相关论文: Detecting 3D vegetation structure with the Galileo…
Earth's deciduous plants have a sharp order-of-magnitude increase in leaf reflectance between approximately 700 and 750 nm wavelength. This strong reflectance of Earth's vegetation suggests that surface biosignatures with sharp spectral…
The vegetation's ``red edge'', an intensity bump in the Earth's spectrum near 700 $nm$ when sunlight is reflected from greenery, is often suggested as a tool in the search for life in terrestrial-like extrasolar planets. Here, through…
When Carl Sagan observed the Earth during a Gallileo fly-by in 1993, he found a widely distributed surface pigment with a sharp reflection edge in the red part of the spectrum, which, together with the abundance of gaseous oxygen and…
The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet's atmosphere ($O_2$, $O_3$, $CO_2$ etc.)…
We analyse the detectability of vegetation on a global scale on Earth's surface. Considering its specific reflectance spectrum showing a sharp edge around 700 nm, vegetation can be considered as a potential global biomarker. This work,…
Can multicellular life be distinguished from single cellular life on an exoplanet? We hypothesize that abundant upright photosynthetic multicellular life (trees) will cast shadows at high sun angles that will distinguish them from single…
We report spectroscopic observations (400 to 800nm, R = approx 100) of Earthshine in June, July and October 2001 from which normalised Earth albedo spectra have been derived. The resulting spectra clearly show the blue colour of the Earth…
The detection and characterization of potentially habitable exoplanets is one of the chief goals of astrophysics for the coming decades. Imaging in reflected light is well suited for characterizing Earth-like planets, as much can be learned…
The so-called Vegetation Red-Edge (VRE), a sharp increase in the reflectance around $700 nm$, is a characteristic of vegetation spectra, and can therefore be used as a biomarker if it can be detected in an unresolved extrasolar Earth-like…
The search for Earth-like extrasolar planets is in part motivated by the potential detection of spectroscopic biomarkers. Spectroscopic biomarkers are spectral features that are either consistent with life, indicative of habitability, or…
The high reflection of land vegetation in the near-infrared, the vegetation red edge (VRE), is often cited as a spectral biosignature for surface vegetation on exoplanets. The VRE is only a few percent change in reflectivity for a…
The Earth viewed from outside the Solar system would be identified merely like a pale blue dot, as coined by Carl Sagan. In order to detect possible signatures of the presence of life on a second earth among several terrestrial planets…
Reflection spectroscopy holds great promise for characterizing the atmospheres and surfaces of potentially habitable terrestrial exoplanets. The surface of the modern Earth exhibits a sharp albedo change near 750 nm caused by vegetation -…
Vegetation can modify the planetary surface albedo via the Charney mechanism, as plants are usually darker than the bare surface of the continents. We updated ESTM (Earth-like Surface Temperature Model) to incorporate the presence,…
Future telescopes will characterize rocky exoplanets in reflected light, revealing their albedo, which depends on surface, cloud, and atmospheric properties. Identifying these features is crucial for assessing habitability. We present…
Understanding the spectral and photometric variability of the Earth and the rest of the solar system planets has become of the utmost importance for the future characterization of rocky exoplanets. As this is not only interesting at present…
Soil organic carbon (SOC) is a critical indicator of soil health, but its accurate estimation from satellite imagery is hindered in vegetated regions due to spectral contamination from plant cover, which obscures soil reflectance and…
This study explores the potential to enhance the reflectance of solar insolation by the human settlement and grassland components of the Earth's terrestrial surface as a climate change mitigation measure. Preliminary estimates derived using…
The Galileo spacecraft had distant encounters with Earth in 1990 and 1992. Limited Solid State Imager (SSI) data acquired during these encounters has been previously presented, but the majority of the data from these Earth flybys have not…
Due to climatic changes, excessive grazing, and deforestation, semi-arid and arid ecosystems are vulnerable to desertification and land degradation. As aridity increases, vegetation cover often self-organizes into spatial patterns before…