over a year ago i was blogging about Planck and how all astrophysicists and cosmologists were overwhelmingly excited about its launch... and now, finally my first news story about this brand-new observatory is online!
there's no science yet - just a pretty picture... super pretty actually! or better, super cool :-)
Planck all-sky image depicts galactic mist over the cosmic background
An all-sky image from Planck's recently completed first survey highlights the two major emission sources in the microwave sky: the cosmic background and the Milky Way. The relic radiation coming from the very early Universe is, to a large extent, masked by intervening astronomical sources, in particular by our own Galaxy's diffuse emission. Thanks to Planck's nine frequency channels, and to sophisticated image analysis techniques, it is possible to separate these two contributions into distinct scientific products that are of immense value for cosmologists and astrophysicists, alike. More...
Image Credit: ESA, HFI and LFI consortia.
Monday, 5 July 2010
Friday, 2 July 2010
Just one step away
finally, after an incubation of several (!) months, the article I wrote with a colleague during my internship at ESO has been published on Science in School! it's about ALMA, a huge radiotelescope that is currently being built in the desert of northern Chile...
...and it's supposed to be read by young kids in their last years of school, so we tried to make it catchy and pedagogic at the same time — tough task, hope it works :-)
The ALMA Observatory: the sky is only one step away
Imagine hiking in the Atacama region, high in the Andes of northern Chile, one of the driest and remotest spots on Earth. At altitudes of 5000 m and higher, life is not easy here: the atmospheric pressure is much lower than at sea level, and oxygen is scarce.
The landscape, dominated by large volcanoes and other mountain peaks, occasionally decorated by salt flats and picturesque formations of ice and snow, hardly resembles a typical view of our planet. Then, in the midst of this arid and abandoned region, you become aware of a gigantic construction — could those be huge satellite dishes?
[...]
Read the full text on the website of Science in School.
In the image, an ALMA antenna on the Chajnantor plateau, in northern Chile. Image credits: ALMA (ESO/NAOJ/NRAO)
...and it's supposed to be read by young kids in their last years of school, so we tried to make it catchy and pedagogic at the same time — tough task, hope it works :-)
The ALMA Observatory: the sky is only one step away
Imagine hiking in the Atacama region, high in the Andes of northern Chile, one of the driest and remotest spots on Earth. At altitudes of 5000 m and higher, life is not easy here: the atmospheric pressure is much lower than at sea level, and oxygen is scarce.
The landscape, dominated by large volcanoes and other mountain peaks, occasionally decorated by salt flats and picturesque formations of ice and snow, hardly resembles a typical view of our planet. Then, in the midst of this arid and abandoned region, you become aware of a gigantic construction — could those be huge satellite dishes?
[...]
Read the full text on the website of Science in School.
In the image, an ALMA antenna on the Chajnantor plateau, in northern Chile. Image credits: ALMA (ESO/NAOJ/NRAO)
The electromagnetic spectrum - reprise
I am writing this post following a thread that I started over a year ago about a topic that I am very fond of: the electromagnetic spectrum, which I believe is (unfortunately!) not a widely understood concept. ever since I wrote that post, I wanted to spend a few words and explain what all the fuzz is about - but of course I never had time for that...
then, a few months ago, I had the chance to write a story about ALMA, a world-class radio telescope, and since the story was supposed to be addressed to school kids, I thought - what a cool opportunity to try and explain this topic once and for all... so I convinced the editors of Science in School to have a separate box about it. space on the magazine is always scarce, but I tried to do my best - in less than 200 words!!
Detecting astronomical objects along the electromagnetic spectrum
Visible light is just a small part of the whole spectrum of electromagnetic radiation. The different parts of the spectrum, or spectral bands, are, in order of decreasing wavelength and increasing frequency: radio waves (including microwaves and (sub)millimetre radiation), infrared, visible, ultraviolet, X-rays and gamma rays.
Because different physical processes in the Universe emit light at different wavelengths, each class of objects in the Universe shines most brightly in one or several particular spectral bands. Modern astronomers often try to target many bands, using different telescopes, since each set of observations provides a complementary piece of the puzzle; this approach is called multi-wavelength astronomy.
However, Earth’s atmosphere complicates matters, because it absorbs most of the radiation. Although this protects us, it makes life difficult for astronomers: only a tiny fraction of the electromagnetic spectrum is observable from the ground, and often in these cases, the quality of the observations strongly depends on the geographical site. This is why choosing an excellent site such as Chajnantor for ALMA is so important. In other spectral bands, especially at very short wavelengths, astronomers need telescopes aboard satellites in orbit around our planet, outside the obscuring layer of the atmosphere.
Image credits: ESA/Hubble/F.Granato
then, a few months ago, I had the chance to write a story about ALMA, a world-class radio telescope, and since the story was supposed to be addressed to school kids, I thought - what a cool opportunity to try and explain this topic once and for all... so I convinced the editors of Science in School to have a separate box about it. space on the magazine is always scarce, but I tried to do my best - in less than 200 words!!
Detecting astronomical objects along the electromagnetic spectrum
Visible light is just a small part of the whole spectrum of electromagnetic radiation. The different parts of the spectrum, or spectral bands, are, in order of decreasing wavelength and increasing frequency: radio waves (including microwaves and (sub)millimetre radiation), infrared, visible, ultraviolet, X-rays and gamma rays.
Because different physical processes in the Universe emit light at different wavelengths, each class of objects in the Universe shines most brightly in one or several particular spectral bands. Modern astronomers often try to target many bands, using different telescopes, since each set of observations provides a complementary piece of the puzzle; this approach is called multi-wavelength astronomy.
However, Earth’s atmosphere complicates matters, because it absorbs most of the radiation. Although this protects us, it makes life difficult for astronomers: only a tiny fraction of the electromagnetic spectrum is observable from the ground, and often in these cases, the quality of the observations strongly depends on the geographical site. This is why choosing an excellent site such as Chajnantor for ALMA is so important. In other spectral bands, especially at very short wavelengths, astronomers need telescopes aboard satellites in orbit around our planet, outside the obscuring layer of the atmosphere.
---
The image above displays the atmospheric opacity - the level of the brown curve represents how opaque the atmosphere is at the given wavelength. The major windows are at visible wavelengths (marked by the rainbow) and at radio wavelengths from about 1 mm to 10 m. Observations at wavelengths where the atmosphere is opaque require space telescopes.Image credits: ESA/Hubble/F.Granato
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