Friday, 27 April 2007

Astronomers Find First Earth-like Planet in Habitable Zone

The new planet known as Gliese 581 c (L) orbiting a red dwarf star
Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.
This exoplanet - as astronomers call planets around a star other than the Sun - is the smallest ever found up to now and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581, is smaller and colder than the Sun - and thus less luminous - the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid! The planet's name is Gliese 581 c.
The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another 'Trio of Neptunes'
The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs (video).

Photographs from The Met

See one hundred of the best photograph collection works of art from The Metropolitan Museum online.

Charles Nègre (French, 1820–1880). The Refectory of the Imperial Asylum at Vincennes, 1858–59
Gathered in the light-drenched refectory of a newly constructed convalescent hospital on the outskirts of Paris, patients and staff alike turned their eyes and attention to the man with the enormous camera at one end of the room, Charles Nègre. The resulting image, here in a rare unmounted and unretouched proof print from the artist's studio, is the largest and most engaging in a series of photographs that Nègre was commissioned to make as documentation and celebration of the Imperial Asylum at Vincennes. The hospital was established by Emperor Napoléon III to provide those injured on the construction site or in the factory—"the worker's true field of honor," in the words of one of Napoléon's ministers—with care comparable to that given to the nation's military veterans.
Trained as a painter in the same studio as Roger Fenton and Gustave Le Gray, Nègre was one of the era's most skilled photographers of architecture, possessing a particular sensitivity to the ways in which light and shadow animate the surfaces of centuries-old monuments. Here, he seized upon the streaming sunlight as a vehicle to enliven the structure and texture of his picture and to suggest enhanced activity and health in the hospital inhabitants.

Saturday, 14 April 2007

Interactive Poster/Video of The Macaque Genome

Special interactive version of the Macaque Genome poster, with large-format images, text, and video interviews on the broad biomedical and evolutionary themes that the genome raises (view).
You can also read the Lessons from Comparative Genomic (read).

Thursday, 5 April 2007


Worldmapper is a collection of world maps, where territories are re-sized on each map according to the subject of interest.
There are 366 maps, also available as PDF posters.

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