30
Apr 11

Swift and Hubble Probe Asteroid Collision Debris

Source: NASA News


Hubble Space Telescope image of (596) Scheila.
Image credits: NASA/ESA/D. Jewitt (UCLA).

Late last year, astronomers noticed an asteroid named Scheila had unexpectedly brightened, and it was sporting short-lived plumes. Data from NASA's Swift satellite and Hubble Space Telescope showed these changes likely occurred after Scheila was struck by a much smaller asteroid.

"Collisions between asteroids create rock fragments, from fine dust to huge boulders, that impact planets and their moons," said Dennis Bodewits, an astronomer at the University of Maryland in College Park and lead author of the Swift study. "Yet this is the first time we've been able to catch one just weeks after the smash-up, long before the evidence fades away."

Asteroids are rocky fragments thought to be debris from the formation and evolution of the solar system approximately 4.6 billion years ago. Millions of them orbit the sun between Mars and Jupiter in the main asteroid belt. Scheila is approximately 70 miles across and orbits the sun every five years. (read more)

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29
Apr 11

Voyager's Golden Record

Source: NASA Science News


The Golden Record. Image credit: NASA.

 

NASA's Voyager probes are at the edge of the solar system carrying a message to possible extraterrestrial civilizations.  Highlights include greetings from humans and whales, some of Earth's greatest music, and the brainwaves of a young woman in love. (read more)

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28
Apr 11

Meteors from Halley's Comet

Source: NASA News


Source: The Cosmo News

Mark your calendar. On May 6th, Earth will pass through a stream of debris from Halley's comet, producing a mild but beautiful meteor shower known as the "eta Aquarids." (read more)

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28
Apr 11

Moon Zoo - A fantastic online tool for MoonWalkers


A sinuous channel on the Moon. Credit: Moon Zoo.

We present you a new online tool for astronomy education (and more). As everybody knows Zooniverse has been releasing a lot of software tools that can be used by everybody and that might help develop student awareness to astronomy issues and also help you develop new projects with your students. They have now released Moon Zoo a new tool that you can use.

The aim of Moon Zoo is to provide detailed crater counts for as much of the Moon's surface as possible. Unlike here on Earth where weather quickly erodes any signs of all but the most recent impacts, craters on the lunar surface stay almost until eternity. That means that the number of craters on a particular piece of the surface tells us how old it is. This technique is used all over the Solar System, but the Moon is particularly important because we have ground truth — samples brought back by the Apollo missions — which allow us to calibrate our estimates. Planetary scientists have always carried out this kind of analysis on large scales, but with your help and the fabulous LRO images then we should be able to uncover the finer details of the Moon's history.

Craters can tell us more than just the history of the lunar surface though. In particular, you're asked in Moon Zoo to look for craters with boulders around the rim. Boulders are a sign that the impact was powerful enough that it excavated rock from beneath the regolith (the lunar 'soil') and so by keeping an eye out for these we can begin to map the depth of the regolith across the surface of the Moon.

The Moon is perhaps the most familiar object in the night sky, but it still has its mysteries. Following the excitement of the Apollo Moon landings in the 1960s and 1970s, a new flotilla of spacecraft is exploring the Earth's nearest neighbour. The images from NASA's Lunar Reconnaissance Orbiter which you're invited to explore with Moon Zoo show the lunar surface in remarkable detail, including features as small as 50 cm (about one and a half feet) across.

LRO is a remarkable spacecraft, the product of years of hard work by an enormous team of scientists and engineers who made the mission possible. It carries, amongst other instruments, an incredible camera,  LROC . LROC is actually three cameras — two Narrow Angle Cameras which supply Moon Zoo images, and a Wide Angle Camera. Data from the first six months of the mission have been released by the LROC team through the Planetary Data System (PDS), but the project promises more.

Link:
Moon Zoo site

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27
Apr 11

Profiling Polar Craters with the Mercury Laser Altimeter

Source: MESSENGER Mission


.MLA’s first measurements from Mercury orbit. Credits: MESSENGER.

MESSENGER’s Mercury Laser Altimeter (MLA) will measure the topography or surface relief of the northern hemisphere of Mercury. That data will be used to create topographic maps, which will help characterize the geologic history of the planet. One of the most important tasks for MLA is to measure the depths of craters that are near Mercury’s north pole. In the latest “Science Highlights from Mercury’s Orbit,” MESSENGER’s Geophysics discipline group explains why.(read more)

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27
Apr 11

Andromeda’s coat of many colours

Source: ESA


Credit: ESA.

ESA’s fleet of space telescopes has captured the nearby Andromeda Galaxy, also known as M31, in different wavelengths. Most of these wavelengths are invisible to the eye and each shows a different aspect of the galaxy’s nature.(read more)

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26
Apr 11

Navigation by satellite using EGNOS

Source: ESA EuroNews

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25
Apr 11

Mars Reconnaissance Orbiter reveals dramatic changes in Mars' atmosphere

Source: NASA News


Thickness Map of Buried Carbon-Dioxide Deposit.
Image credits: NASA/JPL-Caltech/Sapienza University of Rome/Southwest Research Institute.

 

NASA's Mars Reconnaissance Orbiter (MRO) has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies. This process can affect the stability of liquid water if it exists on the Martian surface and increase the frequency and severity of Martian dust storms.

Researchers using MRO's ground-penetrating radar identified a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole. The scientists suspect that much of this carbon dioxide enters the planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. The findings are published in a report in the journal Science.

The newly found deposit has a volume similar to Lake Superior's nearly 3,000 cubic miles. The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere. Collapse pits caused by dry ice sublimation and other clues suggest the deposit is in a dissipating phase, adding gas to the atmosphere each year. Mars' atmosphere is about 95 percent carbon dioxide, in contrast to Earth's much thicker atmosphere, which is less than .04 percent carbon dioxide. (read more)

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25
Apr 11

Citizen Scientists Making Incredible Discoveries

Source: NASA Science News


Voorwerp floats near a spiral galaxy. Credit: NASA/ESA Hubble Space Telescope

People across the globe are working together thanks to Zooniverse to help scientists analyze data from NASA and ESA spacecraft, and they're making some surprising discoveries.(read more)

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24
Apr 11

Early European astronomers determined Easter dates

Source: ESA

How do they know it’s Easter? Ever wondered how the exact dates of the Easter break are chosen? Easter Sunday can fall anytime between 22 March and 25 April and, thanks to European observations of the Sun that go back many centuries, the exact date can be predicted as far ahead as 4099 AD.(read source)

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23
Apr 11

Ariane 5’s second launch of 2011

Source: ESA News

Last night, an Ariane 5 launcher lifted off from Europe’s Spaceport in French Guiana on its mission to place two telecommunications satellites, Yahsat Y1A and Intelsat New Dawn, into their planned transfer orbits. Flight VA201 was the second Ariane 5 launch of 2011. (read more)

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22
Apr 11

NASA's Hubble Celebrates 21st Anniversary with 'Rose' of Galaxies

Sources: NASA/HST and ESA Hubble Information Centre


Arp 273. Image credits:NASA, ESA and the Hubble Heritage Team (STScI/AURA)

To celebrate the 21st anniversary of the Hubble Space Telescope's deployment into space, astronomers at the Space Telescope Science Institute in Baltimore, Md., pointed Hubble's eye at an especially photogenic pair of interacting galaxies called Arp 273.(read more)

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21
Apr 11

Cassini probe sees electric link between Saturn and one of its moons

Source: NASA News


Artist's concept of the magnetic connection between Saturn and its moon Enceladus. Image credit: NASA/JPL/JHUAPL/University of Colorado/Central Arizona College/SSI

NASA is releasing the first images and sounds of an electrical connection between Saturn and one of its moons. The data collected by the agency's Cassini spacecraft enable scientists to improve their understanding of the complex web of interaction between the planet and its numerous moons. The results of the data analysis are published in the journals Nature and Geophysical Research Letters.

Scientists previously theorized an electrical circuit should exist at Saturn. After analyzing data that Cassini collected in 2008, scientists saw a glowing patch of ultraviolet light emissions near Saturn's north pole that marked the presence of  a circuit, even though the moon is 150,000 miles (240,000 kilometers) away from the planet.

The patch occurs at the end of a magnetic field line connecting Saturn and its moon Enceladus. The area, known as an auroral footprint, is the spot where energetic electrons dive into the planet's atmosphere, following magnetic field lines that arc between the planet's north and south polar regions. (read more)

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20
Apr 11

NASA Kepler Reaching into the Stars

Source: Kepler Mission


Artist's rendering comparing the size and color of the stars in the triple-eclipsing system HD 181068.
Image credit: NASA/KASC

We are entering a golden era for "stellar physics" – a term coined to describe research about the formation, evolution, interior and the atmospheres of stars. Thanks to a partnership forged among stellar astrophysics, scientists and NASA’s Kepler Mission, a goldmine of data is now available to support the world's efforts to detect planets in the habitable zone around other stars.(read more)

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20
Apr 11

A Disturbed Galactic Duo

Source: ESO Photo Release eso1114


The disturbed galactic duo NGC 3169 and NGC 3166. Credit: ESO/Igor Chekalin.

The galaxies in this cosmic pairing, captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, display some curious features, demonstrating that each member of the duo is close enough to feel the distorting gravitational influence of the other. The gravitational tug of war has warped the spiral shape of one galaxy, NGC 3169, and fragmented the dust lanes in its companion NGC 3166. Meanwhile, a third, smaller galaxy to the lower right, NGC 3165, has a front-row seat to the gravitational twisting and pulling of its bigger neighbours. (read source)

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19
Apr 11

Mercury’s Exosphere: A Brief Overview

Source: MESSENGER Mission

One of the primary science goals of MESSENGER is to study Mercury’s very thin atmosphere, or exosphere. Although observations of the exosphere from orbit have begun, these data must be carefully calibrated, and analysis is still underway. In the meantime, Messenger Mission has launched a web primer on Mercury’s exosphere: what it is, how we observe it, and why it is important. (read more)

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19
Apr 11

Effect of solar eclipse on microbes

Source: Shriyan A, Bhat AM, Nayak N. Effect of solar eclipse on microbes. J Pharm Bioall Sci [serial online] 2011 [cited 2011 Apr 19];3:154-7. Available from: http://www.jpbsonline.org/text.asp?2011/3/1/154/76498

A study about the effect of solar eclipses took place in India on 15 th January, 2010. It was a total eclipse in some parts of the country, while it was a partial eclipse in other parts. Since microorganisms play an important role in various phenomena on Earth, the study was undertaken to know the influence of solar eclipse on nature indirectly, by analyzing certain genotypic and phenotypic variations in prokaryotes and eukaryotes. Since yeast have similar gene expression as that of human beings, investigations were pursued on Candida albicans as well as the study of the effect of solar eclipse on cultures of Staphylococcus aureus, Klebsiella species, Escherichia coli, and C. albicans that were performed in laboratory.

There was significant change observed during exposure to normal sunlight and eclipse phase. Bacterial colonies showed difference in morphology on smear examination and sensitivity pattern during this study. One fungal species and three bacterial isolates were studied and changes were recorded. Fungal species showed a definite change in their morphology on exposure to sunlight during eclipse observed by stained smear examination from broth, plate, and slant. This study concludes that blocking of the sun rays during eclipse does not harm prokaryotes and eukaryotes, instead promoted the progeny of predators in the race of better acclimatization and survival in the natural and changing environmental conditions.(read more)

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19
Apr 11

ESA–NASA collaboration furthers sea-ice research

Source: ESA News

A carefully executed operation to validate data from CryoSat has shown what can be accomplished when ESA, NASA and others join forces to further our understanding of how the fragile polar environment is responding to climate change. (read more)

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18
Apr 11

Here comes the 2011 Eratosthenes Project campaign

Once again in 2011 the EAAE is proud to announce the opening of the campaign to reproduce the Eratosthenes Experiment at a global scale. Following the 2010 campaign's success next this activity will be repeated at the next European Summer Solstice on 21st of June 2011.

Every school in Europe is invited to participate in this global experience in order to measure the Earth circumference. With the only help of the shadow projected by a stick, the participating students will be able to repeat the Erastothenes calculation. Moreover, a video conference will allow all participants to see how the activity is performed in the Bibliotheca of Alexandria, the mythic place where this measure was done by the greek mathematician more than 2000 years ago. All information concerning the event will be held on http://www.eaae-astronomy.org.

A screenshot of the project's webpage.

Materials that will help the schools to reproduce the Eratosthenes Experiment locally where created and are also available on the website as well as calculators to help schools confirm their calculations based on their measurements.These calculators can also be used by small children school to make the calculations that the children cannot perform because the don't have the mathematical skills to do them.

The project intends to allow schools to reproduce the Eartothenes Experiment locally.

 

The Eratosthenes website also has links to several complementary Didactical Materials that can be used by teachers when preparing this project or for many other purposes. EAAE members, Anna Artigas and Guido Robotti, will coordinate the 2011 campaign of the project.

Links:
The EAAE Eratosthenes Project

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16
Apr 11

Earth from Space: Dust and plankton

Source: ESA

Envisat captures dust and sand from the Algerian Sahara Desert, located in northern Africa, blowing west across the Atlantic Ocean. Sandstorms are very common over the Sahara, and large concentrations of the dust can be found in the tropical Atlantic and the Caribbean. The dust contains many nutrients, including nitrogen, phosphorus and iron, which act as a fertiliser and stimulate the production of massive plankton blooms. In this image, plankton blooms are visible in the Atlantic as blue and green swirls.

Although some types of plankton are individually microscopic, the chlorophyll they use for photosynthesis collectively tints the colour of the surrounding ocean waters. This allows dedicated 'ocean colour' satellite sensors, such as Envisat's Medium Resolution Imaging Spectrometer (MERIS), to detect them from space. MERIS acquired this image on 8 April at a resolution of 300 m. (read more)

 

Image credit: ESA

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