2021’s Once In A Lifetime Comet - Leonard
Comet Leonard is one of those once-in-a-lifetime sky events provided by nature. That is, it takes tens of thousands of years for this comet to complete an orbit around the sun. This celestial visitor has an incredible feature - an ultrafast comet. It is moving at 158,084 miles per hour (254,412 kilometers per hour or 70.67 kilometers per second) relative to Earth.
But, despite its incredible speed through our solar system's vast space, don't expect to see this comet swoosh across the sky. Comets, like planets, move in front of the starry background. However, because of the large distances involved, they appear to move slowly to our eyes making it possible for enthusiasts to take a picture of it.
Astrophotographer Chris Schur captured this stunning photo of Comet Leonard on Dec. 4, 2021 from Payson, Arizona using a 10-inch Newtonian telescope and 60-minute camera exposure. (Image credit: Courtesy of Chris Schur)
Comet Leonard as seen by skywatcher Christian Gloor. (Image credit: Christian Gloor/CC BY 2.0)
According to Leonard, its origins are most likely from the Oort Cloud, which is a vast reservoir of millions, if not billions, of comets. The Oort Cloud is a long way away from the sun. It is at least 5,000 astronomical units (the sun-Earth distance) and may extend to 100,000 astronomical units. This comet is a long-period comet that most likely originated in the inner Oort Cloud, 3,700 astronomical units away. For the past 40,000 years, the comet has been inbound on this leg. However, if we go back far enough, we can see that it has been on an 80,000-year orbit. It last entered the inner solar system 80,000 years ago. Talk about some really old comet!
Although the comet was spectacular it was short-lived (from the time it was discovered). Leonard discovered the comet one year before perihelion. The perihelion, or closest approach to the Sun in the comet's orbit, is only 0.6 AU. This is between Mercury and Venus's orbits. Its aphelion, or closest approach to the Sun, is 35 AU (roughly the distance of Pluto).
So what happens when a comet is at perihelion? Comets reach their brightest point near perihelion, releasing massive amounts of gas and dust. Outbursts and other unpredictable events are also possible around perihelion, so it is critical to collect as many observations as possible during this time.
Did I also mention that it was short-lived? According to the report, an icy wanderer known as Comet Leonard (C/2021 A1) disintegrated during its perihelion, or closest approach to the sun. Perihelion was predicted to occur on January 3, about a year after the comet was discovered.
"Comets, particularly those with extraordinary apparitions, somehow insist that we pause to admire their magnificence and mystery," Gregory Leonard told EarthSky. "I also appreciate that comets are reminders of the transient nature of … well nature, and all things. And of course, comets are full of surprises, reminding us that we humans are not in control."
We are merely here to enjoy the wonder of nature. So it is better to take a step back and enjoy what nature has to offer because we never know when the next spectacle will happen.
