ALMA will watch a gas cloud
spiral into the black hole at the center of the Milky Way.By the end of the year, when all of its dishes are online, ALMA will have 100 times the imaging resolution of any scope looking at very short radio waves, which emanate from cool, dark sources such as interstellar dust and from bright, distant galaxies. But it's already had some impressive finds. In March, astronomers discovered surprising numbers of "starburst" galaxies, where new stars were forming a billion years earlier than anyone thought. This summer, they might have found evidence of dust traps near stars that help the formation of planets, asteroids, and comets. And eventually, ALMA will watch a gas cloud spiral into the black hole at the center of the Milky Way, look for molecular signs of life on faraway worlds, and measure the location and density of the mysterious substance scientists call dark matter—all from a high desert on planet Earth.