When it comes to finding an Earth-like planet, we may have just made the closest discovery yet – this world lies less than 16 light-years away and is within its star’s habitable zone.
Wolf 1069 b is likely tidally locked to its host star, meaning the same side always faces toward it. Yet its closeness suggests it could retain an atmosphere.
Proxima Centauri b
Proxima Centauri b is the closest exoplanet to Earth, at only 4.2 light years away. It boasts many intriguing qualities that set it apart, including being approximately 1.3 times the size of Earth and orbiting an extremely common type of star called a red dwarf star – giving it similar amounts of energy as Earth and meaning liquid water could exist on its surface; however it would need to contend with radiation, flares from its host star as well as possible tidal locking (when one side always faces away from its host star at all times).
At present, our understanding of Proxima Centauri b is limited to analysing its atmosphere during transit – when it passes in front of its star – which requires precise timing in terms of stars being in alignment. Soon though, instruments like Chile’s 39-meter E-ELT telescope will give us direct image access of any planet circling red dwarf stars that may or may not possess atmospheres and liquid water reservoirs.
Researchers are currently employing computer simulations to investigate the possibility of life on Proxima Centauri b, using different climate scenarios as they run them and discovering that nearly all end with at least some open oceans on at least some parts of its surface. Parameters used include giant continents, thin atmospheres, changes in salt content in ocean waters as well as rotating planets with changing environments simulated within.
Scientists who authored the paper express optimism that Proxima Centauri b will be an exciting target for future research. They have already begun planning experiments that will utilize E-ELT when completed and are eager to discover its atmosphere – even suggesting they might detect carbon dioxide there!
However, the authors caution against expecting to find water or signs of life on Proxima Centauri anytime soon. They note the chances are still fairly remote because much of its original water may have been lost through early irradiation or its planet being locked into an orbit with only half its surface exposed daily to sunlight.
TRAPPIST-1
Last year, astronomers discovered seven Earth-sized planets orbiting a red dwarf star within 40 light-years – each having temperatures ideal for liquid water to exist – making them prime candidates in the search for extraterrestrial life. Now, a new study provides details about these worlds and their environments.
Scientists now possess a much deeper understanding of these seven planets than ever before, including their densities and compositions. With more precise information, scientists are better equipped to predict about their interiors; preliminary findings indicate that most are probably composed of rocks while two could possibly have atmosphere or an ice layer on top.
TRAPPIST-1b is likely a barren rock with a surface temperature of approximately 232 degrees Celsius and an iron core that could produce powerful magnetic storms; its surface lacks sufficient depth to host thick atmosphere or oceans, and likely does not support an ecosystem similar to our own Earth’s. TRAPPIST-1d, 1e and f are less dense but more likely to host an atmosphere or ice layer than TRAPPIST-1b.
They also orbit closer to their host stars than our solar system planets, increasing the likelihood of volcanic eruptions which cause dangerous radiation storms ten to a thousand times more powerful than Earth-based geomagnetic storms and alter the chemical makeup of atmospheres while gradually eroding them over time.
Astronomers were thrilled to find these Earth-sized worlds, yet it’s unlikely any have life. Being so close to their respective stars means these planets are tidally locked – meaning one side always faces away from them and the resultant gravitational tidal heating can destroy any atmospheres the planet might possess or even boil away any existing water resources.
The James Webb Space Telescope, set for launch this October, can delve deeper into these planets’ exploration. It can detect gases within their atmospheres and possibly detect signs of life on these worlds.
Kepler-452b
Kepler-452b lies approximately 1,400 light-years away from Earth. But this distant relative stands out as being unique; it is the first near-Earth size planet ever discovered within the habitable zone of a star like our sun and it may support life; scientists have yet to ascertain this fact, though similarities between Kepler-452b and Earth do exist such as water availability and other essential necessities for survival.
Kepler-452b has similar dimensions to Earth and orbits a star that is roughly 10 percent larger than our Sun. Each year on this planet lasts 385 days, making it an attractive option for future human explorers as its orbit makes it relatively close to its parent star and easier for spacecraft to reach. According to Ryan Weed from Positron Dynamics, traveling at 1g acceleration would allow one spacecraft traveling to Kepler-452b within 12 years using time dilation effects which allow faster-than-light travel and cover more distance in less time.
Though we may never actually set foot on Mars, it remains fascinating to consider its possibilities – particularly after discovering water there recently – suggesting it once supported life on its surface.
Astronomers used the Kepler telescope and ground observatories such as McDonald Observatory in Texas, Whipple Observatory in Arizona and Keck Observatory in Hawaii to discover a new planet. They published their results in The Astronomical Journal using transit timing variations (TTV) techniques to estimate mass and size of exoplanets.
Researchers estimated that this planet was approximately 4.8 times the size of Earth and had between three and seven Earth masses, per the estimates from their models of stellar evolution. They believe it orbited a Sun-like star that is about 1.5 billion years older than our Sun, with temperatures that approximate ours; they speculate that its older age has allowed liquid water to remain on its surface.
OGLE-2005-BLG-390Lb
OGLE-2005-BLG-390Lb is an Earth-sized planet discovered using gravitational microlensing technology. This technique detects low-mass planets orbiting distant stars by observing starlight through an intervening lens; light from the background star passes through this lens and becomes magnified and distorted due to gravity effects on this lens star; when coupled with a planet accompanying said foreground star, its light may bend differently resulting in brightening signals lasting anywhere from days in the case of giant planets up to hours for Earth-sized planets!
Astronomers using the Optical Gravitational Lensing Experiment (OGLE), a survey which regularly scans most of the central region of our Milky Way each night, noticed an promising microlensing event on July 11, 2005 and immediately informed PLANET and MOA telescope networks. Both networks began closely monitoring this lensing star with their telescopes until July 31st when brightening reached its maximum brightness level before gradually diminishing thereafter; on August 9th however a slight planetary deviation was discovered at ESO La Silla while Perth 0.6m also confirmed this event on that same day via its OGLE points collected through both networks.
Observations of the lensing star’s light suggest that this planet has five times Earth’s mass and an approximate temperature near 50 Kelvin below absolute zero (220 degC). Due to this extremely cold temperature, any gases present are likely frozen; thus implying it may more resemble Pluto or cores of ice giants such as Uranus and Neptune rather than our Solar System’s inner planets.
Microlensing surveys have for the first time detected low-mass planet signals; previously discovered extrasolar planets had only been gas giants. Furthermore, this discovery marks one of the farthest and coldest ever made; situated 21,500 light-years from Earth near its centre – it lies near Scorpius constellation in our Galaxy.