Comet Atlas Broken – Enter Comet Swan
Our astronomers at the Aurora Borealis Observatory were getting excited at the possibility of seeing a bright comet in our sky. In December 2019 astronomers in Hawaii discovered a new comet entering our inner solar system. Comet Atlas was confirmed and the excitement around it started to build, this could be the brightest comet we have seen for decades.
A comet is 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 gases inside the comet to turn into ice, a process called sublimation. This creates a coma of gas around the comet and a tail which makes it much more visible.
As Comet Atlas started to brighten at a surprising rate the excitement and anticipation for a remarkable comet started to grow until mid-April when something changed. The brightness of Comet Atlas started to decrease; this was a bad sign. On April 20th the Hubble Space Telescope, which is celebrating its 30th year in space, photographed Comet Atlas and confirmed that it had broken apart. The image of what remains of Comet Atlas is quite spectacular and even though the comet is no more, the event of a comet breaking up and imaging it is still incredibly useful for scientists and allows them to better understand them and how they break apart. “This is really exciting — both because such events are super cool to watch and because they do not happen very often,” Quanzhi Ye, of the University of Maryland and the leader of a second Hubble observing team, said in the same statement. “Most comets that fragment are too dim to see. Events at such scale only happen once or twice a decade,” she added.
Now that Comet Atlas is no more, a new and equally as exciting comet is taking the headlines, Comet Swan. The comet was discovered in images taken by the SWAN camera on March 25, 2020, aboard the Solar Heliospheric Observer (SOHO) spacecraft. This spacecraft was launched in December 1995 and its main mission is to monitor the outer layer of the Sun and the solar wind. At the Aurora Borealis Observatory, we use the solar data from this spacecraft to help predict the appearance of the aurora borealis for guests on their northern lights holidays. During it’s time in space it has discovered over 3000 comets! Because the orbits of comets have them tumbling in towards the Sun they appear within the view of the spacecraft as they get closer and brighter. It’s a wonderful consequence of this Sun observing craft and has allowed astronomers to study comets in more detail.
Comet Swan is currently visible in the southern hemisphere in the constellation of Cetus the Sea Monster and its brightness has just reached a point where it is visible to the naked eye in dark skies. Unfortunately, the Moon is heading into its full phase which will make it more difficult to spot. It will pass through the celestial equator (the plane of the equator) on 7 May headed northward and be near the 2nd magnitude star Algol on 20 May. In the Northern hemisphere it might be best seen at the end of May when it is near the star Capella in the constellation of Auriga.
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) will be remembered alongside many other comets that have promised so much and unfortunately not reached their potential. It is thought Comet Swan could take the same path as the two are similar in size. Our advice is to keep an eye on our news section for up to date information on astronomy and many other exciting topics.
Credit: David Levy