Thanks to Voyager and Cassini, we’ve been able to detect Saturn’s F ring giving birth to moons. Sure, the moons don’t last very long before they disintegrate, but celestial births are still pretty exciting (and they don’t involve any expensive registries or showers). Recently, the ALMA (Atacama Large Millimeter/submillimeter Array) radio telescope (which is actually a set of 66 individual telescopes), received ah high-resolution upgrade that allowed it to record images of planets being born around a young star.
Stars such as our sun are formed when gravity condenses gas and dust clouds into a core. Planets then form inside of those dense clouds, which makes them difficult to observe. However, ALMA, located in the Atacama desert in northern Chile, was able to use longer wavelengths thanks to the antennas recently spaced 15 kilometers apart, which allows for comparisons of signals. These upgrades were implemented in September, and since then, the telescope’s target has been HL Tau, the “infant” star (it’s less than a million years old, after all) in the Taurus constellation roughly 450 light years from Earth. According to research, the new images ALMA obtained are tantamount to me photographing a penny from 70 miles away.
The images provide the most detailed look at the origins of a planet that astronomers have ever seen. The telescope was able to pick up images of dark rings amid the dust and gas. These rings aren’t those that circle a planet like Saturn, but rather, they’re gaps in the dust cloud, cleared away by newborn planets establishing their orbits, like streaks on a muddy windshield.
Because it’s so difficult to observe planetary formation, astronomers usually have to rely on theories and computer simulations, so ALMA’s capabilities to capture newborn planets offer scientists plenty of new insights. Among other things, the findings mean that young stars have the protoplanetary disk of “star stuff” necessary to create planets. Scientists had expected to find a “smooth” disc around HL Tau because of its age. As time goes on astronomers expect to see other cosmic bodies develop, such as asteroids and comets.
Of course, even though ALMA helps scientists observe the birth of planets and star systems, all of this happened a long, long time ago, given the star’s 450 light-year distance from Earth. As Neil deGrasse Tyson pointed out in the awesome Cosmos episode about black holes, studying the universe is a means of time travel.