All over the globe there are people with their eyes on the sky. From our astronomers and guests at the Aurora Borealis Observatory eagerly looking for the northern lights, to astronomers using the largest telescopes in the world in even more remote locations. These astronomers monitor objects of interest, collect huge amounts of data for research and some are even on the lookout for new discoveries.
In December, a remotely operated telescope in Hawaii spotted Comet C/2019 Y4 (ATLAS). The ATLAS Project consists of two 0.5m telescopes around 160 km apart from each other. The ATLAS telescopes scan the sky several times every single night, looking for potentially hazardous asteroids and other objects of interest. It’s basically an early warning system for potentially hazardous objects that could strike anywhere on the Earth and cause damage, just like the famous Chelyabinsk meteor that exploded over Russia on 15thFebruary 2013 and caused $30 million worth of damage.
This time these telescopes discovered a comet, a cosmic snowball made up of rock, dust and frozen gasses that is orbiting around the Sun, just like us. Most comets live out beyond dwarf planet Pluto, in an area of space called the Oort Cloud, but when a comet’s orbit brings it into the inner Solar System and closer to the Sun it heats up, which causes the ices inside the comet to turn into gases, a process called sublimation. This creates a coma of gas around the comet and a tail which makes it much more visible.
There are many notable comets throughout history, the most famous is probably Comet Halley which has been recorded as being observed as far back as 240BC, over 2000 years ago! Comet Halley takes just over 75 years to orbit the Sun which means it’s visible from the Earth every 75 – 76 years, this was first predicted by English astronomer Edmond Halley, after whom the comet is now named after. In contrast to Comet Halley, C/2019 Y4 (ATLAS) takes around 6000 years to orbit the Sun so this will be the only opportunity every human on the Earth will get to see it.
The reason C/2019 Y4 (ATLAS) is exciting astronomers is because it’s brightness is increasing so rapidly that astronomers think that if continues to do this it could be as bright as the planet Venus in the sky, to put that into perspective Venus is the third brightest object after the Sun and the Moon.
Currently C/2019 Y4 (ATLAS) is sitting in the constellation Ursa Major which is in the Northern Hemisphere, it’s not bright enough to see with the naked eye but it can be picked up in small telescopes like the image below taken by Dan Monk from Kielder Observatory. As we move through the spring and into May (when the comet’s brightness is predicted to increase) it will slowly move over into the constellation of Perseus which will take it into the evening twilight and make it more difficult to spot. The best time to look for it will probably come in late April when it’s still in the evening sky.
Here at the Aurora Borealis Observatory in Senja, from May onwards and throughout the summer the Sun will no longer set, we will experience the famous Midnight Sun. This will make it impossible to spot the comet but at more southern locations on the Earth, down to Southern Europe there is still a chance of seeing it.
Astronomers are careful when getting excited about comets, the Canadian comet hunter, David Levy famously said, “Comets are like cats: they have tails, and they do precisely what they want.” C/2019 Y4 (ATLAS) could become a comet remembered for generations to come, or it could fizzle out and disappear as quickly as it appeared, only time will tell. Our advice is to keep an eye on the Aurora Borealis Observatory news section for up to date information on astronomy and many other exciting topics.