Two satellites that were designed to monitor the sun captured footage of Comet Leonard speeding past Earth. It was the brightest green comet in over 70,000 years. 

At nearly 160,000 miles per an hour, the comet has approached Earth and the Sun since January, which was its year of discovery. 

It measures about half a kilometer in diameter and was captured using the NASA Solar Terrestrial Relations Observatory – Aspacecraft (STEREOA) and European Space Agency (ESA – Solar Orbiter observatory.

Since November, STEREO A has been following the green comet. NASA’s team was able to create a brief animation using dozens of images.

NASA released a “difference picture” to show the brightness changes caused by comet emissions.

ESA’s spacecraft captured video of the comet moving across the field between December 17th and 19th, 2021. This was a joint effort with NASA.

A pair of satellite designed to observe the sun have captured video of the bright green Comet Leonard, as it speeds past the Earth for the first time in 70,000 years

The bright green Comet Leonard speeds past Earth in the video captured by two satellites that were designed to see the sun.

The ball of ice and dust is about half a mile wide, and was captured by the NASA Solar Terrestrial Relations Observatory Aspacecraft (STEREO-A) (right), and the European Space Agency (ESA) Solar Orbiter observatory (left)

This ball of ice-and-dust is approximately half a mile in diameter and was captured by NASA’s Solar Terrestrial Relations Observatory (STEREO) (right) and European Space Agency (ESA), Solar Orbiter observatory.


Comet Leonard, which is cataloged under C/2021 AI (astronomical instrument), was named for the first person to discover it.

Gregory J Leonard was the one who spotted it using Mount Lemmon Observatory in January 2021.

It was one year ago that it reached perihelion, the closest point to the sun.

The sun’s last appearance in the solar system was 70,000 years ago. It is currently orbiting the sun for a period of 70,000 years.

It will orbit this star on its final orbit, as it is currently traveling in a hyperbolic path. This means it will exit the solar system following its near approach to its host star. 

Comet Leonard will come within millennia of the Sun on January 3, 2022. Before that, both satellites used to observe the sun were directed in its direction. 

NASA created an animated “difference picture” with a grey background that highlights the comet’s tail and shines in space.

The current frame was subtracted from the preceding frame in order to emphasize the differences. 

Difference images are useful for seeing subtle changes in Leonard’s ion tail, which is the trail of ionised gases streaming from the comet’s body.

You can see it getting longer and brighter towards the end. 

Solar Orbiter Heliospheric Camera (SoloHI), which was captured the video, showed it moving diagonally in its field, while Venus, Mercury, and the Milky Way are also clearly visible.

Solar Orbiter is seen moving towards a sidelong view. This allows for more detail of the comet as it traverses space. 

SoloHI was able to continue watching the comet up until today, and more footage could be made.

Gregory Leonard was the one who discovered Comet Leonard in January 2021. He took images from Mt. Lemmon Observatory Arizona 

The Sun’s nearest pass will be on January 3rd 2022. It will come within 56,000,000 miles of our star. That is roughly half the distance from Earth to the Sun. 

If it doesn’t disintegrate on its way to the Sun, then Comet Leonard’s trajectory will fling it into interstellar space, never to return. 

Scientists believe it could be already splitting within a year of its discovery, or that it will soon begin to separate. 

A comet is heated up when its orbit closes to the Sun. It spews gases and dust into a huge glowing head that is larger than any other planets. 

It will make its closest approach to the Sun in millennia on January 3, 2022, and ahead of that event both solar observing satellites were pointed in its direction

On January 3, 2022 it will come within millennia of the Sun. Both solar-observing satellites pointed at its direction before that time. 

Comets – also called ‘cosmic snowballs’ or ‘icy dirtballs’ – are conglomerations of frozen gas, dust and ice left over from the formation of the solar system. 

The orbit they take around the Sun is highly elliptical. This means that their paths are not perfect circular. They can also spend thousands or hundreds of years deep in the Solar System’s darkest parts before coming back to the Sun for their “perihelion”. 

Comet Leonard, however, has a hyperbolic or orbit which means it will pass the Sun and be ejected into the Solar System. Earthlings won’t see it again.  

Comet Leonard was discovered in January 2021 by Gregory Leonard, who spotted it in images taken from the Mt. Lemmon Observatory in Arizona

Gregory Leonard, who saw it from images taken at Mt. Lemmon Observatory, Arizona 

When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets

A comet is heated up when its orbit closes to the Sun. It spews gases and dust into a huge glowing head that’s larger than any other planet. 

Comet Leonard probably spent around 35,000 year coming inbound approximately from 323 billion mile (520 billion km). It may also have visited the inner solar systems about 70,000 years before.  

Comet Leonard approaches Earth closest on Sunday, 12/12/12 before its perihelion in January 3.  

Because its interior of icy rocks heats up closer to the Sun it emits a blue dust first, followed by yellow, white, and then finally green.

If it changes to a teal-colored colour it indicates it is hot, has lots of diatomic carbon, and may be at the highest risk for breaking up.    


This article is about asteroid This is large piece of rock leftover from early solar system collisions. They are found between Mars and Jupiter within the Main Belt.

Comet A rock that is covered with ice, methane or other compounds. They orbit much farther out than the sun.

Meteor This is what astronomers refer to as a flashing light in the atmosphere that occurs when debris starts burning up.

It is sometimes called a debris. meteoroid. Many of them are small enough to be vapourized in the atmosphere.

A meteoroid that makes it to Earth is known as a “at-home” Meteorite.

Asteroids and comets are the usual sources of meteoroids, meteoroids, and meteorites.