It's an exciting find given the planet is only six light-years away from Earth, making it one of closest worlds outside of our solar system.


Credit: Getty Images: Ron Miller/Stocktrek Images

Primitive life might exist on a large, rocky planet that is
relatively nearby Earth, according to a team of scientists who
presented their work at an astronomy conference last
week.

The team says that the planet – known as Barnard b or GJ 699 b
– might have microbes or other simple life in its environment as
long as there is a lot of thermal activity within the planet
itself. This would theoretically provide enough energy for life to
survive.

It’s an exciting find given that the planet is only six light-years
away from Earth, making it one of closest worlds outside of our
solar system. There is another potentially habitable planet at
Proxima Centauri roughly four light-years away from us, which is
also coming under scrutiny. (A light-year is the distance light
travels in year, or 5.88 trillion miles (9.5 trillion km).

The planet orbits Barnard’s star, a red dwarf star that is slightly
smaller and cooler than our sun. Like many stars of its type,
Barnard’s star puts out a lot of X-ray and ultraviolet radiation
that could hurt any nascent life on the planet. However, the planet
lies a little outside of the worst of the radiation, providing hope
that life could indeed survive as long as it is hardy.

The planet is probably a super-Earth, roughly three times the mass
of our own planet. Scientists suspect super-Earths like this one
have a large, hot iron core with higher geothermal energy compared
with Earth. This geothermal energy could heat the planet’s
environment using vents or plumes, similar to what happens in ocean
environments on Earth – even in cold areas like
Antarctica.

In their presentation, the researchers jokingly compared the planet
to Hoth – the icy planet made famous in one of the “Star Wars”
movies, when Luke Skywalker’s steed (a fictional lizard species
called a Tauntaun) dies and he must stay warm by burrowing into its
intestines.

But the challenge for the team is proving life may exist on the
newly discovered planet, which was first announced
in November in a Nature publication
. There’s no telescope
powerful enough yet to look at the planet’s atmosphere for
biologically friendly molecules, such as oxygen or methane. That
would require – at the least – the launch of NASA’s James Webb
Space Telescope, which is set to go to space no earlier than 2021.
Or it may require an even more powerful telescope in the
future.

“Directly imaging the planet would be able to tell us its precise
brightness, and we could gather more information about temperature
and properties such as albedo [reflectivity],” said Villanova
Unviersity astrophysicist Scott Engle to Seeker; he participated in
the research along with fellow Villanova astrophysicist Edward
Guinan. Guinan provided a copy of their presentation to Seeker.

Albedo is helpful in part because it can tell astronomers if the
surface is made of highly reflective materials, such as ice, or
less reflective materials, such as rock. Since life as we know it
prefers water, a planet with water or water ice on its surface
would have a stronger argument for habitability.

The study of life on other worlds is still in its infancy and few
spacecraft have looked for life directly. NASA is working on a
mission called Europa Clipper that could look for habitable
conditions at Jupiter’s icy moon, Europa. Europa has a liquid ocean
under its ice because the tidal energy from strong Jupiter keeps
the ocean from freezing over. 

“Getting more data on Europa would be very impactful,” Engle said.
“Currently we are left with theories and a few Earth-based examples
of subsurface oceans such as Lake Vostok in Antarctica. Studies at
icy moons, the Holy Grail of which would be something like the
Europa Clipper, would finally advance us beyond the boundaries of
terrestrial examples like Lake Vostok … which would be huge.”

While the astronomers wait for these datasets to become available,
they still have other ways of gathering information; they will
examine the star’s wobble to see if they can learn any more
properties about the planet, and to search for any planetary
companions. The team will monitor the variations in the star’s
light to pin down the star’s rotation, and also to look for
sunspots – just like on the sun.

They also are looking at alternative techniques to take images of
the planet. They have a couple of early ideas already. Perhaps they
will use a set of telescopes on the Earth working together as an
interferometer, or use extremely sensitive adaptive optics that
could help the telescope deform its mirror to counteract
atmospheric turbulence that blurs out the sky.

The researchers presented their work at a Jan. 10 press conference
held at the 233rd meeting of the American Astronomical Society in
Seattle.

Source: FS – All – Science – News 2
It's an exciting find given the planet is only six light-years away from Earth, making it one of closest worlds outside of our solar system.