Skip to main content

A landslide may have caused this brilliant comet outburst captured by Rosetta

In what seems like a great stroke of luck, the Rosetta probe has captured data and images of a brilliant comet outburst, which astronomers think may be the aftermath of a landslide.

On February 19, as Rosetta trailed Comet 67P/Churyumov–Gerasimenko from about 22 miles, nine of the spacecraft’s instruments were pointed at the comet for coordinated monitoring. Suddenly, a cloud of gas and dust rose from the comet in an outburst. With its instruments in focus for the next few hours, Rosetta captured a series of images and data, transmitting them back to Earth within a couple days.

“Over the last year, Rosetta has shown that although activity can be prolonged, when it comes to outbursts, the timing is highly unpredictable, so catching an event like this was pure luck,” Matt Taylor, ESA’s Rosetta project scientist, said in a statement.

“By happy coincidence, we were pointing the majority of instruments at the comet at this time, and having these simultaneous measurements provides us with the most complete set of data on an outburst ever collected.”

When astronomers reviewed the data, they reconstructed a chain of events leading up to the outburst, which they now think may have been the result of a landslide. Outburst signals grew by a factor of one hundred. Ultraviolet signals from the Sun were reflected from the center of the outburst cloud. The probe was blasted by grains of dust.

“From Rosetta’s observations, we believe the outburst originated from a steep slope on the comet’s large lobe, in the Atum region,” said Eberhart Grün, lead author of a paper published accepted for publication in the journal Monthly Notices of the Royal Astronomical Society.

“As a result, we think the outburst must have been triggered by a landslide at the surface, rather than a more focused jet bringing fresh material up from within the interior, for example,” he continued.

“We’ll continue to analyze the data, not only to dig into the details of this particular event, but also to see if it can help us better understand the many other outbursts witnessed over the course of the mission,” added Taylor. “It’s great to see the instrument teams working together on the important question of how cometary outbursts are triggered.”

This announcement comes just over a month before Rosetta is scheduled to meet its demise in a crash landing on the comet.

Editors' Recommendations

Dyllan Furness
Dyllan Furness is a freelance writer from Florida. He covers strange science and emerging tech for Digital Trends, focusing…
Largest comet ever discovered is 1,000 times the typical mass
This illustration shows the distant Comet Bernardinelli-Bernstein as it might look in the outer Solar System. Comet Bernardinelli-Bernstein is estimated to be about 1000 times more massive than a typical comet, making it arguably the largest comet discovered in modern times. It has an extremely elongated orbit, journeying inward from the distant Oort Cloud over millions of years. It is the most distant comet to be discovered on its incoming path.

The distant Comet Bernardinelli-Bernstein as it might look in the outer Solar System. Comet Bernardinelli-Bernstein is estimated to be about 1000 times more massive than a typical comet, making it arguably the largest comet discovered in modern times. It has an extremely elongated orbit, journeying inward from the distant Oort Cloud over millions of years. It is the most distant comet to be discovered on its incoming path. NOIRLab/NSF/AURA/J. da Silva

Comets are icy balls that orbit the sun and release gas as they approach the sun, giving them a distinctive tail. They are typically are 6 miles across, but scientists have recently discovered a mega comet that is 10 times that diameter.

Read more
This comet is a pristine visitor from the earliest days of the solar system
This image shows an artist’s impression of what the surface of the 2I/Borisov comet might look like.

This image shows an artist’s impression of what the surface of the 2I/Borisov comet might look like. ESO/M. Kormesser

Astronomers spotted an intriguing interstellar object in our skies in 2019: Comet 2I/Borisov, the second visitor from beyond our solar system after ‘Oumuamua. Now, new observations of comet 2I/Borisov show that it has likely never passed near to a star before. That makes it the most pristine comet ever discovered, and studying it could give clues to the makeup of the early solar system.

Read more
Hubble captures a wandering comet passing through the Trojan asteroids
NASA's Hubble Space Telescope snapped this image of the young comet P/2019 LD2 as it orbits near Jupiter’s captured ancient asteroids, which are called Trojans. The Hubble view reveals a 400,000-mile-long tail of dust and gas flowing from the wayward comet's bright solid nucleus.

NASA's Hubble Space Telescope snapped this image of the young comet P/2019 LD2 as it orbits near Jupiter’s captured ancient asteroids, which are called Trojans. The Hubble view reveals a 400,000-mile-long tail of dust and gas flowing from the wayward comet's bright solid nucleus. NASA/ESA/J. Olmsted/STScI

Both comets and asteroids are objects orbiting the sun, but comets are made of dust and ice while asteroids are made of rock, which means they have very different properties and appear differently in the sky. But there are rarely-spotted objects called centaurs which are a little bit of comet and a little bit of asteroid -- hence their name after the mythical creatures which were half human and half horse.

Read more