A Visitor That Took 50 Thousand Years To Return

    If you have ever looked up in the sky and wonder about the marvel of our universe, you form part of the thousands of year tradition that led human curiosity to explore the vast cosmos. In our exploration we have encountered planets, stars, galaxies, black holes, and comets. The latter being one of the most mesmerizing and rare events one could ever see.

    A comet is an icy, small solar system body that when passing close to the Sun warms and begin to release gases in a process called outgassing. Their icy center called the nucleus surrounded by a cloud of gas called the coma which is like a visible atmosphere. The ice is Regularly made of water (H₂O), carbon dioxide (CO₂), ammonia (NH₃) and/or methane (CH₄). They are a testament of the solar system early stages.

    Comets can develop two tails as they travel closer to the sun. the ion or gas tail, and the dust tail. The gas tail is created by the solar winds and the ice, it always points back from the sun. The dust tail is not affected by the magnetic field but is vaporized by the sun’s heat. Stargazers and astronomers enjoy the looking at the gas tails for its brightness and beauty while the dust tail to determine their trajectory.

Picture courtesy of NASA.

    Comets travel in Highly elliptical orbit starting out around Neptune or father away in our solar system in the Oort cloud. Due to their travel trajectory, they can end up leaving our solar system so they can become a one-time event.

    Among some of the most famous names we got the Halley’s comet which becomes visible to Earth every 75 years; Shoemaker-levy9 which was discovered in 1992 when it split and crashed into Jupiter, and the Hale-Bopp which was one of the most observed and brightest comets of the 20^th century. Some comets take hundreds and even thousands of year to complete their orbital period which is why when one is approaching people search the skies for the opportunity to see them. This year we got the opportunity to see a once in a lifetime comet that hasn’t been previously seen.

    Officially called C/2022 E3 (ZTF), this comet was discovered in March 2022, and it was determined that it would make it closest approach to Earth on February 1-2, 2023. What makes this comet so special is that the last time the comet approached Earth was 50 thousand years ago. A period where Neanderthal roamed the Earth. Unlike now the sky was much darker because they did not count with the technological advancement of electricity, so it is possible that Neanderthals saw the comet, but we have no records of this as it hasn’t been seen ever again since. The comet was visible to the naked eye during Feb 1-2 in certain regions of the planets but as it makes its exit you need a telescope to search for it.

    Unlike other comets this one is made of Diatomic carbon and cyanogen which makes it look green and it could be spotted near mars by Feb 10^th. If you miss it do not worry as advancement of technology has allow for recording of the comet to be made. Here I share one of the pictures taken of C/2022 E3 (ZTF).

Copyright Dan Bartlett.

    Comets leave behind black organic compounds when heated up that are studied as they may contain essential chemicals for life. There is the theory that comets may be the key to how life came to be on Earth. As they contain water and other resources essentials for life. In 2005, the Deep Impact Probe was launched to study the interior composition of comet Tempel 1. We await excitedly its return to see what we can learn from it.

    Comets are among some of the earlier remnants of the early universe. We can learn some much from them and they are also a beautiful sight to see. Being able to see one live is something you can tell your grandkids about.