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Gamma-ray Bursts (GRBs) are the most powerful explosions in the universe. In a few seconds they release a tremendous amount of energy outshining billions of stars. They were first discovered (accidentally) in 1967 by satellites designed to detect tests of nuclear weapons. Although we detect new GRBs on daily basis, no one knows the exactly the process behind their origin.

The most-widely accepted model proposes that GRBs are created in a gravitational collapse of extremely massive stars into black holes when matter in the accretion disk is heated by neutrinos and driven into narrowly focused jets along the rotational axis.

As the core of a massive star in a distant galaxy collapses, deep inside, twin beams of matter and energy begin to blast their way outward. Within seconds, the beams have eaten their way out of the star, and observers at Earth see it as a gamma-ray burst, GRB 060729A - Credit for caption: Phil Plait SSU NASA E/PO; Images: Aurore Simonnet SSU NASA E/PO

Nevertheless, this model makes it difficult to explain long GRBs with the duration of more than 100 seconds and cannot account for afterglows lasting up to 10,000 observed by the Swift spacecraft.

Professor Komissarov and his colleagues at the University of Leeds accredit the creation of the matter jets to a magnetic mechanism and examine the close binary scenario involving a merger or a WR star (evolved, massive star of over 20 solar masses) with a neutron star or a black hole, in their article Close Binary Progenitors of Long Gamma Ray Bursts.

“The neutrino model cannot explain very long gamma ray bursts and the Swift observations, as the rate at which the black hole swallows the star becomes rather low quite quickly, rendering the neutrino mechanism inefficient, but the magnetic mechanism can.”

Although the Chandrayaan 1 mission by the Indian Space Research Organization (ISRO) ended prematurely when scientists lost contact with the spacecraft on August 28, 2009, the agency claimed it to be a grand success in that it completed its major tasks.

Apart from the primary objectives to prepare a 3D atlas with the resolution of up to 10-5m and chemical and mineralogical mapping of the entire lunar surface, the terrain mapping camera on board the spacecraft has also sent images of the landing site of Apollo 15 and the tracks of land rovers astronauts used to travel on the lunar surface.

Apollo 15 lunar module, Falcon - Image Credit: NASA/Goddard Space Flight Center/Arizona State University

Analysis of data from the onboard Terrain Mapping Camera (TMC) and the Hyper Spectral Imager (HySi) revealed disturbances on the the lunar surface show tracks on Lunar Roving Vehicles (LRV) used by astronauts on Apollo 15, 16 and 17.

That’s right, all your Moon landing deniers (read crazy people). Here are photos and data acquired by instruments built by an agency from a different country on board a spacecraft launched into lunar orbit independently of NASA – Chandrayaan 1 also carried NASA instruments but the TMC was built in ISRO’s Space Applications Centre (SAC).

I’m truly curious how Moon hoaxers tackle this one. Meanwhile, the rest of us who live in a real world will no doubt enjoy in awe all other wonders of the universe.

Galaxy Zoo is a highly successful citizen science project. It harnesses the power of the Internet and the great ability of human brain to recognize patterns and shapes (something computers are notoriously hard to “teach”) to classify a million of galaxies. The data is provided by the Sloan Digital Sky Survey (SDSS) using a dedicated 2.5 m f/5 modified Ritchey-Chretien altitude-azimuth telescope located at Apache Point Observatory, in south east New Mexico.

It is not uncommon in science to make accidental discoveries. Alexander Fleming certainly did not intend to contaminate one of his research cultures with a Penicillium genus. Arno Penzias and Robert Woodrow Wilson discovered the cosmic microwave background radiation because of their “inability” to account for the 3.5 K excess temperature of their radiometer. Thomas Bopp (co)discovered the most observed comets of the 20th century when looking at the globular cluster M70 (and actually did not even own a telescope at the time).

Other times, data from a research project with a specific goal can be used to make discoveries never anticipated by the project team. Several Galaxy Zoo participants noticed interesting artifacts present in images of galaxies from the SDSS. The rainbow-like artifact in the image below is actually an asteroid.

Galaxy designated as SDSS J130941.81+063637.8 with an asteroid trail - Image Source: SDSS

The SDSS instruments use couple-charged device (CCD) cameras to collect light. A CCD chip can be thought of as a 2 dimensional array of light collectors that accumulate electric charge proportional to the intensity of incident light. The electric charge is then converted to voltage in a charge amplifier and digitized by a computer to create an image. CCD data in astronomy is used to create (only) gray-scale images. To make a color image, the camera takes exposures with different filters. The individual filter images can be later combined into a single color image (similar to combining the  R, G and B channels of a color picture).

The SDSS camera uses five different filters: u (ultraviolet), g (green), r (red), i and z (both infrared). Thus, five exposures are required to produce an image of any single region of the sky. The actual order in which the filters are used is r, i, u, z and g. Although SDSS takes images through five filters, only three are combined to produce colored pictures. The i filter makes the red picture, r filter makes the green picture, and the g filters makes the blue picture.

Because of the technique called “drift-scanning” employed by the SDSS, exposure through a single filter takes roughly 54 seconds. Since asteroids are relatively close to us, they move rather quickly across the sky. This motion is easily noticeable at the resolution of 0.396 arc second per pixel achieved by SDSS. Furthermore, because of the order in which different filters are used, the red and green streaks are closer together and for slower moving objects may even be combined into single yellow/orange/brown streak. The dark blue/violet streak, however, is always easily recognizable at a sufficient distance from the other two (because the g filter is used last) .

Galaxy designated as SDSS J105646.89+050055.3 with an asteroid trail beneath it - Image Source: SDSS

The animation below shows what happens when the SDSS’s filters scan a part of sky with a slow-moving asteroid. The asteroid is the brown dot moving across the animation. The animation shows the camera’s r, i, and g filters sweeping across the sky. (In reality, it works the opposite – the cameras stay still and the sky moves during the night.) The camera takes a picture of the asteroid through the r and i filters (which are next to one another), leaving a yellow dot (or red and green dots). When the g filter scans the asteroid, the asteroid has moved; it shows up as a blue dot in its new place. In the last frame of the animation, the asteroid is removed, leaving only the image that would be seen by the SDSS.

Although SDSS is focused on looking for distant galaxies and quasars, it also sees objects in our cosmic neighborhood. The first data release (SDSS DR1) alone contains more than 100,000 asteroids. Occasionally, it manages to photograph a wobbling satellite in low-earth orbit (below) and even a bright meteor (below).

A satellite in Low Earth Orbit captured by SDSS camera using the r filter. The discontinuity in the satellite's path is a result of the data for that particular area being taken at different time - Image Source: SDSS

Bright meteor captured in the act of burning up in the earth's atmosphere. The trail is colored green because the image of the meteor was captured in only one of the 5 SDSS filters - Image Source: SDSS

Update: I met a lot of interesting people at the Science Online London 2009 conference last Saturday. One of them was Arfon Smith who is the technical lead on Galaxy Zoo. We was kind enough to demonstrate for me the first prototype of the Moon Zoo web interface and let me tell you – even though it is just the first prototype, it was sweet!

Moon Zoo will be another citizen science project, the latest incarnation of the highly successful Galaxy Zoo. The project will use high resolution images from the Lunar Reconnaissance Orbiter Camera (LROC) on NASA’s LRO spacecraft. Moon Zoo will ask the participants to classify and measure the shape of features on lunar surface with the main focus on:

• counting the number of and measuring the size of impact craters
• categorizing locations of interest such as lava channels, crater chains, lava flooded impact craters,  volcanic eruptive centers, etc.
• assessing the degree of boulder hazard by comparing boulder density on two images
• identifying recent changes on lunar surface by comparing LRO and Apollo photographs
• determining the location of space mission hardware on the Moon (Apollo landers, Luna rovers, European and Chinese probes)

Besides delivering high quality data which will (hopefully) address many questions of lunar science, Moon Zoo will also be an excellent tool to promote lunar and space exploration and engage the public in learning about processes involved in scientific discoveries. Moon Zoo is expected to be even more popular than Galaxy Zoo, exploiting the media exposure of the 40th anniversary of Apollo 11 and the recent NASA’s LRO/LCROSS mission.

Full resolution detail from one of the first LROC NAC images. At this scale and lighting, impact craters dominate the landscape. Two general types of impact craters are readily identifiable. Solitary craters which most likely represent a single impact event, and clusters or chains of small, fresh craters produced by the impact of lunar material excavated by a larger impact. Image width is 1400 meters, north is down - Photo Source: NASA/GSFC/Arizona State University

When the original Galaxy Zoo was launched in summer of 2007, hardly anyone could anticipate the enormous participation and the enthusiasm with which thousands of users meticulously classified millions of galaxies. Because of the immense success of the original project, Galaxy Zoo 2 was created to focus on a detailed classification of 245,609 galaxies selected from millions of classifications available. Galaxy Zoo 2 participants answer the kind of questions the creators of the original Galaxy Zoo project would have asked had they known how large the users base was going to be.

Earlier this month the Zoo project family was extended by Galaxy Zoo Supernovae (currently in a planned off-time to analyze preliminary data). The Supernovae project uses images from the Palomar Transient Factory (PTF) taken only hours earlier. The PTF data is fed through an automated pipeline which finds suitable candidates to display to users. Because time (the age of a supernova) is of the essence for this type of research, unlike in Galaxy Zoo 1 and 2, GalaxyZoo Supernovae implemented a priority queue to always display the most recent candidates before showing older data. This system presents a unique opportunity for anyone to discover a never-before-seen supernova.

A supernova found in on of the Galaxy Zoo Supernovae candidate assets - Photo Source: GalaxyZoo.org

Galaxy Zoo project was the first of its kind to use the exceptional power of human brain to recognize patterns and shapes (something that computers “learn” with great difficulties). More importantly, Galaxy Zoo proved that worldwide citizen science projects can provide data analysis comparable in quality to professional astronomers. The large number of independent results by amateurs or enthusiasts has an advantage over a significantly smaller number of results by experts because it allows to quantify uncertainties with ease.

Update: The submission deadline for new message has passed. The packed is now being converted and packaged to be transmitted on August 29.

If you sometimes get tired of talking to your fellow Earthlings, consider sending a message to beings who could be living 20.3 light years away via the HelloFromEarth website.

HelloFromEarth is a project created by COSMOS magazine for National Science Week in Australia in collaboration with Australia’s Department of Innovation, Industry, Science and Research and NASA, that enables anyone to send a short message to the potential inhabitants of the planet designated as Gliese 581 d.

Artist's impression of Gliese 581 d

Gliese 581 d is an extrasolar planet in the constellation Libra about 20.3 light years away from our solar system. It orbits a red dwarf (Gliese 581) at a distance of 0.22 AU – well within the habitable zone of the star, where liquid water could exists.

Artist's impression of the planetary system around the red dwarf Gliese 581. In the foreground planets Gliese 581 c and Gliese 581 b with super-Earth Gliese 581 d in a closeup - Source: ESO

Until now, almost 19,000 messages from all around world have been collected for Glieseans to read. Submissions are accepted until August 24, after which the data will be send to NASA’s JPL in California to be encoded into binary form and packaged for transmission. JPL will then send the data back to Canberra Deep Space Communication Complex at Tidbinbilla, known as the Deep Space Station 43 (DSS43), which has for years been providing communication for NASA’s interplanetary missions. The 40-year-long wait for a potential response will begin August 29, 2009 when the 70-meter main antenna at DSS43 will transmit the signal aimed towards the Gliese 581 system.

Click here to send your message to Glieseans.

Here are a few selected submissions:

These are not the droids you’re looking for. Don – Denton, TX, United States

We are all lying in the gutter, but some of us are looking at the stars… Jeff N – Sydney, Australia

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 101. Sam -Adelaide, Australia

All truth passes through three stages: first, it’s ridiculed; second, it’s violently opposed and third, it’s accepted as self-evident. It’s time to contact us! Simone – Latina, Italy

To Mr. Alien. I’ve got some jokes for you. Knock Knock. Who’s there. Rocket. Rocket who. Rockets coming to tickle you!! Watch out. See you later, Jack – Melbourne , Australia

We’ve been trying, but can’t read your crop circles. Tatyana – Seattle, WA, United States

Does “Santa” visit your planet? Have a happy holiday. Jan Kurrels – Canberra, Australia

What is the purpose of life? What is the universe and is there something beyond it? Can we reach your level of evolution one day? Pls answer. Bojidar -Sofia, Bulgaria

This is a chain SMS. Please send this forward to 10 new civilizations within a century and something good will happen to you. Kari-Pekka Arola – Tampere, Finland

Live Long and prosper. Miranda – Cleveland, United States

Please send the Cylon Number Six in the red dress. Craig Cormick -Canberra, Australia

NASA scientists announced that the analysis of sample materials returned to Earth by the capsule from the Stardust spacecraft whose primary mission was to investigate the coma of comet Wild 2 revealed the presence of Glycine – the smallest of the 20 amino acids commonly found in proteins and one of the most fundamental building blocks of life. The discovery supports the hypothesis that the basis ingredients of life  have been brought to our planet by comets (and meteorites).

Although Glycine was found in the Wild 2 samples earlier, scientist were not able to rule out a possible contamination by sources on Earth. Only the recent analysis of isotopes of carbon (basic building blocks of all organic molecules) revealed concentrations of Carbon-13 too high to have originated on our planet, thus proving the extraterrestrial nature of the molecules.

The Stardust interplanetary spacecraft was launched at 21:04:15 UTC on February 7, 1999. On January 15, 2006 Stardust flew by the Earth and released a capsule with sample material. Currently, it is en route to the comet Tempel 1 with a scheduled fly by on February 14, 2011.

The Stardust spacecraft is launched on a Delta II rocket from Launch Pad 17-A, Cape Canaveral Station on February 7, 1999 at 21:04:15 UTC - Photo Source: NASA

NASA's Stardust sample return capsule successfully landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC on January 15, 2006 - Photo Source: NASA

Image of Comet Wild 2 from NASA's Stardust spacecraft - Photo Source: NASA/JPL