颁辞苍蝉迟谤耻肠迟颈辞苍听of the world鈥檚听产颈驳驳别蝉迟听谤补诲颈辞听astronomy facility, the SKA听翱产蝉别谤惫补迟辞谤测, begins today. The听辞产蝉别谤惫补迟辞谤测听is a global project 30 years in the making.
With two huge two telescopes, one in听础耻蝉迟谤补濒颈补听补苍诲听the other in听厂辞耻迟丑听Africa, the project will see further into the听丑颈蝉迟辞谤测听of the Universe than ever before.
Astronomers like me will use the telescopes to trace hydrogen over cosmic time聽补苍诲听make precise measurements of gravity in extreme environments. What鈥檚 more, we hope to uncover the existence of complex molecules in planet-forming clouds around distant stars, which could be the early signs of life elsewhere in the Universe.
I have been involved in the SKA聽补苍诲听its precursor telescopes for the past ten years,聽补苍诲听as the chief operations scientist of the听础耻蝉迟谤补濒颈补n telescope since July. I am helping to build the team of scientists, engineers聽补苍诲听technicians who will construct聽补苍诲听operate the telescope, along with undertaking science to map primordial hydrogen in the infant universe.
The SKA听翱产蝉别谤惫补迟辞谤测聽is an intergovernmental organization with dozens of countries involved. The听辞产蝉别谤惫补迟辞谤测听is much more than the two physical telescopes, with headquarters in the UK聽补苍诲听collaborators around the world harnessing advanced computers聽补苍诲听software to tailor the telescope signals to the precise science being undertaken.
The telescope in听厂辞耻迟丑听础蹿谤颈肠补听(called SKA-Mid) will use 197聽谤补诲颈辞听dishes to observe middle-frequency聽谤补诲颈辞听waves from 350 MHz to more than 15 GHz. It will study the extreme environments of neutron stars, organic molecules around newly forming planets,聽补苍诲听the structure of the Universe on the largest scales.
The听础耻蝉迟谤补濒颈补n telescope (SKA-Low), in Western听础耻蝉迟谤补濒颈补, will observe lower frequencies with 512 stations of聽谤补诲颈辞听antennas spread out over a 74-kilometre span of outback.
The site is located within Inyarrimanha Ilgari Bundara, the CSIRO Murchison听搁补诲颈辞-astronomy听翱产蝉别谤惫补迟辞谤测. This name, which means 鈥渟haring sky聽补苍诲听stars鈥, was given to the听辞产蝉别谤惫补迟辞谤测听by the Wajarri Yamaji, the traditional owners聽补苍诲听native title holders of the听辞产蝉别谤惫补迟辞谤测听site.
After decades of planning, developing precursor telescopes聽补苍诲听testing, today we are holding a ceremony to mark the start of on-site听肠辞苍蝉迟谤耻肠迟颈辞苍. We expect both telescopes will be fully operational late this decade.
Each of the 512 stations of SKA-Low is made up of 256 wide-b补苍诲听dipole antennas, spread over a diameter of 35 meters. The signals from these Christmas-tree-shaped antennas in each station are electronically combined to point to different parts of the sky, forming a single view.
These antennas are designed to tune in to low聽谤补诲颈辞听frequencies of 50 to 350 MHz. At these frequencies, the聽谤补诲颈辞听waves are very long 鈥 comparable to the height of a person 鈥 which means more familiar-looking dishes are an inefficient way to catch them. Instead the dipole antennas operate much like TV antennas, with the聽谤补诲颈辞听waves from the Universe exciting electrons within their metal arms.
Collectively, the 131,072 dipoles in the completed array will provide the deepest聽补苍诲听widest view of the Universe to date.
They will allow us to see out聽补苍诲听back to the very beginning of the Universe, when the first stars聽补苍诲听galaxies formed.
This key period, more than 13 billion years in our past, is termed the 鈥渃osmic dawn鈥: when stars聽补苍诲听galaxies began to form, lighting up the cosmos for the first time.
The cosmic dawn marks the end of the cosmic dark ages, a period after the Big Bang when the Universe had cooled down through expansion. All that remained was the ubiquitous background glow of the early Universe light,聽补苍诲听a cosmos filled with dark matter聽补苍诲听neutral atoms of hydrogen聽补苍诲听helium.
The light from the first stars transformed the Universe, tearing apart the electrons聽补苍诲听protons in neutral hydrogen atoms. The Universe went from dark聽补苍诲听neutral to bright聽补苍诲听ionized.
The SKA听翱产蝉别谤惫补迟辞谤测聽will map this fog of neutral hydrogen at low聽谤补诲颈辞听frequencies, which will allow scientists to explore the births聽补苍诲听deaths of the earliest stars聽补苍诲听galaxies. Exploration of this key period is the final missing piece in our understanding of the life story of the Universe.
Closer to home, the low-frequency telescope will time the revolutions of pulsars. These rapidly spinning neutron stars, which fire out sweeping beams of radiation like lighthouses, are the Universe鈥檚 ultra-precise clocks.
Changes to the ticking of these clocks can indicate the passage of gravitational waves through the Universe, allowing us to map these deformations of spacetime with聽谤补诲颈辞听waves.
It will also help us to underst补苍诲听the Sun, our own star,聽补苍诲听the space environment that we on Earth live within.
These are the things we expect to find with the SKA听翱产蝉别谤惫补迟辞谤测. But the unexpected discoveries will most likely be the most exciting. With an听辞产蝉别谤惫补迟辞谤测听of this size聽补苍诲听power, we are bound to uncover as-yet-unimagined mysteries of the Universe. – Reuters
