Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Are We Alone in the Universe?
Document related concepts
Astrophotography wikipedia , lookup
Copernican heliocentrism wikipedia , lookup
Fermi paradox wikipedia , lookup
Corvus (constellation) wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Cygnus (constellation) wikipedia , lookup
Geocentric model wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Nebular hypothesis wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Spitzer Space Telescope wikipedia , lookup
History of astronomy wikipedia , lookup
Satellite system (astronomy) wikipedia , lookup
Observational astronomy wikipedia , lookup
Planets in astrology wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Astronomical spectroscopy wikipedia , lookup
Space Interferometry Mission wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Dwarf planet wikipedia , lookup
Circumstellar habitable zone wikipedia , lookup
Astronomical naming conventions wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
IAU definition of planet wikipedia , lookup
Definition of planet wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Astrobiology wikipedia , lookup
Exoplanetology wikipedia , lookup
Directed panspermia wikipedia , lookup
Kepler (spacecraft) wikipedia , lookup
Ancient Greek astronomy wikipedia , lookup
Planetary habitability wikipedia , lookup
Transcript
Are We Alone in the Universe? Dr. Mike MacCallum! Long Beach City College! [email protected] First, a word from our sponsors ✤ ✤ Astronomy at LBCC! http://www.lbcc.edu/astronomy How many planets have we found around other stars? How many planets have we found around other stars? ✤ ✤ ✤ ✤ 1) None! 2) 123! 3) 781! 4) 1,791 How many planets have we found around other stars? ✤ ✤ ✤ ✤ 1) None - don’t raise your arms! 2) 123 - raise your right arm! 3) 781 - raise your left arm! 4) 1,791 - raise both arms How many planets have we found around other stars? ✤ 1,791 - raise both arms How many planets have we found around other stars? ✤ 1,791 + 3,845 more unconfirmed planet candidates from Kepler data Discovery Methods ✤ ✤ ✤ ✤ ✤ ✤ Method! Pulse measurements of pulsars! Gravitational microlensing! Direct imaging! Spectroscopic radial velocity! Transits! Planets! 14! 29! 48! 565! 1,133! Systems! 11! 27! 44! 424! 615 Pulse Measurements of Pulsars ✤ Neutron stars - spinning a very high rates! ✤ A supernova remnant!! ✤ The presence of planets alter the timing of the pulses! ✤ 14 planets discovered in 11 planetary systems Gravitational Microlensing ✤ Change in the appearance of a background star due to the microlensing caused by the gravity of a planet! ✤ Confirmation of Albert Einstein’s general theory of relativity! ✤ 29 planets discovered in 27 planetary systems Direct Imaging ✤ Very difficult because stars are so much brighter than planets! ✤ Infrared imaging is better than imaging in visible light! ✤ 48 planets discovered in 44 planetary systems Radial Velocity or Astrometry ✤ The slight wobble in a star’s orbit due to the tug on it by its planet(s)! ✤ Biased to detecting large planets, close to stars! ✤ Very difficult method to find Earth-like planets! ✤ 565 planets discovered in 424 planetary systems Transit ✤ The Kepler spacecraft! ✤ Launched on March 7, 2009! ✤ May 11, 2013, a second reaction wheel failed, ending the mission! ✤ Continuously monitored 170,000 stars in Cygnus! ✤ http://kepler.nasa.gov/! ✤ https://www.zooniverse.org/project/planethunters! ✤ 1,133 planets discovered in 615 planetary systems The First Discovery ✤ Gamma Cephei! ✤ 1988! ✤ Bruce Campbell, G. A. H. Walker, and Stephenson Yang of University of Victoria and University of British Columbia! ✤ Confirmed in 2003! ✤ Method used: radial velocity The First Confirmed Discovery ✤ Pulsar PSR 1257+12! ✤ January 9, 1992! ✤ Radio astronomers Aleksander Wolszczan and Dale Frail! ✤ Method used: timing of pulses The First Confirmed Planet ✤ ✤ 51 Pegasi - a sun-like star! ✤ October 6, 1995! ✤ Michel Mayor and Didier Queloz of the University of Geneva! ✤ Method used: radial velocity! 51 Pegasi b! ✤ About half the mass of Jupiter! ✤ Orbiting around its star in 4.23 days Extrasolar Planets ✤ Extrasolar planets encyclopedia! ✤ http://exoplanet.eu/ Our Solar System ✤ If the Solar System were a fairy tale, which would it be?! ✤ 1) Sleeping Beauty! ✤ 2) Little Red Riding Hood! ✤ 3) Goldilocks and the Three Bears! ✤ 4) The Three Little Pigs Our Solar System ✤ If the Solar System were a fairy tale, which would it be?! ✤ 1) Sleeping Beauty - don’t raise your arms! ✤ 2) Little Red Riding Hood - raise your right arm! ✤ 3) Goldilocks and the Three Bears - raise your left arm! ✤ 4) The Three Little Pigs - raise both your arms The Habitable (Goldilocks) Zone ✤ The sweet spot! ✤ Where liquid water can exist Potentially Habitable Exoplanets ✤ Habitable exoplanets catalog! ✤ http://phl.upr.edu/projects/habitable-exoplanets-catalog Kepler 186f ✤ The first Earth-like planet in its star’s habitable zone! ✤ Announced April 17, 2014! ✤ 500 light years away! ✤ http://www.nasa.gov/ames/kepler/nasas-kepler-discovers-first-earth-size-planet-in-the-habitable-zone-of-another-star/#.U3ZUCl6gKWU Is There Life on Kepler 186f? ✤ ✤ ✤ If water is present, liquid water should exist on Kepler 186f! It is close to its star! ✤ The star must be stable—not too many flares! ✤ Kepler 186f may be tidally locked, like the Moon is to Earth! When Kepler 186f transits it sun! ✤ We can look for the change in the light of the star! ✤ How that light changes may give information about its atmosphere! ✤ NASA is studying how Earth would look from a distant star Kepler 186f ✤ ✤ ✤ You have been appointed by the UN to compose a digital message to send to Kepler 186f. You can include anything (text, video, audio) in your message. There is no message limit.! The Kepler 186f is 500 light years away! What message will you send? Are We Alone in the Universe? ✤ ✤ ✤ Until about 20 years ago, we only knew about 8 (9 then) planets! ✤ Now we know of nearly 2,000! Some estimates put the number of Earth-like planets in habitable zones at 20% of all stars! ✤ 400 billion stars in the Milky Way x 20% = 80 billion potentially habitable planets! Statistically, the answer is: There have to be other life forms out there But, Where are They? ✤ ✤ ✤ Speed limit on the universe! ✤ The speed of light = 186,000 miles per second! The distance between the stars! ✤ The closest star is Proxima Centuri! ✤ 4.2 light years away = 25 trillion miles! Aiming a message! ✤ Kepler 186f is a tiny, moving target! ✤ Radio signals spread out and become fainter New Missions ✤ GAIA - European Space Agency (ESA)! ✤ Launched December 19, 2013 - currently making observations! ✤ Will survey more than a billion stars in the Milky Way! ✤ Provide a 3D map! ✤ Will detect 10,000 to 50,000 extrasolar planets! ✤ http://sci.esa.int/gaia/ New Missions ✤ Transiting Exoplanet Survey Satellite (TESS) - NASA! ✤ Scheduled for launch in 2017! ✤ Will look for transiting exoplanets among the brightest stars near the Earth! ✤ http://space.mit.edu/TESS/TESS/TESS_Overview.html New Missions ✤ James Webb Space Telescope (NASA)! ✤ An infrared space telescope! ✤ Should be sensitive enough to directly image extrasolar planets! ✤ Launch date: 2018! ✤ http://www.jwst.nasa.gov New Missions ✤ PLATO - European Space Agency (ESA)! ✤ Launch date: 2024! ✤ Will study rocky, Earth-like planets around nearby stars! ✤ http://sci.esa.int/plato/ Thank you for your attendance
