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A new satellite will look for planets around other glasses

NASA is looking for a twin for Earth

At the end of last week, NASA management decided to launch a satellite that will help find planets similar to Earth. FAME (acronym for astrometric mapping of the entire sky), will be launched in 2004 and will analyze the position and intensity of the light of stars, and with it it will be possible to find planets around other suns up to a distance of 1,000 light years.
In recent years, more than 20 planets have been discovered. Around Upsilon Andromeda, for example, three planets were discovered. Recently, a group of astronomers from Tel Aviv and Cambridge universities, led by Prof. Zvi Maza, announced that the third planet farthest from Opsilon Andromeda is ten times heavier than Jupiter. This is the first time
that scientists were able to measure with great precision the size of a planet outside the solar system.

Until now, it was only possible to locate large planets, whose gravitational force affects the orbit of the sun around which they circle. Prof. Akiva Bar-Nun, an expert in planetary sciences at Tel Aviv University and former director of the Israel Space Agency, explains that using the new satellites it will be easier to view space, without the atmospheric disturbances that disrupt viewing with ground telescopes. This way it will be possible to find smaller planets, even ones that are only the size of the Earth.

How do you locate a planet? According to Prof. Bar-Nun, light coming from a star is tested and broken down into its components (its wavelengths or colors). When you notice a change in the wavelength, you conclude according to the Doppler phenomenon, that some body circling the star changes its trajectory - sometimes approaching and sometimes moving away.

However, even when the satellites are placed in space, it will still not be possible to observe small planets directly, because their light is weak. Only the effect of their gravity on their central star (the Sun) can be observed. Therefore, according to Bar-Nun, it seems that it is still too early to detect, for example, the presence of oxygen on these planets.

Prof. Bar-Nun, if there are so many planets, why is life not found?
"If you look at the creation and evolution of life on Earth, it seems that it was created 3.6 million years ago, when only 200 million years ago the Earth was still bombarded with asteroids. During most of the period of life on Earth, they were at the level of micro-organisms - cyanobacteria. Very primitive creatures. Only 700 million years ago, slightly more complicated creatures began to emerge, only in the last 10,000 years can we talk about civilization, and only in the last 100 years has a technological civilization been created. Life is easily created, but life with a technological civilization is a very small fraction of the time that life exists. It is possible that in other places the stars become red giants and swallow the life-bearing planets before they had time to develop."
{Appeared in Haaretz newspaper, 18/10/1999}

The writer worked as a high-tech and science reporter for Haaretz newspaper in 1994-2000

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