* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Questions to answer - high school teachers at CERN
Perseus (constellation) wikipedia , lookup
Star of Bethlehem wikipedia , lookup
Geocentric model wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Cygnus (constellation) wikipedia , lookup
Circumstellar habitable zone wikipedia , lookup
Space Interferometry Mission wikipedia , lookup
Fermi paradox wikipedia , lookup
Kepler (spacecraft) wikipedia , lookup
Nebular hypothesis wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
History of astronomy wikipedia , lookup
Astronomical unit wikipedia , lookup
Cosmic distance ladder wikipedia , lookup
Star formation wikipedia , lookup
Drake equation wikipedia , lookup
Corvus (constellation) wikipedia , lookup
Astrobiology wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Dwarf planet wikipedia , lookup
Astronomical naming conventions wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Directed panspermia wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Observational astronomy wikipedia , lookup
Planets in astrology wikipedia , lookup
IAU definition of planet wikipedia , lookup
Exoplanetology wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Definition of planet wikipedia , lookup
Ancient Greek astronomy wikipedia , lookup
Extraterrestrial life wikipedia , lookup
High School Teachers 2006 Questions to answer 1.How can we understand if what we see is a star or a planet?(or something else…..) 2.Can you imagine an easy way to find how far a star is from the earth? 3.Can you understand what the materials are in the star from that distance? 4.If there are stars like our sun is it possible to have planets like our planet? Are We Alone? 1.How can we understand if what we see is a star or a planet?(or something else…..) Planets If we consider the Earth as the centre of the solar system then the sun and the planets are in the same plane. So the planets during the night must be in the same trajectory as the sun in the day. But….. How can we distinguish the planets from the stars even in this narrow plane? Stars In the case of a planet the cone of light in the surface of the upper atmosphere is about a few hundred meters but in the case of a star is only a few cm. So the atmospheric turbulence may affect the image of the stars but not those of the planets. That is why the stars twinkle at night but the planets do not. 2.Can you imagine an easy way to find how far a star is from the earth? practically For the Sun Intensity of light Distance I 0 1000W / m2 8 min 108 Km 105 yl For a star (like our sun) We can imagine that a star looks like a light of 100W at a distance of 10Km Intensity of light I P 7 2 10 W / m r2 Io Io r 2 P P 2 / 2 2 r yl Distance I ro r I ro Exact methods of finding distances Exact but only for near objects Parallax sin 1AU r 1AU / sin r Only for distances up to 200 light years Star distance Astronomical unit =1AU r Other methods…….. As far as we can see •Standard Candles Novae 6 million light years Supernovae 30 million light years Cepheid 60 million light years M m 5(log 10 D 1) •Hubble's Law v =H D 1billion light years Example For this type of stars we can evaluate with great accuracy the absolute magnitude by change of the period of luminosity 3.Can you understand what the materials are in the star from that distance? The analysis of light is a common phenomenon Spectroscopy Continuous spectrum Hot gas Emission spectrum Cold gas Absorption spectrum Each element is responsible for a different set of absorption lines in the spectrum so the spectrum indentifies the element like the fingerprint indentifies the human. Spectroscopy mechanism Cold gas The absorption spectrum of the sun 4.If there are stars like our sun is it possible to have planets like our planet? Are We Alone? What is this; UFO Sightings Map: Western Hemisphere If you don’t believe…. THEORIES panspermia Exogenesis MATHEMATIC CALCULATION DRAKE EQUATION N is the number of civilizations in our galaxy with which we might expect to be able to communicate at any given time and R* is the rate of star formation in our galaxy fp is the fraction of those stars that have planets ne is average number of planets that can potentially support life per star fl is the fraction of the above that actually go on to develop life fi is the fraction of the above that actually go on to develop intelligent life fc is the fraction of the above that are willing and able to communicate L is the expected lifetime of such a civilization Current estimates of the Drake equation parameters N=0,000008 Direct search Arecibo message SETI (Search for ExtraTerrestrial Intelligence) OBSERVATIONS OF EXTRASOLAR PLANETS Multiple planet systems There are currently 45 known planets in 19 multiple planet systems Single planet systems There are currently 144 known planets in single-planet systems GQ Lupi on 25 June 2004 with the adaptive optics instrument MISSIONS FOR EXTRASOLAR PLANETS SEARCHING NASA Kepler Mission (2008) Kepler spacecraft ESA Darwin (2015) Darwin