The Search For Second Earth

Related Articles

In the search for planets capable of sustaining life, an international research team with members from ETH has taken a significant step forward.

As the researchers reported recently in the journal Nature Communications, they found signs of a Neptune-sized planet in the Alpha Centauri star system, a mere 4.4 light years away from Earth. This exoplanet is located in a zone that may offer suitable conditions for life. The team was able to collect data with unprecedented sensitivity, thus registering even very weak signals.

Earth is a disruptive factor

 

Thanks to the new process, the researchers have advanced one step closer to a major goal of exoplanet research: the discovery of Earth-like planets capable of supporting life. Direct imaging of planets delivers information about the composition of their atmospheres and possibly even signs of life. To date, however, direct measurements have mostly found exoplanets that are larger than Jupiter and orbit far away from very young host stars. In other words, these planets fall outside the habitable zone where liquid water could form.

One reason that the search for Earth-like planets has so far proved fruitless is that it has been conducted in the near-infrared range, even though Earth-like planets that might have water are brightest in the mid-infrared range. Yet it is precisely in that range that measurements with normal telescopes are difficult, because that is where the Earth and its atmosphere are also at their brightest. This means the faint signals from exoplanets are lost in particularly strong background noise.

100 hours of observations

As reported in their study, the researchers have now been able to overcome this difficulty and take measurements in the mid-infrared range. They used the Very Large Telescope at the European Southern Observatory in Chile to examine Alpha Centauri stars A and B, logging nearly 100 hours over the course of a month. “Keeping the telescope pointed at the same star for such a long time is highly unusual,” explains Anna Boehle, a postdoc in ETH Professor Sascha Quanz’s group. As second author of the study, Boehle was heavily involved in evaluating the data. “We assessed more than five million images,” she says.

To be able to detect the faint signals from potential planets, the researchers not only processed a huge volume of data, they also employed two sophisticated measurement techniques: one was to use a new deformable secondary telescope mirror, which made it possible to correct for distortions in the light coming through the Earth’s atmosphere; and the other was to use a coronagraph to alternately block the light from each of the stars in turn at very short intervals. This let the scientists further reduce signal noise while examining the surroundings of both stars.

Signs of a planet

“Our findings indicate that in principle, this process enables us to discover smaller terrestrial planets capable of hosting life,” Boehle explains, “and it represents a clear improvement over previous observation methods.” Indeed, in their data the researchers found a light signal that may originate from a Neptune-sized planet. Boehle says, “Whether or not this signal is actually from a planet requires further study. To that end, we plan to combine the infrared measurements with other measurement methods.”

ETH ZURICH

Header Image Credit : Public Domain

Download the HeritageDaily mobile application on iOS and Android

More on this topic

LATEST NEWS

The Human Footprints of Ojo Guareña

The CENIEH has participated in the study of the prints of bare feet found at the Sala y Galerías de las Huellas site in the Ojo Guareña Karst Complex (Burgos), which are the marks left in a soft floor sediment of an exploration by a small group of people between 4600 and 4200 years ago.

Roman Villa of Tiberius and the Cave of Imperial Pleasure

The Villa of Tiberius is a ruined Roman villa complex located in the present-day town of Sperlonga, in the province of Latina on the western coast of Italy.

Archaeologists Excavate 1,600-Year-Old Burial Containing Ornate Treasures

Archaeologists excavating a burial ground have discovered a grave containing ornate grave goods from the 5th century AD, a period of instability during the collapse of the Western Roman Empire.

Archaeologists Discover Ancient Settlements Associated With “Polish Pyramids”

Archaeologists conducting a detailed study of the area near the Kujawy megalithic tombs, dubbed the “Polish Pyramids”, have identified the associated settlements of the tomb builders.

Rocky Planet Discovered in Virgo Constellation Could Change Search For Life in Universe

A newly discovered planet could be our best chance yet of studying rocky planet atmospheres outside the solar system, a new international study involving UNSW Sydney shows.

Sungbo’s Eredo – The “Queen of Sheba’s Embankment”

Sungbo’s Eredo is one of the largest man-made monuments in Africa, consisting of a giant system of ditches and embankments that surrounds the entire ljebu Kingdom in the rain forests of south-western Nigeria.

Woolly Mammoths May Have Shared the Landscape With First Humans in New England

Woolly mammoths may have walked the landscape at the same time as the earliest humans in what is now New England, according to a Dartmouth study published in Boreas.

Prehistoric killing machine exposed

Judging by its massive, bone-crushing teeth, gigantic skull and powerful jaw, there is no doubt that the Anteosaurus, a premammalian reptile that roamed the African continent 265 to 260 million years ago - during a period known as the middle Permian - was a ferocious carnivore.

Popular stories

Noushabad – The Hidden Underground City

Noushabed, also called Oeei or Ouyim is an ancient subterranean city, built beneath the small town of Nushabad in present-day Iran.

Ani – The Abandoned Medieval City

Ani is a ruined medieval city, and the former capital of the Bagratid Armenian kingdom, located in the Eastern Anatolia region of the Kars province in present-day Turkey.

Interactive Map of Earth’s Asteroid and Meteor Impact Craters

Across the history of our planet, around 190 terrestrial impact craters have been identified that still survive the Earth’s geological processes, with the most recent event occurring in 1947 at the Sikhote-Alin Mountains of south-eastern Russia.

The Sunken Town of Pavlopetri

Pavlopetri, also called Paulopetri, is a submerged ancient town, located between the islet of Pavlopetri and the Pounta coast of Laconia, on the Peloponnese peninsula in southern Greece.