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Planck’s new view of the cosmic theatre

Copyright ESA

The first scientific results from ESA’s Planck mission were released at a press briefing today in Paris. The findings focus on the coldest objects in the Universe, from within our Galaxy to the distant reaches of space.

If William Shakespeare were an astronomer living today, he might write that “All the Universe is a stage, and all the galaxies merely players.” Planck is bringing us new views of both the stage and players, revealing the drama of the evolution of our Universe.

Following the publication by ESA of the first full-sky Planck image in July last year, today sees the release of the first scientific results from the mission.

These results are being presented by the Planck Collaboration at a major scientific conference in Paris this week, based on 25 papers submitted to the journal Astronomy & Astrophysics.

The basis of many of these results is the Planck mission’s ‘Early Release Compact Source Catalogue’, the equivalent of a cast list.

Drawn from Planck’s continuing survey of the entire sky at millimetre and submillimetre wavelengths, the catalogue contains thousands of very cold, individual sources which the scientific community is now free to explore.

“This is a great [...]

Andromeda’s once and future stars

Copyright ESA

Two ESA observatories have combined forces to show the Andromeda Galaxy in a new light. Herschel sees rings of star formation in this, the most detailed image of the Andromeda Galaxy ever taken at infrared wavelengths, and XMM-Newton shows dying stars shining X-rays into space.

During Christmas 2010, ESA’s Herschel and XMM-Newton space observatories targeted the nearest large spiral galaxy M31. This is a galaxy similar to our own Milky Way – both contain several hundred billion stars. This is the most detailed far-infrared image of the Andromeda Galaxy ever taken and shows clearly that more stars are on their way.

Sensitive to far-infrared light, Herschel sees clouds of cool dust and gas where stars can form. Inside these clouds are many dusty cocoons containing forming stars, each star pulling itself together in a slow gravitational process that can last for hundreds of millions of years. Once a star reaches a high enough density, it will begin to shine at optical wavelengths. It will emerge from its birth cloud and become visible to ordinary telescopes.

Many galaxies are spiral in shape but Andromeda is interesting because it shows a large ring of dust about 75 000 [...]

Flight of the Comet

Copyright NASA

Flight of the Comet

This video clip was compiled from images taken by NASA’s EPOXI mission spacecraft during its flyby of comet Hartley 2 on Nov. 4, 2010. During the encounter, the spacecraft and comet whisked past each other at a speed of 12.3 kilometers per second (27,560 miles per hour). The spacecraft came within about 700 kilometers (435 miles) of the comet’s nucleus at the time of closest approach.

“While future generations should have the opportunity to truly explore comets, this flyby gives us an excellent preview of what they will get to enjoy,” said EPOXI principal investigator Michael A’Hearn of the University of Maryland, College Park. “Hartley 2 exceeded all our expectations in not only scientific value but in its stark majestic beauty.”

The video clip of the flyby is comprised of 40 frames taken from the spacecraft’s Medium-Resolution Instrument during the encounter. The first image was taken at about 37 minutes before the time of closest approach at a distance of about 27,350 kilometers (17,000 miles). The last image was taken 30 minutes after closest approach at a distance of 22,200 kilometers (13,800 miles). The spacecraft was able to image nearly 50 percent of [...]

Survey Suggests Earth-Sized Planets Are Common

Copyright NASA

Nearly one in four stars similar to the sun may host planets as small as Earth, according to a new study funded by NASA and the University of California.

The study is the most extensive and sensitive planetary census of its kind. Astronomers used the W.M. Keck Observatory in Hawaii for five years to search 166 sun-like stars near our solar system for planets of various sizes, ranging from three to 1,000 times the mass of Earth. All of the planets in the study orbit close to their stars. The results show more small planets than large ones, indicating small planets are more prevalent in our Milky Way galaxy.

“We studied planets of many masses — like counting boulders, rocks and pebbles in a canyon — and found more rocks than boulders, and more pebbles than rocks. Our ground-based technology can’t see the grains of sand, the Earth-size planets, but we can estimate their numbers,” said Andrew Howard of the University of California, Berkeley, lead author of the new study. “Earth-size planets in our galaxy are like grains of sand sprinkled on a beach — they are everywhere.”

The study appears in the Oct. 29 issue of [...]

Hubble Captures First Images of Aftermath of Possible Asteroid Collision

Copyright NASA

NASA’s Hubble Space Telescope has captured the first snapshots of a suspected asteroid collision. The images show a bizarre X-shaped object at the head of a comet-like trail of material.

In January, astronomers began using Hubble to track the object for five months. They thought they had witnessed a fresh asteroid collision, but were surprised to learn the collision occurred in early 2009.

“We expected the debris field to expand dramatically, like shrapnel flying from a hand grenade,” said astronomer David Jewitt of the University of California in Los Angeles, who is a leader of the Hubble observations. “But what happened was quite the opposite. We found that the object is expanding very, very slowly.”

The peculiar object, dubbed P/2010 A2, was found cruising around the asteroid belt, a reservoir of millions of rocky bodies between the orbits of Mars and Jupiter. It is estimated modest-sized asteroids smash into each other about once a year. When the objects collide, they inject dust into interplanetary space. But until now, astronomers have relied on models to make predictions about the frequency of these collisions and the amount of dust produced.

Catching colliding asteroids is difficult because large impacts are [...]

Kepler Mission Discovers Two Planets Transiting the Same Star

Copyright NASA

NASA’s Kepler spacecraft has discovered the first confirmed planetary system with more than one planet crossing in front of, or transiting, the same star.

The transit signatures of two distinct planets were seen in the data for the sun-like star designated Kepler-9. The planets were named Kepler-9b and 9c. The discovery incorporates seven months of observations of more than 156,000 stars as part of an ongoing search for Earth-sized planets outside our solar system. The findings will be published in Thursday’s issue of the journal Science.

Kepler’s ultra-precise camera measures tiny decreases in the stars’ brightness that occur when a planet transits them. The size of the planet can be derived from these temporary dips.

The distance of the planet from the star can be calculated by measuring the time between successive dips as the planet orbits the star. Small variations in the regularity of these dips can be used to determine the masses of planets and detect other non-transiting planets in the system.

In June, mission scientists submitted findings for peer review that identified more than 700 planet candidates in the first 43 days of Kepler data. The data included five additional candidate systems that appear [...]

Pulverized Planet Dust May Lie Around Double Stars

Copyright NASA

Tight double-star systems might not be the best places for life to spring up, according to a new study using data from NASA’s Spitzer Space Telescope. The infrared observatory spotted a surprisingly large amount of dust around three mature, close-orbiting star pairs. Where did the dust come from? Astronomers say it might be the aftermath of tremendous planetary collisions.

“This is real-life science fiction,” said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. “Our data tell us that planets in these systems might not be so lucky — collisions could be common. It’s theoretically possible that habitable planets could exist around these types of stars, so if there happened to be any life there, it could be doomed.”

Drake is the principal investigator of the research, published in the Aug.19 issue of the Astrophysical Journal Letters.

The particular class of binary, or double, stars in the study are about as snug as stars get. Named RS Canum Venaticorums, or RS CVns for short, they are separated by only about two million miles (3.2 million kilometers), or two percent of the distance between Earth and our sun. The stellar pairs orbit around each other every few [...]

Perseids Complete 2010 August Light Show

Copyright NASA

The 2010 Perseid meteor shower is drawing to a close after painting brilliant streaks across the August nighttime skies. This year’s shower began around July 17, peaked August 12-13 and will be officially over by August 24.

“The Perseids are a great shower, one I look forward to every year. And this year didn’t disappoint!” said Dr. Bill Cooke, head of NASA’s Meteoroid Environment Office, located at the Marshall Space Flight Center in Huntsville, Ala.

More About the Perseids

The Perseid meteor shower has been observed for at least 2,000 years and is associated with the comet 109P/Swift-Tuttle, which orbits the sun once every 133 years or so. Each year in August, the Earth passes through a cloud of the comet’s debris. These bits of ice and dust travel around 132,000 mph, burning up about 56 miles overhead in the Earth’s atmosphere to create one of the best meteor showers of the year. The shower is called the “Perseids” because the meteors appear to come from the direction of the constellation Perseus.

The Perseids can be of any brightness, but most are as bright as Polaris – the North Star — or brighter. This meteor shower, however, [...]

Planck unveils the Universe – now and then

Copyright ESA

ESA’s Planck mission has delivered its first all-sky image. It not only provides new insight into the way stars and galaxies form but also tells us how the Universe itself came to life after the Big Bang.

“This is the moment that Planck was conceived for,” says ESA Director of Science and Robotic Exploration, David Southwood. “We’re not giving the answer. We are opening the door to an Eldorado where scientists can seek the nuggets that will lead to deeper understanding of how our Universe came to be and how it works now. The image itself and its remarkable quality is a tribute to the engineers who built and have operated Planck. Now the scientific harvest must begin.”

From the closest portions of the Milky Way to the furthest reaches of space and time, the new all-sky Planck image is an extraordinary treasure chest of new data for astronomers.

The main disc of our Galaxy runs across the centre of the image. Immediately striking are the streamers of cold dust reaching above and below the Milky Way. This galactic web is where new stars are being formed, and Planck has found many locations where individual stars [...]

Hubble captures bubbles and baby stars

Copyright ESA The NASA/ESA Hubble Space Telescope captures a complex network of gas clouds and star clusters within our neighbouring galaxy, the Large Magellanic Cloud. This region of energetic star birth is one of the most active in the nearby Universe.

The Large Magellanic Cloud contains many bright bubbles of glowing gas. One of the largest and most spectacular is LHA 120-N 11, from the catalogue compiled in 1956 by the late astronomer and astronaut Karl Henize. It is informally known as N11.

Close up, N11’s billowing pink clouds of glowing gas resemble a puffy swirl of fairground candyfloss. From further away, its distinctive overall shape led some observers to nickname it the Bean Nebula. The dramatic and colourful features in the nebula are the telltale signs of star birth.

N11 is a well-studied region that extends across 1000 light-years. It is the second largest star-forming region within the Large Magellanic Cloud and has produced some of the most massive stars known.

It is the process of star birth that gives N11 its distinctive look. Three successive generations of stars, each of which formed further away from the centre of the nebula than the last, have [...]