NASA’s New Horizons detects dusty hints of extended Kuiper Belt

New observations from NASA’s New Horizons spacecraft indicate that the Kuiper Belt — our solar system’s vast, distant outer region containing the building blocks of thousands of icy, rocky planets — may be more widespread than we thought.

Speeding past the outer edges of the Kuiper Belt, about 60 times farther from Earth than the Sun, the New Horizons Venetia Berni Student Dust Counter (SDC) instrument is detecting more than expected levels. The dust-Small frozen remnants of collisions between large Kuiper Belt Objects (KBOs) and particles ejected from the KBOs are peppered by microscopic dust impactors from outside the Solar System.

The readings contradict scientific models that the KBO population and dust density should begin to decrease within a billion miles of this distance, and contribute to a growing body of evidence that suggests the outer edge of the Main Kipper Belt. may extend billions of miles further than current estimates. Or that there could be another belt beyond that that we already know about.

The results are displayed. Astrophysical Journal Letters.

“New Horizons is making the first direct measurements of interplanetary dust far beyond Neptune and Pluto so that every observation can lead to a discovery,” said Alex Donner, lead author of the paper and a graduate student in physics at the University of Colorado Boulder. said As SDC Lead.

“The idea that we may have detected an extended Kuiper Belt—with a whole new population of objects colliding and creating more dust—resolves the mystery of the solar system’s most distant regions. offers another clue in doing so.”

Designed and built by students at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder under the guidance of professional engineers, the SDC provides new horizons as well as microscopic observations of collisions between asteroids, comets and Cooper Belt objects. Dust grains are detected. A 5-billion-mile, 18-year journey through our solar system—which included a historic flyby of Pluto in 2015 and KBO Urukoth in 2019—after its 2006 launch.

First scientific instrument on NASA Planetary Mission Designed, built, and “flown” by students, the SDC counts and measures the size of dust particles, which produces information about the collision rate of such bodies in the outer Solar System. .

The latest, surprising results were compiled over three years as New Horizons traveled 45 to 55 astronomical units (AU) from the Sun — with one AU being about 93 million miles, or 140 million kilometers, between Earth and the Sun. Is.

The readings come as New Horizons scientists, using observatories like Japan’s Subaru Telescope in Hawaii, have also discovered KBOs far beyond the traditional outer rim of the Kuiper Belt. This outer edge (where the density of objects begins to decrease) was thought to be about 50 AU, but new evidence suggests that the belt may extend to 80 AU or even further.

As the telescope observations continue, Donner said, scientists are looking at other possible causes of the SDC dust readings. A possibility, perhaps less likely, is Radiation pressure and other factors that drive the dust produced beyond 50 AU in the inner Kuiper Belt. New Horizons may also encounter short-lived ice particles that do not reach the inner parts of the Solar System and have not yet been accounted for in current models of the Kuiper Belt.

“These new science results from New Horizons may be the first time a spacecraft has discovered a new population of objects in our solar system,” said New Horizons principal investigator Alan Stern of the Southwest Research Institute in Boulder. “I can’t wait to see how far this elevated caper belt dust level goes.”

Now in its second extended mission, New Horizons is expected to have enough propellant and power to operate beyond 100 AU from the Sun until the 2040s. Beyond that, SDC could also potentially record the spacecraft’s transition into a region where dark matter dominates the dust atmosphere, mission scientists say.

Along with complementary telescope observations of the Kuiper Belt from Earth, New Horizons, as the only spacecraft to operate in the Kuiper Belt and gather new information about it, will have information on KBOs, dust sources, and A unique opportunity to learn more about the belt expansion, and the interstellar system. Dust and dust disks around other stars.