In the constellation Cetus, Tau Ceti is a star visible to the naked eye from both hemispheres. The star Tau Ceti has been exciting researchers lately. This star is believed by many to host planets with life-friendly conditions. In a world hoping to discover living beings on other planets, and/or potential other homes for humans of the future, news like this always creates a buzz. Although these planets have not yet been proven to exist, the announcement is especially exciting because Tau Ceti is relatively near Earth-just twelve light years away-and thus easier to reach in the future.
Earth's sun and Tau Ceti
Tau Ceti is a star similiar to Earth's own sun in both size and luminosity. It appears to have planets sized something like those of that sun, as well. There are five identified planets, but there may be more. This planetary system is remarkable for its low mass, being "the lowest-mass planetary system ever detected." One of them is ideally situated from its sun to allow ideal temperatures for life development. When similar conditions seem to be present in other galaxies, Earth-dwelling scientists have reason to look for life on other planets.
Tau Ceti's planets
"The quintet includes planets between two and six times the Earth's mass, with periods ranging from 14 to 640 days. One of them, dubbed HD 10700e, lies about half as far from Tau Ceti as Earth is from the Sun," but as Tau Ceti is a little less bright and a little less big than the sun, HD 10700e exists in the habitable zone. This means the planet is located neither too close to nor too far from Tau Ceti to have liquid water, which is essential to known life. The discovery of planets around Tau Ceti is the success of an international team of astronomers from the United States, Chile, United Kingdom and Australia. More than six thousand observations of new spectographs and re-analysis of old ones contributed. This ream of data and ground-breaking methodology proved eye-opening for the astronomers. By allowing them to pick up signals that were half as powerful as before, they were in a much better position to detect small planets.
A word of caution to the inhabitants of HD 10700e
Those tempted to jump for joy at the discovery of a Sol-like sun and a probable habitable-zone planet around Tau Ceti should, perhaps, be cautious in their optimism and restrain their enthusiasm. While potential life may exist there currently, or have been present in the past, cosmic drama seems commonplace here. A quick crash with a space object, such as an asteroid or comet, could make that life bite the proverbial space dust in a millisecond. This is asteroid territory, and Tau Ceti's large belt of them has an impressive "10 times more asteroids and comets than our own solar system." Asteroids are not always bad for life, though. "Asteroids can also bring water to a planet, which can be beneficial."