There are many luminous objects in the night sky. But how do you know if you’ve noticed a star, planet, satellite, or something else entirely?
MUNICH – When temperatures are mild in spring and summer, people like to spend more time outdoors gazing at the starry sky at night. There are many things that shine brightly and are especially noticeable if you don’t look up at the sky much. Whether it’s a seemingly steady bright light, a “star” moving rapidly across the sky, or some other phenomenon that catches your eye, most celestial observations can be resolved with relative ease.
The most important information for knowing what you saw in the sky is the cardinal direction and the time of observation. If you don’t have a compass handy, you can use the sun to roughly determine which direction you’re facing. For example, use the well-known phrase “The sun rises in the east and rises high in the south. In the west it will be set, in the north it will never be seen.” Just by the key point alone, you can explain some things more easily. For example, in the spring of 2023, Venus will be very visible in the west in the evening. So if you notice a very bright “star” in the west in the evening, it’s most likely the “evening star” Venus.
The “bright light” in the sky does not move: a star or a planet
If you see a “bright light” in the sky that does not move for a long time, it is most likely a star or planet. To distinguish them, take a closer look: The stars shine, but the planets do not. The twinkling of stars is caused by turbulence in the Earth’s atmosphere, which light must pass through in order to reach the human eye. Although the light from the planets also penetrates the Earth’s atmosphere, planetary flashes are usually not noticeable because the planets are noticeably brighter.
If you’re still not sure if you saw a star or a planet, there are other options. For example, use a digital star map like the free Stellarium app (also available for smartphones) to see what you saw in the sky. After installing the app, you can point your smartphone at the celestial body to see what it is. To distinguish a star from a planet, it also helps to observe the celestial body for several nights. Planets move across the starry sky over time, moving from one constellation to another. For this reason they were called “wandering stars”.
A “bright light” is moving quickly across the night sky: a satellite or an airplane
If you see a “bright light” moving rapidly across the night sky, there are also a number of possibilities as to what you may have noticed. For example, it could be a satellite or an aircraft. The distinction is relatively simple: planes Flash, satellite no. If the object is flashing in the sky or has green or red lights, it is an airplane. You can recognize satellites because they do not blink, but rather move across the sky as more or less bright points of light and then suddenly disappear again.
With some experience, you will be able to distinguish between different types of satellites. For example, SpaceX’s Starlink satellites usually appear in larger clusters — one satellite is followed by several others. The International Space Station ISS, which can sometimes be seen in the night sky, remains alone and shines brighter than the Starlink satellites. You can follow the paths of different satellites using apps such as “Stellarium” or “Heavens Above”. In addition to the direction of your observation, you also need the exact time you observed it.
Unusual sights: Starlink satellites confuse the sky
Besides these everyday sky sightings, there are also more unusual ones that have seen people calling UFO call centers. The UFO Reporting Office of the Central Research Network of Unusual Celestial Phenomena (CENAP) explains these phenomena, with balloons or drones often behind the observations. However, Starlink satellites often confuse people looking up at the sky.
And this is not surprising: they cannot be considered simply as individual satellites flying one after another at a distance. Soon after launch, they are so close together that they create an almost eerie trail of light across the sky. Many observers refer to the Starlink satellites after their launch as “strings of lights” in the sky.
Rocket launches can also look strange in the sky
Different stages of rocket launches can also look strange in the sky. For example, the helix can occur when the rocket stage emits residual fuel. You can also sometimes see rocket parts burning or a rocket stage breaking off in the sky. On the other hand, shooting stars, meteorites and fireballs are of natural origin. Here, a fairly large rock from space enters Earth’s atmosphere and burns up. Information on other fireball sightings can be found in a special database, where you can also report your own sightings.
Machine assistance was used in this editorial article. The article was carefully screened by editor Tanya Banner before it was published.