Are we alone? James Webb space telescope can see back 13.5 billion years
SCIENTISTS have long scanned the cosmos searching for answers to the questions ‘are we alone’ and ‘how did we get here’. Answers might come soon.
EVER since humans began walking upright and well before the 16th century Italian physicist and astronomer Galileo first identified Jupiter’s moons, man has gazed skywards at night and pondered the question, “Are we alone?”
Scientists have been desperately scanning the cosmos for the past five centuries seeking an answer to the fundamental mystery of the universe, but so far they have found no evidence of any extra terrestrial life forms.
That could all change in late 2018 when the most powerful space telescope ever developed is launched on a French Ariane 5 rocket from a commercial spaceport in French Guiana, South America.
With an 18-metre by 12-metre, five-layer, flexible sun shield, the system will be folded up to fit inside a five-metre wide rocket and will unfurl like a butterfly emerging from its cocoon once it reaches orbit.
The James Webb space telescope, named for James Webb the second administrator of the National Aeronautics and Space Administration (NASA), is an $8 billion, 25 square metre, gold coated beryllium instrument that will orbit 1.5 million kilometres from Earth. It is seven times bigger than the Hubble telescope and will peer back in time to examine light in the infra red spectrum that began its 300,000 kilometres a second journey more than 13.5 billion years ago.
PICTURES: THE JAMES WEBB SPACE TELESCOPE
That will take scientists out to the edge of the “known universe” and as well as detecting any other potential life forms it will establish if that “edge” is indeed where the universe ends.
With such vast distances involved it is difficult to comprehend that the universe actually has an ‘end’.
Such huge figures are impossible for the human brain to comprehend, but astrophysicists around the globe are extremely excited about the prospects of a major breakthrough with the Webb telescope. And it will be for the use of all mankind and any scientist anywhere on the globe will be able to apply for time on the instrument.
The telescope will use its superb angular resolution and near-infra-red instruments to discover and study planetary systems similar to our own, analyse the molecular composition of their atmospheres, and directly image Jupiter-size planets orbiting nearby stars.
In addition to the “are we alone?” question the instrument will also examine human kind’s other great mystery: “How did we get here?”
The project is a partnership between NASA, the European Space Agency and the Canadian Space Agency. American aerospace giant Northrop Grumman is the prime contractor and the company is building both the spacecraft bus, or the spaceship, and the sun shield that will protect the telescope and keep it operating at a temperature of minus 195 degrees Celsius. Under subcontract to Northrop Grumman, Ball Aerospace built the mirror.
The spacecraft has 250,000 individual parts and most of them have been individually designed, engineered and manufactured either at Northrop’s nondescript space facility in Los Angeles or at other laboratories around the US.
Northrop’s chief project engineer Dr Jonathan Arenberg has been working on the Webb telescope for nine years and he told News Corp Australia that he had pulled more ‘all nighters’ on this job that at any time during his extensive university studies.
During a tour of the LA facility last week, the remarkably plain-speaking Dr Arenberg told News Corp that the Webb telescope would allow scientists to actually study how galaxies assembled and how stars and planets were born.
He said the scientists had presented the engineers with the greatest problem they had ever seen.
“The telescope is large and optically exquisite and we will be able to see many things that we have never seen before,” he said.
“These will be faint signals from the beginning of time. Using infra red we can peer into the stellar nurseries for a clearer picture of the stars.”
Its mirrors are so perfect that they had an atom stripped off at a time to perfect the surface and each of the 18 mirrors on the telescope has seven motors behind it to fine tune it.
“This machine is incredible,” Dr Arenberg said.
He said the biggest challenge for engineers was getting the instrument cold and keeping it cold and then preventing leaks. With a temperature differential of more than 200 degrees Celsius between the bottom of the sun shield and the top of the telescope the challenge is enormous for what he called a “hi-tech parasol’’.
“The shield hides the sun, the Earth and the moon and remains out of the Earth’s shadow,” he said.
Stability is vital for such minuscule observations.
“It is like opening a camera shutter for 10 days at a time,” Dr Arenberg said.
The launch of the Webb telescope will coincide with the construction of the world’s biggest ground-based radio telescope, the $3 billion Square Kilometre Array (SKA) in Western Australia, New Zealand and South Africa. It is due to be in operation a year after the Webb reaches its orbit. It will be 50 times more sensitive than any other radio telescope on Earth and will survey the sky more than ten-thousand times faster than ever before.
Together the Webb space telescope and the SKA represent the biggest leaps forward in astrophysics in human history.
If all goes well the James Webb will take about 180 days to fully deploy and should be fully operational by April 2019.
Before then the systems will be tested and retested and the entire structure will be shaken two to three times harder than what it will suffer during its violent launch.
“We test everything excessively,” Dr Arenberg said.
For astrophysicist Blake Bullock the launch of the James Webb will be the most exciting moment ever in her chosen field. It will also signal the start of some of the most detailed cooperation ever between the disciplines of biology, chemistry, physics and engineering as they endeavour to reach the edge of astrophysics.
And what of the big question?
“Given the size of the mirror we can only reach so far ... but I hope in my hearts of hearts that we find a signature of one of life’s biomarkers out there,” she said.
“But I also know that if we don’t it’s not the end. We are already thinking of designs for that next generation opportunity. We want to be side by side with NASA ... to build the next generation system.
“Even if we did find a signature we would have to go beyond.
“I have my fingers crossed.”
Ms Bullock said the big question about whether or not humanity was alone in the universe made some people feel small or overwhelmed.
“But to feel that at this point in our lives we have come to this point ... that the human race has evolved all these technologies to converge to a point where we now can be the ones to see the first answers to these questions. To me that is a really good feeling.
“It feels like it’s a special time in our evolution that we are really getting answers to these big questions we have been asking since we evolved.”
She said going to work every day with a team of people who were the best in the world at what they did, there was no punching the clock.
“People come here and feel like they are really going to change the world, they are going to change history. Not everyone gets to say that.”
She said that if signs of life were detected early in the telescope’s mission that would become the focus of its planned five-year lifespan.
*Ian McPhedran travelled to the US as a guest of Northrop Grumman.
Huge Captain Cook find changes everything
The mystery of Captain Cook’s lost ship has finally been solved, ending a 250-year-long search.
Harrowing footage of shark attack victim
Bodycam footage from the scene of a shark attack that left “blood everywhere” shows medics rushing to save a girl’s life at a holiday hotspot.
Shock find under pyramids stuns the world
Archaeologists are stunned after discovering what they believe could be an ancient city under the pyramids of Giza.