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Newly discovered nearby planet could support life
Newly discovered nearby planet could support life
Story highlights
- Newly found exoplanet is the second-closest to our solar system and could support life
- Ross 128 b orbits a "quiet" star that isn't lashed with radiation
(CNN)You
may want to get used to the name Ross 128 b. The newly discovered
exoplanet is the second-closest found to our solar system, only 11
light-years away. And it could support life.
Announcements
about exoplanets, those found outside our solar system, seem almost
commonplace in this golden age of discovery for astronomers. So why is
Ross 128 b unique -- apart from its rather human-sounding name?
The
planet is about the same size as Earth, and it may have a similar
surface temperature, making it a temperate world that could support
life.
Every
9.9 days, it completes an orbit around its host star, Ross 128, which
is what's known as a red dwarf star: They're the coolest, faintest and
most common stars found in the universe.
Because
of their plentiful nature and the fact that other exoplanets have been
found around these types of stars, red dwarfs are being studied and
observed with increasing frequency in the hopes of finding more
exoplanets.
Astronomers
found Ross 128 and its planet using the European Southern Observatory's
planet-hunting instrument, called HARPS. The High Accuracy Radial
velocity Planet Searcher is based at La Silla Observatory in Chile. The
astronomers detail their discovery in a new study, published Wednesday
in the journal Astronomy and Astrophysics.
"To
be involved in such a discovery is very rewarding, and it helps to
realize that so much effort is worth it," Nicola Astudillo-Defru, one of
the study's co-authors at the University of Geneva's observatory, wrote
in an email. "The special properties of this system means that we are
contributing our bit on the search of an Earth 2.0."
Other notable discoveries of Earth-size exoplanets in recent years, like the TRAPPIST planets and Proxima b,
were also found around these types of stars. They are also considered
to be among the best hopes for supporting life on planets outside our
solar system because they exist within the "habitable zones" of their
stars, where liquid water could pool on the surface of the planet and
potentially support life as we know it.
The
astronomers don't yet know whether Ross 128 b is in the habitable zone
of its star, but it's likely, given what they understand about red
dwarfs and the planets that orbit them.
Ross
128 b is 20 times closer to its star than Earth is to the sun, but
because the star is small, dim and cool, the planet would still be at a
potentially comfortable temperature. The nature of the star is also why
the planet is subjected to only 1.38 times the radiation that Earth
receives from the sun, even though the planet and star are close
together.
But the reason
astronomers are excited about Ross 128 b is because the star is "quiet."
Other red dwarfs, like Proxima Centauri -- the star that Proxima b
orbits -- have a tendency to lash out at their planets with deadly
flares of ultraviolet and X-ray radiation.
But
Ross 128 doesn't seem to be doing this, so it's considered "quieter,"
which means the planet is a more comfortable place for life to form
without being subjected to such violent episodes from time to time.
Proxima
b is currently the closest exoplanet to our solar system ever
discovered, at a distance of 4.2 light-years. Ross 128 b could change
this, because the planet and its star are moving toward us.
"A detailed study investigated
the movement of our stellar neighbor by combining data from the
Hipparcos satellite and ground-bases velocimeters," Astudillo-Defru
said. "They list all the close encounters with other stars, and because
of the relative movements of stars and the Sun, it results that Ross 128
will be our closest star."
Astronomers
estimate that in 79,000 years, Ross 128 b will be our exoplanet
neighbor, even closer than Proxima b. That may sound like a long time,
but in a universe that is billions of years old, it's merely a cosmic
moment.
The astronomers believe
that Ross 128 b is a good candidate for further study when the European
Southern Observatory's Extremely Large Telescope can begin searching the
atmospheres of exoplanets for biomarkers in 2025.
"I
plan to continue searching for new worlds, specially around Ross 128
because it is likely that there are more planets," Astudillo-Defru said.
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