A free-range floating world
Astronomers have discovered a new”vagabond world” — a kind of world that ﬂoats openly through the Milky Way, untethered to any star, reports The Times. Sightings are incredibly rare (only about half a dozen have been detected) and the latest one is the smallest yet: it is thought to be around the size of Mars. Astronomers say they might just have been really fortunate to ﬁnd it, but it is possible our Milky Way is really teeming with those planets. There could, they say, be billions of them — but they are very tough to detect. Unlike other planets outside our solar system, they cannot be spotted by the dimming they cause when passing their star, as they do not orbit a star; nor do they give off radiation. Therefore, their presence must be inferred from a phenomenon known as”gravitational microlensing”.This occurs when the gravity of a large celestial object behaves as a magnifying glass on the light emitted by means of a background star. Finds according to gravitational microlensing are really rare, since they are contingent on the thing, telescope and source being in perfect alignment.