Oferte Emag

Baby stars in the Rosette cloud

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Herschel’s latest image reveals the formation of previously unseen large stars, each one up to ten times the mass of our Sun. These are the stars that will influence where and how the next generation of stars are formed. The image is a new release of ‘OSHI’, ESA’s Online Showcase of Herschel Images.

The Rosette Nebula resides some 5,000 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each colour represents a different temperature of dust, from –263ºC (only 10ºC above absolute zero) in the red emission to –233ºC in the blue.

The bright smudges are dusty cocoons hiding massive protostars. These will eventually become stars containing around ten times the mass of the Sun. The small spots near the centre and in the redder regions of the image are lower mass protostars, similar in mass to the Sun.

ESA’s Herschel space observatory collects the infrared light [...]

Rosetta sees a living planet

Rosetta sees a living planet

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Images and data taken just before closest approach were downloaded this morning, and they show the lights of North America in the night and a glowing Southern Hemisphere.

The image above shows the illuminated crescent of Earth showing part of South America and Antarctica. This OSIRIS image was acquired with the the narrow-angle camera from a distance of 350 000 km at 22:28 UTC last night. The resolution is 6.5 km/pixel.

A cloud-covered North America was captured at 14:03 UTC (15:03 CET), when Rosetta was at a distance of approximately 224 000 km from Earth’s centre by Rosetta’s navigation camera (navcam).

The navcam is used for precise determination of the orbit and optical visualisation. The output of the camera tells you where the centre of the object that is in the centre of the field of view is – it also gives physical parameters of the object.

The photos were taken to test the camera’s operation with a large physical obejct. Previously, Steins was also imaged, but it is rather small (about 5 km across). Next year, the camera will be used to view Lutetia, which is much larger (about 95 km across). In the camera field of [...]

Rosetta starts tracking asteroid Steins


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Heading toward its first target-asteroid, (2867) Steins, ESA’s Rosetta spacecraft has started using its cameras to visually track the asteroid and eventually determine its orbit with more accuracy.

Rosetta started the optical navigation campaign on 4 August 2008, at a distance of about 24 million km from Steins; the campaign will continue until 4 September, when the spacecraft will be approximately 950 000 km from the asteroid.

“The orbit of Steins, with which Rosetta will rendezvous on 5 September, closing to a distance of 800 km, is only known thanks to ground observations, but not yet with the accuracy we would like for the close fly-by,” said Gerhard Schwehm, Rosetta Mission Manager based at ESA’s European Space Astronomy Centre (ESAC), near Madrid, Spain.

“We will be able to use the first data set for the trajectory correction manoeuvre planned for mid-August.” Optical tracking to better understand Steins’ orbit

The purpose of the tracking campaign is to reduce the error in our knowledge of Steins’ orbit from about 100 km to only within 2 km (in the direction perpendicular to the flight direction of the asteroid, called ‘cross-track’), so as to allow Rosetta an optimal approach to this celestial [...]

Rosetta – OSIRIS view of Earth by night


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This striking composite of Earth by night shows the illuminated crescent over Antarctica and cities of the northern hemisphere. The images were acquired with the OSIRIS Wide Angle Camera (WAC) during Rosetta’s second Earth swing-by on 13 November.

This image showing islands of light created by human habitation was taken with the OSIRIS WAC at 19:45 CET, about 2 hours before the closest approach of the spacecraft to Earth. At the time, Rosetta was about 80 000 km above the Indian Ocean where the local time approached midnight (the angle between Sun, Earth and Rosetta was about 160°). The image was taken with a five-second exposure of the WAC with the red filter.

This image showing Earth’s illuminated crescent was taken with the WAC at 20:05 CET as Rosetta was about 75 000 km from Earth. The crescent seen is around Antarctica. The image is a colour composite combining images obtained at various wavelengths.

Stunning view of Rosetta skimming past Mars


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This stunning view, showing portions of the Rosetta spacecraft with Mars in the background, was taken by the Rosetta Lander Imaging System (CIVA) on board Rosetta’s Philae lander just four minutes before the spacecraft reached closest approach to the Red Planet earlier this morning.

While the Rosetta orbiter instruments were switched off as planned during several hours around closest approach, which occurred at 03:15 CET today, some of the lander instruments were operational and collected data from Mars.

This incredible CIVA image was taken about 1000 kilometres from the planet’s surface. A portion of the spacecraft and one of its solar arrays are visible in nice detail. Beneath, an area close to the Syrtis region is visible on the planet’s disk.

Philae lander in first autonomous operation

This is the first time that the Philae lander operated in a totally autonomous mode, completely relying on the power of its own batteries. This will be the case when the lander will have touched down on comet 67P Churyumov-Gerasimenko in 2014 and will have to perform its scientific measurements independently from the Rosetta orbiter.

A sequence of observations from today’s Mars close approach were run successfully, providing an important test [...]

Challenges of landing on alien worlds


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Three ESA missions are due to send down robotic ‘spaceprobes’ when they arrive at their alien destinations. Since these craft will be going where no one has gone before, how can scientists be sure what it will be like down there? How do you ensure that your spaceprobe is prepared for anything?

Experts take every precaution to ensure that these probes will not burn up entering an alien atmosphere, or meet a spectacular, untimely end via a crash landing on inhospitable terrain. These probes expect the worst.

For example, the Huygens probe, which is currently on its journey to Titan, Saturn’s largest moon, on-board the Cassini spacecraft, can withstand temperatures of up to 18 000°C in the shockwave in front of the heat shield. This is about three times the Sun’s surface temperature. Why? The heat generated as Huygens travels through Titan’s thick atmosphere will be immense.

A typical weather update

Dust storms such as these on Mars complicate landings

Jean-Pierre Lebreton, Huygens Project Scientist, says “Things will get interesting once Cassini draws close to Saturn. We’ll get the best views of Saturn and Titan that we ever had. We’ll also observe Titan to verify that our models [...]