what is Starlink satellites: Facts, tracking and impact on astronomy

1) How many Starlink satellites are in orbit?
 As of March. 28, 2025, there are 7,135 Starlink satellites in orbit, of which 7,105 are working, according to Astronomer Jonathan McDowell, who tracks the constellation on his website.
 2) How to see starlink satellites ?
 Starlink satellites orbit approximately 342 miles (550 kilometers) above Earth and put on a spectacular show for observers as they move across the sky.
 3) Starlink coverage
 To see current Starlink internet availability around the world, and if it's available where you are, Starlink has an interactive map detailing locations where Starlink internet is available, which areas are on the waitlist as well as areas that are "coming soon".
 4) The history of Starlink
 SpaceX's satellite internet proposal was announced in January 2015.  Though it wasn't given a name at the time, CEO Elon Musk said that the company had filed documents with international regulators to place about 4,000 satellites in low Earth orbit.
 The U.S.  Federal Communications Commission (FCC) has granted SpaceX permission to fly 12,000 Starlink satellites, and the company has filed paperwork with an international regulator to loft up to 30,000 additional spacecraft.
 To put that into perspective, as of Nov. 7, 2022, only 14,450 satellites have been launched in all of history with 6,800 currently active according to the European Space Agency (ESA).
 The first 60 Starlink satellites launched on May 23, 2019, aboard a SpaceX Falcon 9 rocket.  The satellites successfully reached their operational altitude of 340 miles (550 kilometers).
 5) Starlink's impact on astronomy
 Within days of the first 60-satellite Starlink launch, skywatchers spotted a linear pearl string of lights as the spacecraft whizzed overhead in the early morning.  Web-based guides showed others how to track down the spectacular display.
 The International Astronomical Union (IAU) expressed concerns in a statement released in June 2019.  "Satellite constellations can pose a significant or debilitating threat to important existing and future astronomical infrastructures, and we urge their designers and deployers as well as policy-makers to work with the astronomical community in a concerted effort to analyze and understand the impact of satellite constellations," the statement said.
 In April 2021, Thomas Schildknecht, the deputy director of the Astronomical Institute of the University of Bern, who represents Switzerland in the IAU, said at the European Space Agency's space debris conference that the union was calling on the United Nations to protect pristine night sky as cultural heritage against the uncontrolled expansion of megaconstellations.
 In a report released in October 2022, the American Astronomical Society (ASS) likened the impact of megaconstellations on astronomy to light pollution.  The report said the sky may brighten by a factor of two to three due to the diffuse reflection of sunlight off the spacecraft.