PHILADELPHIA (AP) — A string of lights that lobbed across the night sky in parts of the United States over three nights earlier this week had callers frantically calling TV stations from Texas to Wisconsin and speculating that a fleet of UFOs was coming. But the string of lights that was actually a series of relatively low-flying satellites launched by Elon Musk’s SpaceX as part of its Starlink internet service plan. And it had amateur stargazers and professional astronomers lamenting the industrialization of space. Professional astronomers say the company has voluntarily worked to significantly reduce the light reflected by its satellites, but they hope for more progress before thousands more satellites are launched into the night sky.