SPEAKER’S REPORT: U.S.Q., Toowoomba and Life Elsewhere

Guest speaker at the November meeting Jonti Horner, Vice Chancellor’s Senior Research Fellow, gave a talk entitled “U.S.Q., Toowoomba and Life Elsewhere”. The idea of life outside Earth started with the erroneous idea that there were canals on Mars. But there are several places in the Solar System that have the necessary requirements for life: a solvent like water, nutrients; and energy, e.g. our Sun. Europa, one of Jupiter’s moons, has an ocean about 100 kilometres deep, with volcanism on the bottom, but there is an outer layer of ice 10-20 kilometres thick that prevents us from detecting any possible life below.

In the past Mars had lots of water, and even now there is ice water underground under intense pressure. Any life there would be primitive life like bacteria. But exoplanets, i.e. planets around other stars, are the main emphasis now. These can be detected in a number of ways. The presence of a planet produces a slight wobble in the motion of a star. And there is a tiny dimming of a star when a planet transits in front of it. Spectral lines, representing the emission lines of elements in a star, are subject to the Doppler effect caused by the star and planet moving towards and away from Earth in their orbit.

Pulsars are ultra-dense neutron stars, which are spinning very rapidly. The pulsar’s radiation is focused into a beam by the pulsar’s strong magnetic field. This blip is regular, but the presence of a planet causes it to occur earlier or later. The Kepler Space Telescope, which was launched in order to detect exoplanets, surveyed only one patch in the sky. NASA’s Transiting Exoplanet Survey Satellite, when launched, will target all the brightest stars in all of the night sky. Exoplanet detection needs more telescopes. MINERVA is a four-telescope array in Arizona looking for exoplanets in the northern hemisphere. USQ is building a complementary MINERVA multi-telescope facility at Mount Kent. The number of exoplanets discovered has been increasing exponentially, and they have been finding more that resemble Earth.

(Report by Mary Petr)