skip to main |
skip to sidebar
The heavens are home to an alien world that shines a deep cobalt blue in a solar system far, far away from our own. Astronomers used the ageing Hubble space telescope to determine the true colour of the distant world, the first time such a feat has been achieved for a planet that circles a star other than the sun.
Unlike the pale blue dot that harbours all known life in the cosmos, the "deep blue dot" is an inhospitable gas giant that lies 63 light years from Earth. On HD189733b, as the planet is named, the temperature soars to 1,000C and glassy hail whips through the air on hypersonic winds.
Though the planet is hostile to life as we know it, the same technique could be used to spot potentially habitable worlds, through changes in cloud cover and other features.
Frederic Pont at Exeter University observed the planet before, during, and after it passed behind its star. When the planet was on either side, the telescope collected light from the star along with light reflected from the planet's surface. But as the planet moved behind the star, the light it reflected was blocked out.
Using an instrument onboard the telescope called an imaging spectrograph, Pont noticed that blue light dimmed sharply as the planet passed behind its star, but brightened again when it emerged on the other side. "As far as I am aware, nobody has had actual results on the colour of an exoplanet," Pont said. "Now we can say that this planet is blue."
The deep cobalt colouration is thought to come from a similar process to that which makes Earth look blue from space, namely the scattering of blue light in the atmosphere. On the planet Pont observed, the scattering is probably due to a fine mist of silicate particles that are blown around by 7,000kph winds.
Read the entire article:
http://www.guardian.co.uk/science/2013/jul/11/alien-deep-blue-planet-astronomers
|
[Click here to read the rest of this article...]
Though only about dozen potentially habitable exoplanets have been detected so far, scientists say the universe should be teeming with alien worlds that could support life. The Milky Way alone may host 60 billion such planets around faint red dwarf stars, a new estimate suggests.
Based on data from NASA's planet-hunting Kepler spacecraft, scientists have predicted that there should be one Earth-size planet in the habitable zone of each red dwarf, the most common type of star. But a group of researchers has now doubled that estimate after considering how cloud cover might help an alien planet support life.
"Clouds cause warming, and they cause cooling on Earth," study researcher Dorian Abbot, an assistant professor in geophysical sciences at the University of Chicago, said in a statement. "They reflect sunlight to cool things off, and they absorb infrared radiation from the surface to make a greenhouse effect. That's part of what keeps the planet warm enough to sustain life."
The habitable zone is defined as the region where a planet has the right temperature to keep liquid water on its surface, thought to be a requirement for life as we know it. If a planet is too far from its star, its water freezes; too close, water vaporizes. Since red dwarfs are dimmer and cooler than our sun, their habitable zone is much cozier than our solar system's.
"If you're orbiting around a low-mass or dwarf star, you have to orbit about once a month, once every two months to receive the same amount of sunlight that we receive from the sun," explained another study author, Nicolas Cowan, a postdoctoral fellow at Northwestern University.
Read the entire article:
http://www.space.com/21800-alien-planets-60-billion-habitable-exoplanets.html
|
[Click here to read the rest of this article...]
Extra-terrestrial life may be just around the corner from Earth, in astronomical terms, on one of possibly habitable 4.5 billion planets in the Milky Way, according to a new research.
Stars called red dwarfs may support planets on which life is possible. Six percent of red dwarfs in the galaxy have Earth-sized planets, which could be habitable, astronomers at the Harvard-Smithsonian Center for Astrophysics have estimated.
Red dwarf are the most common stars in the Milky Way, which means that the closest earth like planet could be just 13 light years away, not far in space terms.
Red dwarfs are smaller, cooler and fainter than our Sun and are not visible from Earth to the naked eye.But despite their relative dimness, they make up three out of every four stars in our galaxy, a total of 75 billion.
“We thought we would have to search vast distances to find an earth-like planet. Now we realize another Earth is probably in our own backyard, waiting to be spotted,” said Courtney Dressing, an astronomer who presented the finding at a press conference Wednesday at the Harvard-Smithsonian Center in Massachusetts.
Dressing identified 95 planetary candidates orbiting red dwarf stars. According to the scientists’ estimates, 60 percent of red dwarfs could have planets orbiting them that could be smaller than Neptune.
Most were not quite the right temperature or size to be truly Earth-like, although three of the planets were warm and were approximately Earth-sized. Statistically therefore six percent of red dwarfs could have an Earth-like planet, scientists add.
“We don’t know for sure if life could exist on a planet orbiting a red dwarf, but the findings pique my curiosity and leave me wondering if the cosmic cradles of life are more diverse than we humans have imagined,” said Natalie Batalha, Kelper mission scientist at NASA’s Ames Research Center.
Read the entire article:
http://rt.com/news/red-dwarfs-habitable-planets-685/
|
[Click here to read the rest of this article...]
The planet lies in what they describe as a 'habitable zone', neither too near its sun to dry out or too far away which freezes it.
And the discovery could help answer the question of whether we are alone in the universe, which has been plagued astronomers and alien fanatics for years. Scientists found the planet, Gliese 667Cc, orbiting around a red dwarf star, 22 light years away from the earth
Red dwarf stars are the most common stars in the neighbourhood of the sun, usually hosting planets called gas giants, which are not composed of rock matter.
Re-analysing data from the European Southern Observatory, the astronomers found Gliese 667Cc is a solid planet with roughly four and a half times the mass of Earth.
The University Göttingen and University of California scientists have calculated the planet recieves ten per cent less light from its red dwarf star than the Earth gets from the Sun.
As the light is in the infrared area, the planet still receives nearly the same amount of energy as the Earth, meaning water could be liquid and surface temperatures could be similar to ours.
Astronomers are hailing the plant as the 'Holy Grail' of discoveries, as 20 years ago scientists were still arguing about the existence of planets beyond our solar system.
Read the entire article:
http://www.telegraph.co.uk/science/space/9230801/Astronomers-find-new-planet-capable-of-supporting-life.html
|
[Click here to read the rest of this article...]
Online volunteers could be set task of spotting alien technology, evidence of mining and rubbish heaps in moon images. Hundreds of thousands of pictures of the moon will be examined for telltale signs that aliens once visited our cosmic neighbourhood if plans put forward by scientists go ahead.
Passing extraterrestrials might have left messages, scientific instruments, heaps of rubbish or evidence of mining on the dusty lunar surface that could be spotted by human telescopes and orbiting spacecraft.
Though the chances of finding the handiwork of long-gone aliens are exceptionally remote, scientists argue that a computerised search of lunar images, or a crowd-sourced analysis by amateur enthusiasts, would be cheap enough to justify given the importance of a potential discovery.
Prof Paul Davies and Robert Wagner at Arizona State University argue that images of the moon and other information collected by scientists for their research should be scoured for signs of alien intervention. The proposal aims to complement other hunts for alien life, such as the Search for Extraterrestrial Intelligence (Seti), which draws on data from radiotelescopes to scour the heavens for messages beamed into space by alien civilisations.
Read the entire article:
http://www.guardian.co.uk/science/2011/dec/25/scour-moon-ancient-traces-aliens
|
[Click here to read the rest of this article...]
|
