Spectacular Perseid Meteor Shower

The Perseids are back. This spectacular meteor shower returns every August and will be most active on the nights of August 11-12 and 12-13.

– They can be seen a week before and a week after, but are best at their peak, says Peter Linde, chairman of the Swedish Astronomical Society.

The Perseids, named because they appear to come from the constellation Perseus, have been observed for a very long time, about 2,000 years. The swarm consists of dust and small stones released from the comet Swift-Tuttle, which passes through the inner solar system between the sun and Jupiter every 133 years, last in 1992.

Shower of Shooting Stars

The shower occurs when Earth passes directly through the particles' path. The comet debris looks like a shower of shooting stars as they plunge into Earth's atmosphere. The amount varies slightly from year to year, depending on how much debris the comet has left behind.

– The dust particles are very small, less than half a centimeter, says Peter Linde.

Burning Up

The particles travel at a speed of 60 kilometers per second when they hit the atmosphere. The friction during deceleration is so intense that they heat up to a temperature of over 1,000 degrees. It is when the particles start to burn that we see them – resembling falling stars. When the shower peaks, it is possible to see up to 60 such meteors per hour.

Interestingly, they are mainly visible from the Northern Hemisphere, which is related to Swift-Tuttle's orbit.

– However, this year they will not be as visible as in some other years. There will be a full moon just before, which means there is a bit more light in the sky than usual, says Peter Linde.