A trio of Earth-like planets have been found orbiting an ‘ultracool dwarf’ star not too far from our own Sun.

Two of the three planets are in the so-called ‘Goldilocks Zone’ – sitting the right distance from their nearby star and at the right temperature to have liquid water on them.

An international team of astronomers including UNSW’s Dr Duncan Wright contributed to the find.

The scientists estimate that the star, named TRAPPIST-1 after the telescope that spotted it, is just 39 light-years from Earth.

The discovery begs the immediate question; if these planets are so much like ours – could they also harbour life?

The study accompanying the announcement this week certainly suggests that the size and brightness of the host star will be very useful in future studies of the atmospheres of these planets.

Objects like the ‘ultracool dwarf’ that the planets orbit make up about 15 per cent of the population of astronomical objects near the Sun, and are thought to have a large number of terrestrial, potentially habitable planets orbiting them.

The team reports that the ultracool dwarf in question (located just 12 parsecs from Earth) gives off just enough heat to extend its habitable zone to the inner two planets, though it would be fairly dark compared to Earth. The orbit of the third planet appears to be outside the known parameters for supporting life.

The authors note that their observations are not specific about the mass or composition of these planets, and so the ability of the planets to host life remains somewhat unknown.

They say to look out for upcoming data from the Hubble Space Telescope and the James Webb Space Telescope, as it could provide important details about the planets including the possible presence of biomarkers like water, carbon dioxide and ozone.