"You always want to observe phenomena on all wavelengths possible," says Astronomy Australia chair Orsola De Marco.

"The European Southern Observatory that we are trying to be members of is the largest observatory on Earth - we're not talking about space telescopes."

Down Under may be the perfect place for radio astronomy with some of the quietest and most remote locations on the planet, which suits the $3 billion Square Kilometre Array (SKA) being built in remote Western Australia.

But optical astronomy is on a different wavelength. To function perfectly, it needs cold, dry air and height.

That's why the ESO's newest telescope is being built in Chile's Atacama Desert to take the twinkle out of stars and get an accurate reading on space and time.

"The reason size matters is that the bigger the mirror, the more light you get and you can see fainter and fainter stars, and more accurately," Professor De Marco says.

"It's going to do things we just dream about right now, like finding Earth-like planets far away from the solar system.

"We can start understanding what their atmospheres look like and understanding if life is on that planet."

Nearby galaxies and their stars will also be in sight, meaning astronomers can start to understand if the universe worked the same way seven billion years ago.

"There's discoveries that we won't have predicted," Prof De Marco says.

"Australia does extremely well in astronomy for the size of the country and economy, and so we just want to keep going with an observatory that's at the cutting edge and remain at the cutting edge for the next decade or more."

The southern part of the globe also has a better view than in Europe because it points to the galactic centre, she says.

A competing United States-led project, the Thirty Meter Telescope, has run into environmental controversy because of its location on the summit of Hawaii's tallest mountain Mauna Kea, which is considered tapu or sacred.

The Extremely Large Telescope or ELT is on track to go "on sky" in 2027 and 2028, at least seven years before any competitors.

"If you go to one of these observatory sites we operate in the Atacama desert ... you'll get immediately captivated, it's really mind blowing," the organisation's director-general Xavier Barcons says.

"Astronomy is a science that needs a multiplicity of tools to make progress but it takes time for the scientific community to engage - you cannot go the first day and get immediate access, you need to build your strengths.

"That is why the opportunity is on the table now."

Professor Barcons recently met with officials and researchers in Perth, Canberra and Sydney as Australia's limited partnership is due to expire in 2027.

"Australia has a lot of radio astronomy expertise in the west and optical expertise in the east, and for me and for everyone this is part of the same story and science possibilities," he says.

The former coalition government signed a 10-year deal in 2017 that cost $129.2 million, which provided access to several optical telescopes at ESO's Paranal Observatory in northern Chile.

The organisation also runs the largest radio observatory in the world, which is different to SKA being developed in WA because it works at higher frequencies and targets different types of astronomical phenomena.

The Atacama Large Millimeter/submillimeter Array (ALMA) is the most complex astronomical observatory ever built on Earth, capturing never-before-seen details about the very first stars and galaxies, and directly imaging the formation of planets.

But ALMA has been up and running for more than 10 years and a significant program of equipment upgrades is needed.

"We know Australia has skills to be part of the development and this is happening now," Prof Barcons says.

The Astralis consortium of Macquarie University, Australian National University and University of Sydney is already part of an international group building an adaptive optics system that will provide images up to three times sharper than the Hubble Space Telescope.

Looking at very faint objects, the Multi-conjugate-adaptive-optics-Assisted Visible Imager and Spectrograph, or MAVIS, will have the capability to remove blur caused by turbulence in Earth's atmosphere.

In return for building it, the consortium will get guaranteed time with the instrument at the Paranal Observatory, as well as a financial contribution from ESO for its hardware.

"But we think the horizon is much, much bigger and there are opportunities beyond what we are achieving today," Prof Barcons says.

The new ELT will be 2635 metres above sea level in one of Earth's driest places with annual rainfall of less than 10 millimetres.

In contrast, Australia's much smaller Siding Spring Observatory, on the edge of the Warrumbungle National Park near Coonabarabran in NSW, sits at 1165m with an annual rainfall of 720mm and is vulnerable to bushfires.

The new observatory in Chile will also be 15 times sharper than the Hubble telescope that changed human understanding of the universe, with the additional benefit of not having to be launched into space.

The horizon could be unlimited for a joining fee of $450 million, spread over 10 years.

But a formal invitation for full membership is yet to be issued to the Albanese government and no ministerial level talks have been held.

Australian Associated Press