Scientists are developing a laser-powered SAIL that they claim could enable us to detect Alpha Centauri. reach
It’s our closest galaxy and may have the best chance of finding extraterrestrial life, but it would take thousands of years to reach Alpha Centauri with current technology.
The good news is that scientists may have found a way to get there in the space of a lifetime.
It involves a laser-powered sail that they claim could one day allow us to travel 24 trillion miles and reach our nearest star neighbor within 20 years.
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Concept: Scientists develop a laser-powered sail (pictured in an artist’s impression) that they claim could travel 24 trillion miles to Alpha Centauri within 20 years
WHAT IS ALPHA CENTAURI AND HOW CAN WE GET THERE?
The Alpha Centauri galaxy is 24 trillion miles (4.37 light-years) away.
With the fastest spacecraft today, it would take thousands of years to get there.
Breakthrough Starshot aims to find out whether a gram-scale nanocraft propelled on a sail by a beam of light can fly more than a thousand times faster.
Astronomers estimate that there is a reasonable chance that an Earth-like planet exists in the ‘habitable zones’ of Alpha Centauri’s three star system.
The new type of spacecraft propulsion system was designed by scientists at the Australian National University (ANU) as part of an international initiative to explore the worlds around Alpha Centauri.
The Breakthrough Starshot project requires the design of an ultra-lightweight spacecraft, acting as a light sail, to travel at unprecedented speed to the triple star system 4.37 light-years away.
While that’s a great distance in terrestrial terms, it’s three times closer than the next closest Sun-like star.
The concept would have probes launched into space by the laser propulsion system.
Light to power the sail would come from Earth’s surface — with millions of lasers joining forces to illuminate the sail and propel it on its interstellar journey.
“To bridge the vast distances between Alpha Centauri and our own solar system, we need to think outside the box and invent a new way of interstellar space travel,” said Dr Chathura Bandutunga, lead author of the study.
Once underway, the sail will fly through the vacuum of space for twenty years before reaching its destination. During its flyby of Alpha Centauri, it will record images and scientific measurements that it sends back to Earth.”
Located at a distance of 4.37 light-years, Alpha Centauri is home to three stars: Centauri A, Centauri B, and Proxima Centauri. An artist’s impression of the nearest galaxy is depicted
Pictured, a non-to-scale representation of how far Proxima B is from Earth compared to Voyager 1, the farthest man-made object launched in 1977
One potential stumbling block, however, is the sheer amount of lasers needed to steer the probes and make them work as one.
“The Breakthrough Starshot program estimates the total optical power needed to be about 100 GW — about 100 times the capacity of the world’s largest battery today,” said Dr. Robert Ward of the ANU Research School of Physics.
“To achieve this, we estimate the number of lasers needed at about 100 million.”
Proxima b: The closest exoplanet to Earth
Proxima b is the closest exoplanet to Earth and the closest planet to the star Proxima Centauri.
It orbits within the star’s habitable zone – but since Proxima Centauri is a red dwarf and much smaller than the Sun, this zone is very close to the star.
Proxima b orbits its star every 11.2 Earth days and has a mass about 1.2 times that of Earth.
The rocky world is subject to solar winds 2,000 times greater than those on Earth from the sun.
Although it is in a zone where liquid water can form, these stellar winds make it unlikely that life could form.
The planet was discovered in August 2016 and is likely tidally locked.
For these reasons, despite being in the habitable zone, its actual habitability has not been established.
Studies have suggested that the planet could have surface oceans and a thin atmosphere, but that has not been confirmed.
Astronomers won’t know if it has water or an atmosphere until it can be seen in front of its star — which has yet to happen.
If water and an atmosphere are present, even with the extensive radiation, it is possible that life originated on the planet.
Scientists hope the James Webb Space Telescope – which should come online in November this year – can detect the atmosphere of Proxima Centauri b.
There is also a theoretical mission to send a probe to the planet in 2069 to look for biosignatures.
To orchestrate the show, the ANU design calls for a Beacon satellite – a guide laser that will be placed in orbit and act as the guide to bring all the lasers together.
dr. Bandutunga said the study, like the final light sail, is at the beginning of a long journey.
“While we’re confident in our design, the proof is in the pudding,” he said.
‘The next step is to test some basic building blocks in a controlled laboratory setting. This includes the concepts of combining small arrays to create larger arrays and the atmospheric correction algorithms.
‘The job of the ANU was to see if this idea might work. The aim was to find out-of-the-box solutions, to simulate them and to determine whether they are physically possible.’
In 2017, NASA revealed that it had begun planning a mission to Alpha Centauri, hoping to depart on the 100th anniversary of the Apollo 11 mission, in 2069.
Currently, only two man-made spacecraft have left our solar system – Voyager 1, which launched 40 years ago and is currently traveling at about 38,000 miles per hour, and its twin craft Voyager 2.
Voyager 2 was launched 16 days before Voyager 1 in 1977, but the latter was the first to reach interstellar space in 2012 due to its faster trajectory. His twin brother left our solar system six years later.
Alpha Centauri is home to three stars: Centauri A, Centauri B and Proxima Centauri.
In December of last year, astronomers revealed that they were “closely investigating” a mysterious radio signal from Proxima Centauri, a red dwarf star in the Alpha Centauri system.
Located 4.2 light-years from Earth, Proxima Centauri has two confirmed planets, a Jupiter-like gas giant and a rocky world called Proxima b in its habitable zone.
The signal was spotted by the Parkes Radio Telescope in Australia in April or May 2020 and, unlike previous radio bursts, has not been attributed to a source created by Earth or near Earth.
It’s likely that this signal has a natural explanation, but that hasn’t stopped astronomers hunting aliens from listening more closely than they normally would.
Researchers at the Breakthrough Listen Project – a £70 million initiative to find extraterrestrial life through radio telescopes – said it was one of the most exciting radio signals since the ‘WOW!’ signal in 1977 that led many to speculate that it came from a distant alien civilization.
The ANU study was published in the Journal of the Optical Society of America B.
The project involves deploying thousands of small spacecraft to travel to our nearest galaxy and return photos.
If successful, scientists can determine whether Alpha Centauri, a galaxy about 25 trillion miles away, contains an Earth-like planet.
The catch: It can take years to develop the project, called Breakthrough Starshot, and there’s no guarantee it will work.
The small light-powered vehicles will carry equipment such as cameras and communications equipment.
It involves a ground-based beam of light that propels ultralight nanocrafts — miniature space probes attached to light sails — at speeds of up to 100 million miles per hour.
With such a system, a flyby mission could reach Alpha Centauri in just over 20 years from launch.
Breakthrough Starshot aims to demonstrate a proof of concept for ultra-fast light-powered nanocrafts and lay the groundwork for an initial launch to Alpha Centauri within the next generation. Along the way, the project could bring important additional benefits to astronomy, including exploration of the solar system and detection of asteroids crossing Earth.
Scientists hope that the vehicles, known as nanocraft, will eventually fly at 20 percent the speed of light.
“The thing would look like your cell phone chip with this very thin mesh-like light sail,” NASA’s Pete Worden said.
“It would be about 10.12 feet wide.”
He envisions sending a larger conventional spacecraft with thousands of nanocrafts into orbit and then launching the nanocraft.
If they reach the galaxy and manage to take pictures, it would take about four more years to send them back.