one of the model’s proponents has demonstrated the effect in a laboratory – see this Scientific American blog post.
What you do is to arrange a line of light bulbs which are independently triggered. It’s easy enough to make them fire off in sequence – first 1, then 2, then 3 etc – and you can keep reducing the time delay between each one firing until you have a situation where bulb 2 fires off after bulb 1 in less time than light would need to travel the distance between bulbs 1 and 2. It’s just a trick really – there is no causal connection between the bulbs firing – but it looks as though a sequence of actions (first 1, then 2, then 3 etc) moved faster than light across the row of bulbs. This illusion is an example of apparent superluminal motion.
There are a range of possible scenarios as to why a superluminal Mexican wave of synchrotron radiation might emanate from different point sources around a rapidly rotating neutron star within an intense magnetic field. As long as the emanations from these point sources are not causally connected, this outcome does not violate relativity physics.
2) Making light faster than light
You can produce an apparent superluminal motion of light itself by manipulating its wavelength. If we consider a photon as a wave packet, that wave packet can be stretched linearly so that the leading edge of the wave arrives at its destination faster, since it is pushed ahead of the remainder of the wave – meaning that it travels faster than light.
However, the physical nature of ‘the leading edge of a wave packet’ is not clear. The whole wave packet is equivalent to one photon – and the leading edge of the stretched out wave packet cannot carry any significant information. Indeed, by being stretched out and attenuated, it may become indistinguishable from background noise.
Also this trick requires the light to be moving through a refractive medium, not a vacuum. If you are keen on the technical details, you can make phase velocity or group velocity faster than c (the speed of light in a vacuum) – but not signal velocity. In any case, since information (or the photon as a complete unit) is not moving faster than light, relativity physics is not violated.
3) Getting a kick out of gain media
You can mimic more dramatic superluminal motion through a gain medium where the leading edge of a light pulse stimulates the emission of a new pulse at the far end of the gain medium – as though a light pulse hits one end of a Newton’s Cradle and new pulse is projected out from the other end. If you want to see a laboratory set-up, try here. Although light appears to jump the gap superluminally, in fact it’s a new light pulse emerging at the other end – and still just moving at standard light speed.
Light faster than light. Left: Stretching the waveform of light can make the leading edge of the wave seem to move faster than light. Right: Gain media can act like a Newton's Cradle, making light seem to jump the gap superluminally.
4) The relativistic jet illusion
If an active galaxy, like M87, is pushing out a jet of superheated plasma moving at close to the speed of light – and the jet is roughly aligned with your line of sight from Earth – you can be fooled into thinking its contents are moving faster than light.
If that jet is 5,000 light years long, it should take at least 5,000 years for anything in it to cross that distance of 5,000 light years. A photon emitted by a particle of jet material at point A near the start of the jet really will take 5,000 years to reach you. But meanwhile, the particle of jet material continues moving towards you nearly as fast as that photon. So when the particle emits another photon at point B, a point near the tip of the jet – that second photon will reach your eye in much less than 5,000 years after the first photon, from point A. This will give you the impression that the particle crossed 5,000 light years from points A to B in much less than 5,000 years. But it is just an optical illusion – relativity physics remains unsullied.
5) Unknowable superluminal motion
It is entirely possible that objects beyond the horizon of the observable universe are moving away from our position faster than the speed of light – as a consequence of the universe’s cumulative expansion, which makes distant galaxies appear to move away faster than close galaxies. But since light from hypothetical objects beyond the observable horizon will never reach Earth, their existence is unknowable by direct observation from Earth – and does not represent a violation of relativity physics.
And lastly, not so much unknowable as theoretical is the notion of early cosmic inflation, which also involves an expansion of space-time rather than movement within space-time – so no violation there either.
Other stuff…
I’m not sure that the above is an exhaustive list and I have deliberately left out other theoretical proposals such as quantum entanglement and the Alcubierre warp drive. Either of these, if real, would arguably violate relativity physics – so perhaps need to be considered with a higher level of skepticism.
The signatures of a bubble collision at various stages in our analysis pipeline. A collision (top left) induces a temperature modulation in the CMB temperature map (top right). The "blob" associated with the collision is identi ed by a large needlet response (bottom left), and the presence of an edge is determined by a large response from the edge detection algorithm (bottom right). (Feeny, et al.)
In the realm of far out ideas in science, the notion of a multiverse is one of the stranger ones. Astronomers and physicists have considered the possibility that our universe may be one of many. The implications of this are somewhat more fuzzy. Nothing in physics prevents the possibilities of outside universes, but neither has it helped to constrain them, leaving scientists free to talk of branes and bubbles. Many of these ideas have been considered untestable, but a paper uploaded to arXiv last month considers the effects of two universes colliding and searches for fingerprints of such a collision of our own universe. Surprisingly, the team reports that they may have detected not one, but four collisional imprints.
A technician begins to remove thermal sensors and foam insulation from space shuttle Discovery's external fuel tank in the Vehicle Assembly Building. Photo Credit: NASA/Frank Michaux
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Discovery’s woes deepened this week with NASA engineers finding even more cracks in the orbiter’s external tank. The first crack was noted shortly after a leak was discovered on the Ground Umbilical Carrier Plate (GUCP) Nov. 5. After the first crack was found, technicians found a second and then a third. NASA found the crack on support beams dubbed ‘stringers’ around the intertank region of the tank. They applied what is known in the business as a doubler, a section of metal that is twice as thick as the original – this is done to strengthen the affected area.
On Dec. 17, a tanking test was conducted on the tank. Some 89 instruments were attached to the outside to monitor the tank as it was filled with super-cold liquid oxygen and hydrogen. The external tank can shrink by as much as an inch when these extremely cold liquids enter the tank. As one might imagine, this creates great stress on the tank, as such mission managers had the orbiter rolled back into the Vehicle Assembly Building (VAB) for X-Ray scans and other tests.
These tests are considered to be ‘non-destructive’ but NASA is not able to conduct them out at launch complex 39A. Testing started as soon as the full stack consisting of the orbiter, ET and twin solid rocket boosters were in the VAB.
It is unknown when Discovery will be back at LC39A for her final mission, STS-133. Photo Credit: Alan Walters/awaltersphoto.com
However, once these scans were completed – NASA had more problems, more cracks were found. Four cracks were found hiding beneath the foam on the side of the ET that faces away from Discovery. Mission managers will now weigh whether-or-not they will go ahead with repairing the damaged section of the ET. They are scheduled to make a final determination on Monday, Jan. 3. If they elect to do so, the repairs will be conducted inside of the VAB and not out at the pad.
STS-133 is a resupply flight to the International Space Station (ISS). When it does launch, it will carry the modified Leonardo Permanent Multipurpose Module (PMM) to the orbiting outpost. Contained within that is the first human-like robot to fly into space – Robonaut-2 (R2). Currently, Discovery is scheduled to launch no-earlier-than Feb. 3 at 1:37 EDT. This mission will mark the 39th time that Discovery has taken to the Florida skies and will be the final scheduled mission in the orbiter’s career.
Discovery's final crew may have to wait a while longer before they can start their mission. Image Credit: NASA
