Till now 2018 had been a great year for the stargazers as people had already witnessed the two total lunar eclipses, two partial solar eclipses, Perseids meteor shower and many more.
Now this time sky gazers have yet another visual feast in line for them. The remaining of the year will showcase two comets, Comet 21P/Giacobini-Zinner and Comet 47P/Wirtanen, in the skies.
About Comet 21P/Giacobini-Zinner
Comet Giacobini–Zinner commonly known amongst as comet 21P is a periodic comet in the Solar System with an orbital period of around 6.6 years.
It was discovered by Michel Giacobini (from Nice, France), who observed the comet in the constellation of Aquarius on December 20, 1900. It was recovered two passages later by Ernst Zinner (from Bamberg, Germany) while observing some variable stars on October 23, 1913.
The comet nucleus is estimated to be 2.0 kilometers in diameter.
Closest approach to Earth
Comet 21P is currently approaching the Earth and sun at incredible speeds (about 14 miles/second, or 23 km/s). Its closest approach to both the Earth and the sun will take place on the same day – September 10, 2018 – when this comet will sweep past Earth at a completely safe distance of 36 million miles (58 million km) from our planet. It had already been sighted from some darker locations as shown in the picture.
This image was clicked on 22nd August 2018
This would be the closest approach of the comet 21P in 72 years.
How to observe
In late August, the comet glows at magnitude 7.5 and is expected to peak at around 7 next month, small telescope). On its closest approach predictions peak at magnitude 6, so only just within the naked eye threshold. Through the summer months, comet 21p passes within close visual proximity to quite few deep sky objects during its journey through Cygnus, Camelopardalis, Auriga and Monoceros.
On its closest approach during 10-11 September it will also be in vicinity of M37, the richest and brightest open cluster in the Auriga constellation, in the sky.
Parent of Draconids
21P/Giacobini-Zinner is the parent comet of the annual Draconids meteor shower, which peaks on October 9th, it’s normally a weak shower that generates only a handful of meteors per hour.
The next approach of the comet 21P will be around the end of 2024 or beginning of 2025. So if you don’t want to wait till then to feast your eyes, now is the time to get out with your binoculars or small telescopes and lookup! But if you do happen to miss the comet, there’s another one visiting our neighbourhod in the next few months.
About 46P/ Wirtanen
The comet Wirtanen commonly known as Comet 46P was discovered on January 17, 1948 by American Astronomer Carl A. Wirtanen. It is a short period comet with an orbital period of 5.4 years.
Closest approach to Earth
Comet 46P/Wirtanen had begun its apparition (magnitude 10.5) along the Cetus–Fornax constellations border in the late September morning sky. About mid-November, 46P will be heading straight north with ever-increasing speed, rocketing in brightness and altitude until it towers in Taurus in all of its 4th-magnitude glory two weeks before Christmas. Its closest approach to Earth will be on 16th December 2018.
Comet 46P’s exceptionally close approach to Earth of 11.5 million km on December 16th could mean several weeks of naked-eye visibility from dark skies. Comet Wirtanen is intrinsically bright, comes closest to our planet just four days after perihelion, and remains visible all night, making this an exceptional apparition.
How to observe
The comet will be visible through naked eyes only from dark skies, else a binocular or small telescope can be used.
The comet is approaching us during the end of this year in December, if you miss even this one, you will have to wait for 5.4 years more, that is until mid-2024.
So, get ready with your gears and let’s welcome the celestial visitor in our skies and don’t forget that it can be a good opportunity for the Astrophotographers to capture their visits…….