Meteor in the atmosphere: a grain of sand glows
About this app
A grain from Halley hits the air at 66 km/s and glows at about 115 to 90 km, far above clouds and aeroplanes. Magnifier on the glowing grain, speed comparison, the radiant near Orion explained with rails, and the best time to watch on 22 Oct 2026.
With explain mode: an AI tutor walks you through the app, points out what matters in the scene and answers your questions.
The science
A shooting star is not a star. It is a dust grain, usually smaller than a grain of sand, that hits the atmosphere at high speed. For the Orionids this is about 66 kilometres per second, more than 200 times as fast as an airliner. In front of the grain the air is squeezed so hard that it becomes very hot. The grain evaporates, and the air along the trail glows, at about 115 to 90 kilometres. Nothing reaches the ground. All grains of a shower fly in parallel; from below their trails seem to come from one point, the radiant.
What you see
The side view shows the atmosphere up to 140 kilometres with clouds and an aeroplane. A grain flies in slow motion and lights up in a band; a magnifier shows the air glowing in front of the grain and the grain shrinking. Speed bars compare aeroplane, Earth and meteoroid. The sky shows the view to the south-east on 22 October 2026 at 4:30 am with Orion; extended trails meet at the radiant, and railway tracks show the same effect. A chart shows the radiant and the Moon through the night.
Things to try
Change the speed: slow grains glow lower down, fast ones higher up. Compare in the magnifier how small the grain is and how large the glowing trail. Let many meteors appear and switch on the backward extension, then switch the rails between “from above” and “from the track”. Finally move the time in the chart to find the best time to watch: after moonset at about 3:15 am until dawn at about 6 am (central Europe).
Frequently asked questions
- Why does a shooting star glow?
- A dust grain hits the atmosphere at many kilometres per second. In front of it the air is strongly compressed and heats up, the grain evaporates, and atoms along the trail emit light. This usually happens 80 to 120 kilometres up and lasts less than a second.
- What is the radiant of a meteor shower?
- The radiant is the point in the sky from which all meteors of a shower seem to come. The grains fly in parallel; seen from Earth their trails converge in one point because of perspective, like railway tracks in the distance. For the Orionids it lies in Orion near Betelgeuse.
- When are the Orionids best seen in 2026?
- The peak is on the night of 21 to 22 October 2026; the nights before and after are worth it too. The radiant rises at about 10:20 pm (central Europe). The bright waxing Moon sets at about 3:15 am, and from then until dawn at about 6 am the sky is darkest. Under a very dark sky 10 to 15 meteors per hour are then possible.
- What does the "meteor in the atmosphere" app show?
- The flight of a grain through the atmosphere in slow motion with a magnifier and a speed comparison, the sky with Orion and the radiant, and a chart for the best time to watch on the night of 21 to 22 October 2026.
Subject: Astronomy
More from Astronomy
- Armillary sphere — the sky as rings (3D)
- The Sun today
- Exoplanet Galaxy (3D)
- Expansion of the universe (3D)
- Gravitational waves (3D)
- Life of stars (3D)
- Meteor shower: Halley's dust trail and the Earth
- Moon phases and eclipses
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