The comet was discovered on March 27 and got its name from the space telescope that first saw it - Neowise, which belongs to Nasa. The space telescope is used to collect data on, among other things, comets and asteroids passing near the Earth.
- This comet has a turnaround time of 6,800 years. So this comet is not entirely new, says Johan Warell.
A snapshot from the ISS International Space Station on July 5 where the comet Neowise is visible over the curvature of the earth. Photo: NASA, ISS Expedition 63
He is chairman of the Swedish Amateur Astronomical Society and representative of ESO's European Southern Observatory, outward-looking operations in Sweden. Johan Warell says that together with everyone who is interested in what is visible in the sky, he waited to experience something like Neowise.
- So far, you have not seen anything that is particularly unique to this particular comet, but it is interesting because it is unusually bright. The last we could see a comet that was so bright from our latitudes was Hale-Bopp 1997, so it's the finest comet since then, says Johan Warell.
Comet Neowise sighted from the Lindby Observatory in southern Skåne by Johan Warell. Photo: Johan WarellDirty snowballs with double tails
He tells us that comets are usually described as dirty snowballs. They consist mainly of ice of various frozen substances and mostly ice of water. When the comet comes close to the sun, the ice begins to melt and turns directly into gaseous form. When the gas leaves the comet, it also carries dust that has been frozen in the ice.
- The gas flows out of the comet's surface through geysers. Both the gas and the substance become visible to us, says Johan Warell.
Comet Neowise sighted from the Lindby Observatory in southern Skåne by Johan Warell. Photo: Johan Warell
He tells us that a comet has two tails. The yellow becomes visible to reflect the sunlight on the substance leaving the comet. The blue comet tail produces its own light.
- The gas and water vapor are bombarded with sunbeams and then many charged molecules are formed that emit their own light and thus form their own tail. It's called the ion tail, or the plasma tail.
Johan Warell thinks you should take this unique opportunity and look at Neowise which should be visible for the rest of the month.
- It's great that we got such a nice comet. It may take 20 years before we get something like that, it's a generational event, ”he says.