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Biosignatures as revealed by spectropolarimetry of Earthshine

Overview of attention for article published in Nature, February 2012
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About this Attention Score

  • In the top 5% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (99th percentile)
  • Good Attention Score compared to outputs of the same age and source (75th percentile)

Mentioned by

4 news outlets
7 blogs
17 tweeters
2 Facebook pages
2 Google+ users


63 Dimensions

Readers on

102 Mendeley
1 CiteULike
Biosignatures as revealed by spectropolarimetry of Earthshine
Published in
Nature, February 2012
DOI 10.1038/nature10778
Pubmed ID

Michael F. Sterzik, Stefano Bagnulo, Enric Palle


Low-resolution intensity spectra of Earth's atmosphere obtained from space reveal strong signatures of life ('biosignatures'), such as molecular oxygen and methane with abundances far from chemical equilibrium, as well as the presence of a 'red edge' (a sharp increase of albedo for wavelengths longer than 700 nm) caused by surface vegetation. Light passing through the atmosphere is strongly linearly polarized by scattering (from air molecules, aerosols and cloud particles) and by reflection (from oceans and land). Spectropolarimetric observations of local patches of Earth's sky light from the ground contain signatures of oxygen, ozone and water, and are used to characterize the properties of clouds and aerosols. When applied to exoplanets, ground-based spectropolarimetry can better constrain properties of atmospheres and surfaces than can standard intensity spectroscopy. Here we report disk-integrated linear polarization spectra of Earthshine, which is sunlight that has been first reflected by Earth and then reflected back to Earth by the Moon. The observations allow us to determine the fractional contribution of clouds and ocean surface, and are sensitive to visible areas of vegetation as small as 10 per cent. They represent a benchmark for the diagnostics of the atmospheric composition, mean cloud height and surfaces of exoplanets.

Twitter Demographics

The data shown below were collected from the profiles of 17 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 102 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
United States 3 3%
Italy 2 2%
Brazil 1 <1%
Australia 1 <1%
United Kingdom 1 <1%
Chile 1 <1%
Japan 1 <1%
Norway 1 <1%
Spain 1 <1%
Other 2 2%
Unknown 88 86%

Demographic breakdown

Readers by professional status Count As %
Student > Ph. D. Student 27 26%
Researcher 25 25%
Student > Master 12 12%
Professor 8 8%
Other 6 6%
Other 24 24%
Readers by discipline Count As %
Physics and Astronomy 38 37%
Earth and Planetary Sciences 26 25%
Unspecified 10 10%
Agricultural and Biological Sciences 9 9%
Environmental Science 4 4%
Other 15 15%

Attention Score in Context

This research output has an Altmetric Attention Score of 104. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 30 September 2018.
All research outputs
of 12,728,337 outputs
Outputs from Nature
of 66,131 outputs
Outputs of similar age
of 126,596 outputs
Outputs of similar age from Nature
of 985 outputs
Altmetric has tracked 12,728,337 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 98th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 66,131 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 73.7. This one has done well, scoring higher than 83% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 126,596 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 99% of its contemporaries.
We're also able to compare this research output to 985 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 75% of its contemporaries.