Space discoveries to be shared

Otago Daily Times

18-06-2025

Stargazing dreams first kindled in childhood will soon be shared in Dunedin.
American astrophysicist and former Nasa communicator Dr Michelle Thaller arrives this month as the special guest of the New Zealand International Science Festival, which opens on June 28.
During a series of talks she will share nearly three decades of space discoveries, ranging from neutron stars to tantalising hints of possible life on other planets.
Dr Thaller's career began with the pioneering infrared Spitzer Space Telescope at Nasa's Jet Propulsion Laboratory.
"We had never had a telescope that looked at the universe quite that way before," Dr Thaller said.
"It was literally a new set of eyes, we were detecting light and creating images, we just never had seen anything like it."
Stars form inside vast clouds of gas and dust that block light, so it was previously impossible to see within them.
By tracing heat rather than visible light, the observatory peered inside and caught the moment new solar systems formed.
"It is just incredible to see these discoveries coming in, your jaw drops every time."
She later served as assistant director of science, for communication, at Nasa's Goddard Space Flight Centre, a role that involved translating findings such as neutron stars, the collapsed remnants of giant stars.
"They are only about 30km across, they are tiny little things but they have about the mass of two times the sun."
Despite scientists studying thousands of these "monsters", it is still not fully understood how they work because there is no physics to describe such mass packed into so small a volume; ordinary atoms could not withstand those conditions.
"That is so much gravity in so small a place that it actually bends space and time and when you look at a neutron star, you can see the back of it as well as the front of it because light is actually bending around."
"There is so much gravity and so much mass there it is actually warping space and time so that light travels from the back side towards you as well."
The discovery that had eluded her during nearly 30 years at Nasa was solid scientific evidence of life beyond Earth.
"With our Mars rovers we have seen some chemical signals that could be life, but we are not sure, there is no smoking gun."
There have been close calls, such as a planet about 100 light-years away observed with the new James Webb Space Telescope.
"There was this tiny little signal that actually got stronger over time that we thought could be what we would call a biosignature, something that is only produced by biology."
However, recent analysis has suggested it may be something else.
"It was definitely an organic molecule, definitely a carbon-based molecule, the kind that is our chemistry.
"But we had to sort of slow our hopes down a little bit, it wasn't quite ready yet." Festival
New Zealand International Science Festival
June 28 — July 6
Visit scifest.org.nz for details
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