vendredi 19 novembre 2021

Is there life at Alpha Centauri?

 






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Nov. 19, 2021

Is there life at Alpha Centauri? New space telescope to seek out habitable planets around sun's neighboring star

The new TOLIMAN space telescope could launch in the mid-2020s.

A new space telescope mission unveiled today (Nov. 16) will look for habitable planets in the Alpha Centauri system, our sun's closest stellar neighbors.

The new mission, called TOLIMAN after an ancient Arabic-derived name for Alpha Centauri, will carry a novel telescope fitted with a so-called diffractive pupil lens that spreads starlight into a flowerlike pattern. This unique lens will make it easier for astronomers using the scope to detect tiny irregularities in a stars' movements that are usually caused by the gravitational influence of orbiting planets, according to a statement by Breakthrough Initiatives, which is backing the mission.

"Even for the very nearest bright stars in the night sky, finding planets is a huge technological challenge," Eduardo Bendek, an optical engineer at NASA's Jet Propulsion Laboratory, a collaborator on the mission, said in the statement.

"Our TOLIMAN mission will launch a custom-designed space telescope that makes extremely fine measurements of the position of the star in the sky. If there is a planet orbiting the star, it will tug on the star betraying a tiny, but measurable, wobble," Bendek said.


Image above: This image simulates a view of Alpha Centauri, the nearest star system to the sun, as it could be seen by the new planet-hunting space telescope TOLIMAN. (Image credit: Breakthrough Initiatives).

Alpha Centauri is the closest solar system to Earth and it has three stars, two of which are like our sun. The third star is a red dwarf called Proxima Centauri, a cool but long-lived type of a star that is the most common in the universe.

This red dwarf is known to have at least two exoplanets, one of which appears to be fairly similar to Earth.

But so far, this intriguing star system, just four light-years away from us, has avoided detailed scientific scrutiny, despite the fact that the planets around these stars could present the most convenient destination for humankind outside of our own solar system.

While, for now, a human mission to Alpha Centauri remains in the realm of science fiction, the TOLIMAN telescope will at least attempt to answer some of the most fundamental and pressing questions about its planets. Most importantly, scientists hope to use the new scope to investigate whether these far-off worlds might indeed harbor life, or perhaps provide the right conditions for its survival.

"Our nearest stellar neighbors — the Alpha Centauri and Proxima Centauri systems — are turning out to be extraordinarily interesting," Pete Worden, executive director of the Breakthrough Initiatives, said in the statement. "The TOLIMAN mission will be a huge step toward finding out if planets capable of supporting life exist there."


Image above: The proposed Toliman space telescope to seek out habitable planets around Alpha Centauri. (Image credit: Breakthrough Initiatives).

The mission will focus on the habitable zone around the system's three stars, a region of space in the star's vicinity where liquid water could exist.

"These nearby planets are where humanity will take our first steps into interstellar space using high-speed, futuristic, robotic probes," Pete Klupar, chief engineer of Breakthrough Watch, a branch of Breakthrough Initiatives, said in the statement. "If we consider the nearest few dozen stars, we expect a handful of rocky planets like Earth orbiting at the right distance for liquid surface water to be possible."

Professor Peter Tuthill of the Sydney Institute for Astronomy, who leads the development of the mission, added that TOLIMAN will begin answering the questions about the nature of these intriguing worlds.

"Getting to know our planetary neighbors is hugely important," Professor Tuthill said. "These next-door planets are the ones where we have the best prospects for finding and analyzing atmospheres, surface chemistry and possibly even the fingerprints of a biosphere — the tentative signals of life."


Image above: This wide-field view of the sky Alpha Centauri star system and its surroundings was created from photographic images forming part of the Digitized Sky Survey 2. Image released Oct. 17, 2012. (Image credits: ESO/Digitized Sky Survey 2).

The team, which also includes experts from Australian space-tech firm Saber Astronautics, began working on the mission in April this year, according to the statement.

The mission received $788,000 ($576,000) from the Australian government and is expected to be ready for science in the mid-2020s.

"Our plan is for an agile low-cost mission that delivers results by about the middle of the decade," Tuthill said.

About the Breakthrough Initiatives

The Breakthrough Initiatives are a suite of space science programs – Listen, Starshot and Watch - investigating the fundamental questions of life in the Universe.

In July 2015, together with Stephen Hawking, Yuri Milner announced the launch of the $100 million astronomical program Breakthrough Listen, to reinvigorate the search for extraterrestrial intelligence in the universe. In April 2016, they launched Breakthrough Starshot, a $100 million research and engineering program seeking to develop a new technology for uncrewed interstellar travel. Breakthrough Watch, launched in January 2016, is an astronomical program to develop Earth- and space-based technologies that can find evidence of primitive life on Earth-like planets in our cosmic neighborhood.

Related links:

Breakthrough Initiatives: https://breakthroughinitiatives.org/

Saber Astronautics: https://www.saberastro.com/

NASA’s Jet Propulsion Laboratory (JPL): https://www.jpl.nasa.gov/

Images (mentioned), Text, Credits: Breakthrough Initiatives/Space.com/By Tereza Pultarova.

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