Dusseldorf. When the first chariots drove and Stonehenge was built again in England, the Comet C / 2020 F3 came close to Earth. After 4500 years it comes again – and shines brightly in the night sky in July.
Comets are not the most frequent visitors to Earth. And they are not always easy to see. But when they draw attention to themselves, it’s spectacular. The best-known representative is Halley’s comet, which comes close to Earth approximately every 75 years and is not expected until 2061 next time. But on March 27, the Neowise space telescope discovered a new visitor from the depths of our solar system: the Comet C / 2020 F3. In the meantime he is nicknamed “Neowise” after his “discoverer”, who has been exploring space in the infrared range since 2009. The space telescope was actually put on hold in 2011 because the coolant had run out. But it was reactivated in 2013 and since then has been looking for celestial bodies that come close to the earth and can become a potential danger. And the comet got into its electronic network.
However, it was initially very dim and more than 250 million kilometers away. But the closer he got to the sun, the brighter it got. The reason lies in the comet itself. They are relics from the formation of the solar system, which consist of ice, dust and rock. As these lumps of ice come closer to the sun, they heat up. Some of the ice turns into gas and the comet pulls it like a tail. If the constant stream of particles from the sun – the solar wind – hits the gas, it stimulates it to glow. It is the same physical process that creates Northern Lights on Earth. Only in the vastness of space and in the tail of the comets.
And they either come from the so-called Kuiper belt, which is located beyond Neptune and in which Pluto also moves. Just like Halley’s comet. Or they come from the Oort cloud: In theory, remnants should be found there more than a light year away. From the time 4.5 billion years ago when our solar system was created. Due to the gravity of the big planets like Jupiter, they were thrown to the extreme limit of our system. However, disturbances such as collisions with each other sometimes guide them along paths that make them revolve around the sun for thousands of years. Like C / 2020 F3.
On July 3, he came very close to the sun. At 43 million kilometers, it was even closer to it than Mercury. He survived that. Some comets lose too much mass or are torn apart by the sun’s gravity. Now it is moving away again, but the C / 2020 F3 is still flying past Earth: on July 23, it even comes close to about 100 million kilometers. But from July 10th he will be seen all night. You can find it if you orientate yourself towards the northwest on the constellation “Big Dipper” – and extend the front stars to the right. The comet is then discovered under the bright star Capella.
And it is a unique opportunity for us to see him. According to the British Royal Astronomy Society, the close encounter with the sun and soon with earth will change the comet’s orbit. It will not return in 4500 years, but only in around 6800 years.
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