Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An extraterrestrial's view of the Earth

27.12.2007
Searchers for habitable planets in the Milky Way have found a new ally.According to research led by astronomers from the Instituto de Astrofisica de Canarias (IAC), clouds can provide enough information to determine the period of rotation of a planet and deduce the variability of its atmosphere.

Owing to the role played by clouds, which are so commonplace on Earth but unique in the Solar System for their dynamism, it could suffice scientists to analyse the brightness of a planet to ascertain the length of its day and determine whether or not there is water on its surface.

From data obtained over two decades (1984-2005) by a network of meteorological satellites from all over the world, astronomers Enric Pallé, Pilar Monañés-Rodríguez and Manuel Vázquez from the IAC, together with Eric Ford from the University of Florida and Sara Seager of the Massachusetts Institute of Technology, have produced a computer-generated model of the Earth's brightness. Results have shown that, if observed as a point source, such as an extraterrestrial observer would view it, the Earth's cloud mass would follow a repetitive pattern with a certain frequency.

"The trick lies in interpreting the movement of the Earth's surface and the clouds as periodical signals, just as if we were to observe the spots on a spinning ball appearing and disappearing", explains Enric Pallé, first author of an article to be published next month in the American Astrophysical Journal.

From the patterns registered over several weeks of tracking, it is ossible to deduce the planet's rotational period since "on a global scale clouds aren't as random and chaotic as is generally believed, but instead follow a pattern marked by continental orography and oceanic currents".

Eric Ford, coauthor of the paper and astrophysicist at the University of Florida, ventures the thought that, should some extraterrestrial astrophysicists be looking for life beyond their own planet, "they'd only be able to see Earth as a faint dot because of the distance that separates us, but that could be enough for them to identify it as a planet that has clouds and oceans of liquid water". The existence of a liquid medium such as water is considered a necessary condition for life.

And it's only Earth among all the planets in the Solar System that shows persistent atmospheric variations: Venus is always covered in cloud, whereas on Mars clear skies predominate. According to Pallé, "on Earth the water is cyclicly transformed from ice to liquid to vapour owing to temperature and pressure conditions on its surface".

The presence of clouds produces a slight variability in the Earth's apparent rotation. This variability is an indication of climatic patterns, ofthe probable presence of water and therefore of conditions suitable for life. In this way, those planets with a "flat encephalogram", that is, with no visible cloud dynamics, have a lower probability of being habitable.

The researchers hold that the identification of the rotational period of an extrasolar planet will help us understand the mechanism that govern the formation of planetary systems. It will also aid in the design of a new generation of space telescopes to study earthlike planets with higher precision.

"It's possible that in a few decades we'll have a telescope capable of visualising some of the details of the atmosphere and surface of an earthlike planet. We will then be in a position to compare the simulations of this study with direct observations. For the moment, we are still hungry for photons", says Pallé. The hunt for photons will be boosted in 2008 by the Gran Telescopio CANARIAS (GTC), which, with its 10.4 metre mirror, is the largest in the world, and which is now being commissioned with the collaborative partnership of the University of Florida and Mexico.

Nadjejda Vicente Cabañas | alfa
Further information:
http://www.iac.es/divulgacion.php?op1=16&id=509&lang=en

More articles from Physics and Astronomy:

nachricht ALMA discovers aluminum around young star
17.05.2019 | National Institutes of Natural Sciences

nachricht JQI researchers shed new light on atomic 'wave function'
17.05.2019 | National Institute of Standards and Technology (NIST)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

Im Focus: Recording embryonic development

Scientists develop a molecular recording tool that enables in vivo lineage tracing of embryonic cells

The beginning of new life starts with a fascinating process: A single cell gives rise to progenitor cells that eventually differentiate into the three germ...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Discovering unusual structures from exception using big data and machine learning techniques

17.05.2019 | Materials Sciences

ALMA discovers aluminum around young star

17.05.2019 | Physics and Astronomy

A new iron-based superconductor stabilized by inter-block charger transfer

17.05.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>