The Kuiper Belt is much larger than expected

An artist's impression of a collision between two objects in the outer part of the Kuiper Belt. Such collisions are a major source of dust in the belt. Credits: Dan Durda, VIA

After giving us the first close-up images of Pluto in 2015, NASA's New Horizons probe has continued its journey to the edge of the solar system for nearly a decade, exploring the mysterious planet. Kuiper belt. And discover that moreover This region inhabited by thousands of asteroids and other small objects is much larger than we thought.

god Student dust counter from Venice Berni (Sdc) on board the probe reveals the truth Dust levels are much higher than expected. This instrument is the first on board a NASA planetary mission It was designed, built and operated “on the fly” by studentsIt is designed to count interplanetary dust particles and measure their size. In this way, it is possible to estimate the rate of collisions between the largest Kuiper Belt objects and the particles that rise from them following their collision with microscopic particles coming from regions outside the solar system.

From current models, the number of Kuiper Belt objects, and with them the resulting dust density, is expected to decrease at distances greater than 50 astronomical units – about 7.5 billion kilometers – from the Sun. But new data appears to contradict this prediction. : The Kuiper Belt could extend billions of kilometers beyond current expectationsThe planet is up to 80 astronomical units away from the sun – about 12 billion kilometers. It is possible that there is a second range, in addition to the already known range.

“New Horizons makes the first direct measurements of interplanetary dust beyond Neptune and Pluto, so every observation could lead to a discovery,” he comments. Alex DonnerPhD student in University of Colorado Boulderleads the sdc tool and first author ofpurpose appeared on Astrophysical Journal. “The idea that we have discovered an extended Kuiper Belt — with a whole new set of colliding objects and producing more dust — provides another clue to solving the mysteries of the far reaches of the solar system.”

The new results, collected by New Horizons at distances ranging between 45 and 55 astronomical units (i.e. between 6.7 and 8.2 billion kilometers) from the Sun, add to the recent results. Discoveries of Kuiper belt objects outside the traditional boundaries of this regionTelescopes are made like the Japanese Subaru In Hawaii. There are alternative, albeit less likely, explanations for the high levels of dust recorded by the Earth Observation Center: it is also possible that the Sun's radiation pressure is pushing dust toward the outer regions of the belt, or it may be shorter-lived ice. particles, which are not found in the innermost solar system and are therefore not included in normal models.

“This may be the first time a spacecraft has discovered a new group of objects in the solar system,” the co-author adds. Alan Stern, Principal Investigator New Horizons at the Southwest Research Institute in Boulder. “I can't wait to see how high these levels of Kuiper Belt dust get.”

The SDC instrument has detected microscopic grains of dust resulting from collisions between asteroids, comets and other Kuiper Belt objects along the entire path of the New Horizons probe since its launch in 2006. The mission, which is now in its second phase of expansion, must have enough fuel Working until the 2040s, reaching distances of up to 100 astronomical units (15 billion km) from the Sun, it can detect a transition towards a region of dust dominated by interstellar particles.

to know more:

• Read the article on Astrophysical Journal “New Horizons Venetia Burney student dust counter observes higher-than-expected fluxes approaching 60 AU“By Alex Donner, Mihaly Horanyi, Fran Bagnall, Pontus Brandt, Will Grundy, Carrie Lees, Joel Parker, Andrew R. Pope, Kelsey N. Singer, S. Alan Stern, and Anne Verbiser.