What are Shooting Stars and Where do They Come From17th Nov 2022
People have always romanticised natural phenomena and assigned magical meanings to them. Shooting stars, which are not stars at all, are a bright example. Legends about the magical nature of the phenomenon exist in a variety of cultures, but at the current level of scientific development, one should clearly understand that the falling stars are just space objects that abide by the rules of physics and burn while moving through the atmosphere. But, more precisely, what are shooting stars? What do they consist of? What colour they are? And how can one see them in the UK? Find answers to these questions below.
Shooting stars: what are they?
As large, heavy and distant as stars are, they cannot be pulled by Earth’s gravity. A star is a hot gas ball of colossal size and mass that far exceeds our planet’s. At the same time, each star has its trajectory, supported by gravity and internal pressure forces, so it cannot change its way abruptly. Even if a star were somehow made to move towards Earth by external forces, it would take a lot of time for one to reach Earth.
The closest star to Earth (other than the Sun), Proxima Centauri, is about 4.24 light-years away. With one light-year equaling 6 trillion miles (9 trillion kilometres), the risk of a star falling on Earth is down to zero. Thus, what seems to be the falling stars are actually meteors, otherwise known as shooting stars. So what exactly are shooting stars?
Those are traces of the small fragments of meteorites and asteroids, which, burning in the Earth’s atmosphere, cause the lighting effects one can observe, sometimes even without specific equipment.
Other than the standalone shooting stars, one could also see dozens of them moving towards Earth simultaneously. This happens when a group of space objects enters Earth’s atmosphere instead of a single object. Such a star shower occurs when the Earth’s orbit intersects with the trails of debris left after the broken-up comet or asteroid has passed.So
As a rule, we are talking about hard rock minerals that are part of comets. When a comet follows its path in the solar system, minor particles are inevitably separated from it and assembled into huge “tails” of different sizes and lengths. After Earth crosses their way and they get into the Earth’s atmosphere, they evaporate due to high temperatures caused by friction with the air. As a result, streaks of light are formed, which we see and perceive as falling stars.
What colour are shooting stars?
Meteors themselves are not sources of light. Their glow is caused by ionisation. The glow’s strength, brightness, duration and spectrum depend on the particle’s size, speed and composition. They can give off reddish, greenish, blue, and other colours. It all depends on the composition and its reaction with atmospheric oxygen. Also, the evaporating components will give a colour corresponding to their emission spectrum, which depends on the temperature the bodies reach during their fall. Some burn out quickly, while others are visible for a few seconds. The larger the particle, the brighter trail of ionised air it leaves. Sometimes this light could be so bright that one can see it through the clouds.
To see a shooting star in the UK, you need to get away from urban centers, as the surrounding light sources make it difficult to observe the sky. This is best done in national parks (for example, Northumberland), among the picturesque Welsh Mountains, surrounded by Brecon lighthouses or the South Downs International Dark Sky Reserve. With a new moon and a clear sky, you will be greatly impressed.
Meteor showers get their names to highlight their relation to the constellations from where they come. What are shooting stars called, specifically? Two examples are the Orionids and Perseids. And with them, you can easily conclude that they come from the Orion and Perseus constellations, respectively.
Some meteor showers happen regularly. For instance, one can observe the famous Perseids with more than 60 meteors per minute in August each year when Earth passes through Swift-Tuttle’s orbit. Orionid shower occurs every October, promising the patient observers a frequency of 50 to 70 shooting stars per hour. The Quadrantids happen annually at the beginning of January, allowing observers to enjoy a short-lasting show.
By the end of 2022, one can still observe meteor showers in the UK sky, including the brightest one. Find the list of the shooting stars you might still witness this year below:
- Leonids ─ one of the most abundant, fast and spectacular meteor showers. What are these shooting stars? These are the remnants of the comet Tempel-Tuttle burning up in the atmosphere. In 2022, their visibility will peak between midnight and dawn on November 17-18.
- Geminids — one of the last major meteor showers of the year, peaking around December 14-15. These are very bright, moderately fast and unusual meteors because they are multi-coloured. What colour are these shooting stars? Mostly white, but one can also see yellow-green, red, and even blue ones. Such a rainbow is partly due to sodium and calcium traces. The same effect is used to add colour to fireworks.
- Ursids ─ usually a rare shower, with about five meteors per hour. In 2022, its observation peak falls on December 22–23. The shower visually “falls” from Beta Ursa Minor (Kochab) in the constellation Ursa Minor. The debris emerges from the stream left after the Comet Tuttle.
You can also find a detailed list of all shooting stars in the UK via this link.