Once a week.
Subscribe to our weekly newsletter.
We’ve mapped a million previously undiscovered galaxies beyond the Milky Way. Take the virtual tour here.
See the most detailed survey of the southern sky ever carried out using radio waves.
Astronomers have mapped about a million previously undiscovered galaxies beyond the Milky Way, in the most detailed survey of the southern sky ever carried out using radio waves.
While past surveys have taken years to complete, ASKAP's RACS survey was conducted in less than two weeks — smashing previous records for speed. Data gathered have produced images five times more sensitive and twice as detailed as previous ones.
What is radio astronomy?
Modern astronomy is a multi-wavelength enterprise. What do we mean by this?
Well, most objects in the universe (including humans) emit radiation over a broad spectrum, called the electromagnetic spectrum. This includes both visible and invisible light such as X-rays, ultraviolet light, infrared light and radio waves.
To understand the universe, we need to observe the entire electromagnetic spectrum as each wavelength carries different information.
Radio waves have the longest wavelength of all forms of light. They allow us to study some of the most extreme environments in the universe, from cold clouds of gas to supermassive black holes.
Long wavelengths pass through clouds, dust and the atmosphere with ease, but need to be received with large antennas. Australia's wide open (but relatively low-altitude) spaces are the perfect place to build large radio telescopes.
We have some of the most spectacular views of the centre of the Milky Way from our position in the Southern Hemisphere. Indigenous astronomers have appreciated this benefit for millennia.
A stellar breakthrough
Radio astronomy is a relatively new field of research, dating back to the 1930s.
The first detailed 30cm radio map of the southern sky — which includes everything a telescope can see from its location in the Southern Hemisphere — was Sydney University's Molonglo Sky Survey. Completed in 2006, this survey took almost a decade to observe 25% of the entire sky and produce final data products.
Our team at CSIRO's Astronomy and Space Science division has smashed this record by surveying 83% of the sky in just ten days.
With the RACS survey we produced 903 images, each requiring 15 minutes of exposure time. We then combined these into one map covering the entire area.
The resulting panorama of the radio sky will look surprisingly familiar to anyone who has looked up at the night sky themselves. In our photos, however, nearly all the bright points are entire galaxies, rather than individual stars.
Take our virtual tour below.
Astronomers working on the catalogue have identified about three million galaxies — considerably more than the 260,000 galaxies identified during the Molonglo Sky Survey.
Why do we need to map the universe?
We know how important maps are on Earth. They provide crucial navigational assistance and offer information about terrain which is useful for land management.
Similarly, maps of the sky provide astronomers with important context for research and statistical power. They can tell us how certain galaxies behave, such as whether they exist in clusters of companions or drift through space on their own.
Being able to conduct an all-sky survey in less than two weeks opens numerous opportunities for research.
For example, little is known about how the radio sky changes over timescales of days to months. We can now regularly revisit each of the three million galaxies identified in the RACS catalogue to track any differences.
Also, some of the largest unanswered questions in astronomy relate to how galaxies became the elliptical, spiral, or irregular shapes we see. A popular theory suggests large galaxies grow via the merger of many smaller ones.
But the details of this process are elusive and difficult to reconcile with simulations. Understanding the 13 billion or so years of our universe's cosmic history requires a telescope that can see across vast distances and accurately map everything it finds.
The giant Centaurus A galaxy was one elliptical galaxy captured in the RACS survey. Although more than ten million light years away, it's one of the closest radio galaxies to Earth. You can see its 'intensity' represented by different colours. (CSIRO, Author provided)
High technology putting new goals within reach
The CSIRO's RACS survey is an amazing advance made possible by huge leaps in space tech. The ASKAP radio telescope, which became fully operational in February last year, was designed for speed.
CSIRO's engineers developed innovative radio receivers called "phased array feeds" and high-speed digital signal processors specifically for ASKAP. It's these technologies that provide ASKAP's wide field of view and rapid surveying capability.
Over the next few years, ASKAP is expected to conduct even more sensitive surveys in different wavelength bands.
In the meantime, the RACS survey catalogue is greatly improving our knowledge of the radio sky. It'll continue to be a key resource for researchers around the world.
Full resolution images can be downloaded from the ASKAP data archive.
- Is Our Galaxy in a Backwater of the Universe? - Big Think ›
- There may be millions of habitable planets in our galaxy - Big Think ›
The father of all giant sea bugs was recently discovered off the coast of Java.
- A new species of isopod with a resemblance to a certain Sith lord was just discovered.
- It is the first known giant isopod from the Indian Ocean.
- The finding extends the list of giant isopods even further.
The ocean depths are home to many creatures that some consider to be unnatural.<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU2NzY4My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYxNTUwMzg0NX0.BTK3zVeXxoduyvXfsvp4QH40_9POsrgca_W5CQpjVtw/img.png?width=980" id="b6fb0" class="rm-shortcode" data-rm-shortcode-id="2739ec50d9f9a3bd0058f937b6d447ac" data-rm-shortcode-name="rebelmouse-image" data-width="1512" data-height="2224" />
What benefit does this find have for science? And is it as evil as it looks?<div class="rm-shortcode" data-media_id="7XqcvwWp" data-player_id="FvQKszTI" data-rm-shortcode-id="8506fcd195866131efb93525ae42dec4"> <div id="botr_7XqcvwWp_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/7XqcvwWp-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/7XqcvwWp-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/7XqcvwWp-FvQKszTI.js"></script> </div> <p>The discovery of a new species is always a cause for celebration in zoology. That this is the discovery of an animal that inhabits the deeps of the sea, one of the least explored areas humans can get to, is the icing on the cake.</p><p>Helen Wong of the National University of Singapore, who co-authored the species' description, explained the importance of the discovery:</p><p>"The identification of this new species is an indication of just how little we know about the oceans. There is certainly more for us to explore in terms of biodiversity in the deep sea of our region." </p><p>The animal's visual similarity to Darth Vader is a result of its compound eyes and the curious shape of its <a href="https://lkcnhm.nus.edu.sg/research/sjades2018/" target="_blank" rel="noopener noreferrer dofollow" style="">head</a>. However, given the location of its discovery, the bottom of the remote seas, it may be associated with all manner of horrifically evil Elder Things and <a href="https://en.wikipedia.org/wiki/Cthulhu" target="_blank" rel="dofollow">Great Old Ones</a>. <em></em></p>
A supernova exploded near Earth about 2.5 million years ago, possibly causing an extinction event.
- Researchers from the University of Munich find evidence of a supernova near Earth.
- A star exploded close to our planet about 2.5 million years ago.
- The scientists deduced this by finding unusual concentrations of isotopes, created by a supernova.
This Manganese crust started to form about 20 million years ago. Growing layer by layer, it resulted in minerals precipitated out of seawater. The presence of elevated concentrations of 60 Fe and 56 Mn in layers from 2.5 million years ago hints at a nearby supernova explosion around that time.
Credit: Dominik Koll/ TUM
Researchers devise a record-breaking laser transmission that avoids atmospheric interference.
- Researchers from Australia and France team up for a record-breaking laser transmission.
- The new technique avoids atmospheric interference.
- It can be used to test aspects of Einstein's theory of relativity and advance communications.
Scientists achieved the most stable transmission of a laser signal through the atmosphere ever made, beating a world record. The team managed to send laser signals from one point to another while avoiding interference from the atmosphere. Their very precise method can allow for unprecedented comparisons of the flow of time in separate locations. This can enable scientists to carry out new tests of Einstein's celebrated theory of general relativity, and have wide applications across different fields.
For the record transmission, the researchers combined phase stabilization technology with advanced self-guiding optical terminals. They used two identical phase stabilization systems, which had their transmitters located in one building while receivers were in another. One system used optical terminals to send the optical signal over a 265 m free-space path between the buildings. Another system transmitted using a 715 m-long optical fiber cable, essentially to keep tabs on the performance of the free-space link.. The terminals were outfitted with mirrors to prevent interference like phase noise and beam wander.
The scientists hailed from Australia's International Centre for Radio Astronomy Research (ICRAR) and the University of Western Australia (UWA), as well as the French National Centre for Space Studies (CNES) and the French metrology lab Systèmes de Référence Temps-Espace (SYRTE) at Paris Observatory.
The study's lead author Benjamin Dix-Matthews, a Ph.D. student at ICRAR and UWA, highlighted the innovation and potential of their technique. "We can correct for atmospheric turbulence in 3-D, that is, left-right, up-down and, critically, along the line of flight," said Dix-Matthews in a press release. "It's as if the moving atmosphere has been removed and doesn't exist. It allows us to send highly stable laser signals through the atmosphere while retaining the quality of the original signal."
Block diagram of the experimental link that shows two identical phase stabilization systems on the CNES campus. Both of the systems have their transmitter in the Auger building (local site), and both receivers are located in the Lagrange building (remote site). One transmits the optical signal over a 265 m free-space path in-between the buildings while utilizing tip-tilt active optics terminals. The other transmits using 715 m of optical fiber.
Credit: Dix-Matthews, Nature Communications
Dr. Sascha Schediwy, ICRAR-UWA senior researcher, envisioned numerous applications for their technology, whose precise performance beats even the best optical atomic clocks. Putting one of these optical terminals on the ground while another one is on a satellite in space would help the exploration of fundamental physics, according to Schediwy. Other applications could extend to testing Einstein's theories with greater precision as well as understanding the time-related changes of fundamental physical constants and making advanced measurements in earth science and geophysics.
Optical communications, a field that that utilizes light for sending information, could also benefit. The new tech can improve its data rates by "orders of magnitude," thinks Dr. Schediwy. "The next generation of big data-gathering satellites would be able to get critical information to the ground faster," he added.
Check out the new study in Nature Communications.