How does the Parkes radio telescope work?

Decoding the Cosmos: Getting to Know “The Dish”

Ever heard of “The Dish”? I’m talking about the Parkes Radio Telescope, that massive 64-meter radio telescope nestled near Parkes, New South Wales, Australia. It’s been a game-changer in astronomy since way back in 1961, and honestly, it’s still making headlines today. Officially, it’s run by the CSIRO as part of the Australia Telescope National Facility (ATNF), but locals just call it “The Dish.” And get this – in 2020, it even got a Wiradjuri name: Murriyang. Pretty cool, right? Thanks to constant upgrades, Murriyang is still pushing the boundaries of what we know about the universe.

Catching Whispers from the Edge of Space

So, what’s the deal with radio telescopes anyway? Unlike regular telescopes that use light, radio telescopes pick up radio waves from space. Think of them as giant ears listening for the faint murmurs of the cosmos. These radio waves, invisible to our eyes, carry all sorts of secrets. The Parkes telescope is designed to collect and focus these super-weak signals.

The main thing is that enormous, dish-shaped antenna. It’s like a huge satellite dish, but instead of picking up your favorite TV show, it’s grabbing signals from galaxies far, far away. Made of aluminum panels on a lattice, it boasts a collecting area of 3,216 square meters – that’s almost the size of a football field! And why so big? Because those signals from space are incredibly faint. The bigger the dish, the more it can “hear.” These radio waves bounce off the dish and get focused onto a receiver sitting in a cabin suspended right above the center.

Turning Radio Waves into Data We Can Understand

Now, the receiver is where the magic really happens. It takes those weak radio signals and cranks them up – we’re talking amplifying them a million times over! Then, it turns them into electrical signals that computers can understand. Parkes has a whole bunch of different receivers, each tuned to pick up different frequencies. One of the coolest is the Ultra-Wideband Low (UWL) receiver, which can listen to a huge range of frequencies all at once. Another one, the CryoPAF (Cryogenically-cooled Phased Array Feed), is like a wide-angle “radio camera,” capturing a big chunk of the sky at once.

After that, the electrical signals go through some serious processing. This is where scientists work their magic, teasing out the important signals from all the background noise. Think of it like trying to hear a whisper in a crowded room. They’re looking for specific patterns, like the pulses from pulsars or the bursts from fast radio bursts (FRBs). Finally, all that data gets recorded for scientists to analyze later.

Moving with the Stars

The Parkes telescope sits on a special mount called an alt-azimuth mount. Basically, it can swivel around horizontally (azimuth) and move up and down (altitude). This lets it track objects in space as the Earth spins. It’s a pretty impressive feat of engineering, especially when you consider the sheer size and weight of the dish. The engineers even had to design it so that it compensates for the way the dish bends under its own weight when it points in different directions. That way, the radio waves always get focused correctly. It can move pretty quickly too, up to 25 degrees per minute horizontally and 10 degrees per minute vertically.

A History of Amazing Discoveries

Since it started operating in 1961, the Parkes Radio Telescope has been at the heart of some incredible discoveries. Here are just a few:

• Pulsar Paradise: Parkes is famous for finding pulsars, those rapidly spinning neutron stars that act like cosmic lighthouses. In fact, it’s found more than half of all the pulsars we know about! Just in 2021, they discovered over 20 new ones.
• Fast Radio Burst Breakthroughs: Remember those Fast Radio Bursts (FRBs) I mentioned? The very first one was discovered when astronomers looked back at some old Parkes data from 2001!
• Mapping the Galaxies: Parkes has been used to conduct huge surveys of the sky, like the HI Parkes All-Sky Survey, which found over 2500 new galaxies. They’ve even mapped the hydrogen gas in our own Milky Way galaxy!
• Catching Gravitational Waves: The Parkes telescope has played a key role in finding the strongest evidence yet for gravitational waves, those ripples in spacetime predicted by Einstein.
• Moon Landing Hero: Back in 1969, when Neil Armstrong took that first step on the moon, it was the Parkes Observatory that helped relay those live TV images to the world. Pretty amazing, huh?

The Parkes telescope was such a great design that NASA even used it as a model for their Deep Space Tracking Network.

What’s Next for “The Dish”?

The Parkes Radio Telescope isn’t just resting on its laurels. It’s constantly being upgraded with new technology. It’s also a key part of the Square Kilometre Array (SKA), a massive, next-generation radio telescope that will be the biggest and most powerful in the world. With these upgrades, “The Dish” is sure to keep making groundbreaking discoveries for years to come. It’s an exciting time to be an astronomer!