17th November 2008 by Giles Smith
From NASA Spitzer Project
NASA scientists have discovered that one of the closest solar systems to ours shows some very striking resemlblances to how are solar system looked when it was a lot younger.
The star at the center of the nearby system, called Epsilon Eridani, is a younger, slightly cooler and fainter version of the sun. Previously, astronomers had uncovered evidence for two possible planets in the system, and for a broad, outer ring of icy comets similar to our own Kuiper Belt.
The outer comet ring around Epsilon Eridani is denser than our comet ring, called the Kuiper belt, because the system is younger.
This new discovery should assist scientists and astronomers to model what our own solar system was like around the time life started taking hold on earth. Astronomers have discovered similar systems before but never one as close, only 10 light years away, to us.
“Because the system is so close to us, Spitzer can really pick out details in the dust, giving us a good look at the system’s architecture,”
said co-author Karl Stapelfeldt of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Asteroid belts are often the left overs from planet formation. The formed planet will then shepherd the nearby belt keeping it in its disk like orbit around its star. An asteroid belt is much easier to detect than an individual planet, but its existence allows astronomers to deduce what the size and composition of nearby planets. Asteroid belts are detected by using infra-red telescopes which can pick out the small releases of heat given off when dust and particles in the belt collides.
Tags: asteroid, asteroid belt, earth, epsilon eridani, history, solar system
Categories: Up in Space •
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29th September 2008 by Giles Smith
Rain on Mars (Credit: NASA
Images of layered sedimentary deposits and deltas on Mars have provided evidence for lakes and flowing rivers that carried eroded material downstream. A team of researchers also believes there is evidence for precipitation in the Red Planet’s past. “For years scientists have been suspecting that the current appearance of the landscape has, in part, been shaped by rivers that cut into the surface,” said Ernst Hauber of the German Aerospace Center. “We can see layered sediments where these valleys open into impact craters. The shape of certain sediments is typical for deltas formed in standing water.” Hauber and his team also believe that surface runoff from rain or snowmelt completes the picture of past water on Mars.
There seems to be more and more evidense coming from NASA’s HiRISE that Mars was once very similar to Earth, in both it’s surface and it’s atmosphere. At some point however Mars has taken a very different tack and ended up as very cold, very dry and very barren. Other recent photographs from Mars show dried up lakes, river valleys, estuarys and other features associated with a once wet planet.
Whatever did happen was very brief in Mar’s overall history and any precipitation that did occur dried up around 3.5 to 3.8 billion years ago.
Read more on Universe Today
Tags: earth, ernst hauber, german aerospace center, hirise, mars, nasa, precipitation, rain, red planet
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7th March 2008 by Giles Smith
Earth & Moon viewed from Mars. Credit: NASA/JPL/University of Arizona
Original Post on Universe Today
This is an absolutely fantastic photo, the earth and moon are being viewed from Mars at an angle 90 degrees to the earth from the Sun. You can quite clearly see the Pacific coast of South America and the bulk of North America above it. The detail in the clouds is pretty good too!
Tags: earth, mars, moon, north america, pacific, south america, sun
Categories: Up in Space •
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18th February 2008 by Giles Smith
Quote
One of the biggest questions in astronomy today is, are there any other Earths out there, and if so, how many?
We know that there are over 100 billion stars in the galaxy, and that a lot of them have planets. But we’re still groping round trying to nail down the frequency of planets, and how many are rocky bodies like Earth (as opposed to gas giants like Saturn and Jupiter).
[..]
A new study using the Spitzer Space Telescope has revealed that planets like Earth may be common! The procedure was actually rather simple. They looked at over 300 sun-like stars, and grouped them by ages (very young, young, middle aged, etc). They then used Spitzer to look for the presence of dust around the stars; dust glows in the infrared when warm, and the temperature (and thus the distance of the dust from the star) can be found.
Given the number of solar systems in our universe the probability of the existence of another earth like planet, has to be nearly 1. However until now this is just theory. This could be quite an exciting step forward to finding other sources of life in our universe.
Tags: earth, space telescope, spitzer, star
Categories: Up in Space •
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14th February 2008 by Giles Smith
Tags: earth, perspective, solar system, star, sun
Categories: Up in Space •
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