[BLANK_AUDIO] We've looked at some of the sorts of
planets that have been Discovered around other stars and the Possibility of searching for earth like
planets. Let's just now review some of the missions
that have been already implemented and are Planned for the future to look for Bio signatures in atmospheres of extra
solar planets. Well, first of all, it's worth noting
again, that the Search for exo-planets is a research field
that is rapidly accelerating. New planets are being discovered all the
time and the various methods that We've looked at for searching for
exo-planets, Are revealing many of these new planets. The first analysis of an extra solar
planetary atmosphere, Was undertaken in 2001 by the Hubble Space
telescope. And it found sodium in the atmosphere of a
hot Jupiter. The first time a definitive element had
been identified in an Extrasolar planetary atmosphere. The Hubble Space Telescope also identified
other gases in 2007. It saw methane and carbon dioxide for the First time in an extra solar planetary
atmosphere, and In 2007 it detected water vapor in the
atmosphere In an extra solar planet assisted Spitzer
Space Telescope. Spitzer Space Telescope is also been a
remarkably Successful mission. It was developed by NASA, European Space
Agency and Caltech. It was launched in 2003 and one of it's Objectives has been to look for Infrared
spectra of exo-planets. It's found water and carbon dioxide in
extrasolar Planetary atmospheres, but it's also made
other discoveries. For example, it's found atmosphere with
dense cloud cover On other planets and it's also found
prebiotic molecules, Potential molecules that could be involved
in early Building blocks of life in young star
systems. Such as a [UNKNOWN], hydrogen and cyanide,
Giving us new insight into the possible
sources Of early molecule, that could be the Building blocks for life in other star
systems. Yet another mission that's being developed
and launched as COROT, this was developed By the French Space Agency in Collaboration with the European Space
Agency and Other organizations.
It was launched in 2006. Now, this mission was not specifically
looking For biosignatures in the atmospheres of
extrasolar Planets, but it has been remarkably
successful In discovering new planets using the
transit method. In fact, it discovered one of the smallest
exoplanets that Was known at the time it was launched,
COROT 7B. Which is about 1.6 times the size of the
Earth. Since that planet was discovered, smaller
earth like planets have been discovered. This has also been a very successful
mission. Perhaps the most remarkably successful
mission in recent years Has been the Kepler space telescope
launched in 2009. And it does have a focus on small
Earth-like planets. It's identified more than 50 planets,
residing near the habitable zone around Other stars. In 2011, it found the first two Earth Sized exo-planets orbiting a star similar
to our own. These planets though, are probably too
close to their sun to have life. They're just too hot, but they did Demonstrate the first detection of rocky
planets of Similar size of the Earth,
terrestrial-type planets, that Were the building blocks of new types of Searches for Earth-like worlds. There are future missions that are
planned. For example, the Gaya Mission, which is
being developed by The European Space Agency, is planned to
be launched in 2013. And it will be capable of detecting Tens of thousands of extra solar planetary
systems.
The James Webb Space Telescope. Developed by NASA, in collaboration with
other space agencies, is also Going to provide a next generation of
infrared analyses, allowing us to Look at the atmospheres of extra solar
planets. And EChO is a European Space Agency Mission, planned for somewhere around
2020, that is Specifically focused on the
characterization of atmospheres on Planets, within the habitable zones of
their stars. There are also plans to develop
sophisticated methods, based on the Surface of the Earth, that would look for
extra solar planets, Extremely large telescopes that would have
the capacity to look at Extra solar planets, and possibly to try
and image them directly. There are three projects funded today and
they may enable us to look for earth like Planets, looking directly at the light
given off By those planets and so directly image
them. So what have we learned? We've learned that the first analysis of
an exoplanetary atmosphere Was performed by the Hubble Space
Telescope. We've learned that since then several
exo-planet missions have been launched. The Spitzer space telescope, COROT and
KEPLER as examples. And we've already found prebiotic
molecules in early star Systems, and begun to characterize the
atmospheres of extra-solar planets. We're not yet at the position of being
able to look for biosignatures. But we now know How to look for spectra of exo-planets. And since the launch of KEPLER in 2009,
the known number of planets in Habitable zone or near the habitable zone
of distant stars is greater than 50. And several new initiatives for exo-planet
research is scheduled in the next decade. With an increasing focus on life detection
missions, eventually leading To telescopes that will allow us to search
for the Bio signatures of life in the atmospheres
of extrasolar planets.
