Kepler telescope spies 'most
Earth-like' worlds to date

The search for a far-off twin of Earth has turned up two of the most
intriguing candidates yet. Scientists say these new worlds are
the right size and distance from their
parent star, so that you might expect
to find liquid water on their surface. It is impossible to know for sure.
Being 1,200 light-years away, they
are beyond detailed inspection by
current telescope technology. But researchers tell Science magazine, they are an exciting discovery. "They are the best candidates found
to date for habitable planets," stated Bill Borucki, who leads the team working on the US space agency
Nasa's orbiting Kepler telescope. The prolific observatory has so far
confirmed the existence of more than
100 new worlds beyond our Solar
System since its launch in 2009. The two now being highlighted were
actually found in a group of five
planets circling a star that is slightly
smaller, cooler and older than our
own Sun. Called Kepler-62, this star is
located in the Constellation Lyra. Its two outermost worlds go by the
names Kepler-62e and Kepler-62f. They are what one might term
"super-Earths" because their
dimensions are somewhat larger than
our home planet - about one-and-a-
half-times the Earth's diameter. Nonetheless, their size, the
researchers say, still suggests that
they are either rocky, like Earth, or
composed mostly of ice. Certainly,
they would appear to be too small to
be gaseous worlds, like a Neptune or a Jupiter. Many assumptions Planets 62e and 62f also happen to sit
a sufficient distance from their host
star that they receive a very tolerable
amount of energy. They are neither
too hot, nor too cold; a region of
space around a star sometimes referred to as the "Goldilocks Zone". Given the right kind of atmosphere, it
is therefore reasonable to speculate,
says the team, that they might be able
to sustain water in a liquid state - a
generally accepted precondition for
life. "Statements about a planet's
habitability always depend on
assumptions," said Lisa Kaltenegger, an expert on the likely atmospheres
of "exoplanets" and a member of the
discovery group. "Let us assume that the planets
Kepler-62e and -62f are indeed
rocky, as their radius would indicate.
Let us further assume that they have
water and their atmospheric
composition is similar to that of Earth, dominated by nitrogen, and
containing water and carbon
dioxide," the Max Planck Institute for
Astronomy in Heidelberg researcher
went on. "In that case, both planets could have
liquid water on their surface:
Kepler-62f gets less radiation energy
from its host star than the Earth from
the Sun and therefore needs more
greenhouse gases, for Instance more carbon dioxide, than Earth to remain
unfrozen. "Kepler-62e is closer to its star, and
needs an increased cloud cover -
sufficient to reflect some of the star's
radiation - to allow for liquid water on
its surface." Key signatures None of this can be confirmed - not
with today's technology. But with
future telescopes, scientists say it may
be possible to see past the blinding
glare of the parent star to pick out just
the faint light passing through a small world's atmosphere or even reflected
off its surface. This would permit the detection of
chemical signatures associated with
specific atmospheric gases and
perhaps even some surface
processes. Researchers have spoken
in the past of trying to detect a marker for chlorophyll, the pigment in plants
that plays a critical role in
photosynthesis. Dr Suzanne Aigrain is a lecturer in astrophysics at the University of
Oxford. She said ground-based experiments
and space missions planned in the
next few years would give more
detailed information on distant
planets like those announced by the
Kepler team. Astronomers would like to pin down
the masses of the planets
(information difficult to acquire with
Kepler), as well as getting that data on
atmospheric composition. Dr Aigrain told BBC News: "What we
do next is we try to find more systems
like these; we try to measure the
frequency of these systems; and we
try to characterise individual systems
and individual planets in more detail. "That involves measuring their
masses and their radii, and if possible
getting an idea of what's in their
atmospheres. But this is a very
challenging task." Kepler meanwhile will just keep
counting planets beyond our Solar
System. It is equipped with the largest camera
ever launched into space. It senses
the presence of planets by looking for
a tiny "shadowing" effect when one
of them passes in front of its parent
star.

1,200 light years and we have not invented machine to even take us to Mars in 24hrs.

lol..... they're definitely working on it