Pyxis interferometry telescopes could help find Earth-like worlds

A long thin tube with lenses or mirrors? Perhaps a large, white dome on a mountaintop?

Two years ago in our Sunday Space column, we ran a six-part series on telescopes.

None of the telescopes we mentioned were based at Mt Stromlo Observatory, here in Canberra, because during the terrible 2003 bushfires all but one of our telescopes burnt down.

Well, we are now close to finally having an operational telescope that astronomers on the mountain can use for astronomy research purposes, though it might not look like what you'd expect.

As a side note, Mt Stromlo does have other telescopes, but these are primarily used for outreach purposes, or non-astronomy-based research such as laser communications or tracking space junk.

The telescope in question, named Pyxis after the southern constellation, is in fact a set of three, small robotic platforms located in the carpark of the observatory that can move around autonomously.

Two of the robots contain telescopes, which collect and reflect light from stars towards a central robot that combines the light and produces scientific information.

This technique is known as interferometry, which we have covered in previous Sunday Space articles.

The benefit of having multiple, small telescopes is that you can achieve incredible on-sky resolution without needing to build mirrors that are tens, if not hundreds of metres across - instead you separate the telescopes by the equivalent mirror diameter.

The downside though is that Pyxis cannot see very faint things, as it only has the total collecting area of a single 13cm diameter telescope.

It is a worthwhile trade-off though, as the prime targets for Pyxis are bright stars nearing the end of their lives. These stars have huge amounts of dust surrounding them, and pulsate strongly as they lose a lot of their stellar material.

Observing such detail around stars is nearly impossible without utilising interferometry.

At the same time, Pyxis is also being used as a demonstrator for a future space mission.

This is why the telescopes are mounted on robots - these robots are placeholders for satellites.

Eventually we hope to demonstrate that interferometry can be done in space using multiple satellites flying together in formation; an important goal as this technique is our best chance at looking for other habitable Earth-like exoplanets.

MORE SUNDAY SPACE:

It costs a lot of money to send telescopes to space, and so it is best to make sure we can make these telescopes work together on the ground first.

One of my favourite things about Pyxis is that despite being a very complex mix of robotics and optics, it is still distinctly Australian.

A lot of the parts were sourced from Bunnings (the robots move around on plywood floorboards) and utilise 3D printing from the ANU Makerspace. I sometimes refer to Pyxis as "the hardware store interferometer".

So here's to Pyxis, a set of robots in the Mt Stromlo carpark searching for dust around dying stars and aiming to pave the way for a space mission to find other Earth-like worlds.