The Oort Cloud is a hypothetical region of space surrounding the Solar System, extending far beyond the furthest reaches of the Kuiper Belt. It is believed to be the source of long-period comets. Dangers associated with the Oort Cloud include the possibility of gravitational perturbations from passing stars or galactic tides, which could potentially dislodge comets from their orbits and send them towards the inner Solar System, posing a threat to Earth and other planets. However, the likelihood of such an event occurring is extremely low.
Tau Ceti, Latinized from τ Ceti, is a single star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of just under 12 light-years (3.7 parsecs) from the Solar System, it is a relatively nearby star and the closest solitary G-class star. The star appears stable, with little stellar variation, and is metal-deficient (low in elements other than hydrogen and helium) relative to the Sun.
Tau Ceti Observation data