Skywatch: Crowded space

Yahoo

11-05-2025

A little over 240 years ago, birds were the only things that could fly above the ground untethered without eventually falling. That all changed in 1783 when Jean-François Pilâtre de Rozier and François Laurent d'Arlandes made the first successful hot-air balloon flight over Paris. Just think about what must have been going through their heads when they saw the Earth from above. No humans had ever had a bird's-eye view like that before and lived to tell about it!
It took until 1903 for the next major aviation feat to be accomplished when the Wright brothers flew the first airplane in the skies just south of Kitty Hawk, N.C. Fifty-four years later, the Soviet Union put the first human-made satellite, Sputnik 1, in orbit around the Earth, and four years after that, the Russians launched the first human-occupied satellite, Vostok 1, with astronaut Yuri Gagarin aboard.
Since that time over 11,000 satellites have been launched into orbit, with and without people aboard. Many of those satellites have long since burned up in the Earth's atmosphere because of orbital decay. Others, mainly occupied by humans, have successfully re-entered the atmosphere to either land on the ground or splash down in the ocean. There is a fantastic website, www.N2YO.com, that tracks objects in the sky. If you go to their search engine and type in Vanguard 1, you can see that it is in the first position of one of the first U.S. satellites launched in 1958 and is still in orbit 67 years later! When you explore N2YO, you can get orbital data on thousands in orbit. However, many of those satellites have stopped functioning, and many are actually spent rocket stages that boosted satellites into orbit. It's crowded above the Earth, but there's still a lot of room left.
The really cool thing is that stargazers can see many of these satellites. If you're intently studying the night sky looking for constellations and observing with binoculars or a telescope, it's hard to go more than a half-hour without seeing a satellite zipping along. Most satellites move from west to east, but some are in polar orbits. The best time to see them is in the early evening for a couple of hours after evening twilight or a couple of hours before the start of morning twilight. That's because satellites have to reflect sunlight to be visible. Even if satellites had huge spotlights mounted on them, you'd never see them. They're just too high up. Just before morning twilight, and for a little while after evening twilight, there's no direct sunlight available to us on the ground, but high in space there's still enough sunlight to bathe satellites, sending secondhand sunshine our way. During the middle of the night the sun is entirely behind the Earth, so all satellites pass over in total darkness.
By far, the easiest satellite to spot is the International Space Station. It's as bright as a jetliner passing over. Because of that many people see it all the time and figure it's a jet. Its first component or module was launched in 1998, and the station was completed in 2011. It's longer than a football field! What makes it so bright are the eight solar panels that are over 100 feet long and nearly 40 feet wide! They bounce a heck of a lot of secondhand sunshine our way!
The ISS orbits the Earth about every 90 minutes, traveling at almost 5 miles a second. It moves in a general direction from west to east across the dome of the sky. The ISS doesn't pass over the same location each orbit. That's because of the nature of its orbit and the fact that Earth is rotating. There can be stretches of nights when it doesn't pass over at all. That's why you need to have an app or a website that will let you know where and when to look. Some apps will even alert you when the ISS is expected to pass over your location on Earth.
My favorite website for keeping up with the travels of the ISS is www.heavensabove.com. With Heavens-Above all you have to do is configure it for your location with their massive database. Among many of its features, it'll provide a schedule for ISS flyovers and even a sky map to track it. You can also find out when other bright satellites will be passing over. My favorite free app for tracking the ISS is ISS Tracker. Allow that app to know your location, and you're good to go.
Depending on where it's crossing your sky, the ISS can take up to around five minutes to pass. It resembles a super bright star. Depending on when you're watching it, in the early morning or early evening, it can suddenly disappear in the sky as it enters the Earth's shadow, or it can pop into view coming out of the shadow in the early morning.
As much fun as it can be to observe satellites in the night sky, I'm afraid that in the future the skies may become too crowded. I'm worried that it's already beginning to happen. In particular I'm referring to Starlink satellites launched by the Space Exploration Technologies Corporation, otherwise known as SpaceX, a private space transportation enterprise founded in 2002 by South African native Elon Musk.
Starlink satellites can provide much more available access to the internet throughout the world, even in remote areas. Already, there are hundreds and hundreds of Starlinks in orbit, and it's very easy to see them, sometimes in groups or lines, especially after they are first launched. As it is with the International Space Station, you can keep up with all of them on the Heavens-Above website, as well as other sites and apps.
The big fear is that the natural beauty of the night sky could be ruined with too many satellites. Earth-based astronomical observations, both done by professionals and by amateur astronomers, are going to be interfered with significantly. I believe, and so do many others, that there must be some international regulations to keep this from happening. I can tell you as an astrophotographer that it's getting tougher and tougher to get time-exposure images that aren't marred by satellite streaks.
Watching satellites is a lot of fun but let's not get the heavens too congested!
Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of 'Stars: a Month by Month Tour of the Constellations,' published by Adventure Publications and available at bookstores and adventurepublications.net. Mike is available for private star parties. You can contact him at [e-mail].
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