The outer part of the solar system turns out to be “dustier” than expected. Actual measurements of the amount of dust. Space portal website sorae

There are countless icy bodies like Pluto outside the solar system.Edgeworth Kuiper BeltCreate a crowded situation. It is not known how far the Edgeworth Kuiper Belt extends, but previous predictions had predicted that the density of celestial bodies would begin to decrease at a distance of more than 7.5 billion kilometers from the Sun. In this case, the amount of dust in the space should also be less.

However, a research team including Alex Donner of the University of Colorado Boulder discovered that NASA's Pluto rovernew HorizonsAfter analyzing the monitoring dataThere is hardly any dust drop after the expected distance.I discovered it. This result suggests that the Edgeworth Kuiper Belt may extend further than expected, or that there may be another Edgeworth Kuiper Belt out there.

■كم عدد الأجرام السماوية الموجودة خارج المجموعة الشمسية؟

ومن المعروف أن هناك عددًا لا يحصى من الأجسام الجليدية مثل بلوتو خارج نبتون.المنطقة التي تتوزع فيها هذه الأجرام السماوية تحمل اسم كينيث إدجوورث وجيرالد كويبر، اللذين تنبأا بوجود مثل هذه الأجرام السماوية وحزام الكويكبات بين المريخ والمشتري، ويسمى “حزام إدجورث كويبر”، والجسم نفسه يسمى “حزام الكويكبات” “جسم حزام إدجورث كويبر”(※).

*…ومع ذلك، فإن وجود وتوزيع الأجرام السماوية التي تنبأ بها إيدجورث وكويبر يختلفان بشكل كبير عما هو معروف حاليا، وهذا الاسم محل خلاف. في الآونة الأخيرة، على الرغم من أنهما ليسا متساويين تمامًا، فقد كان هناك ميل لاستخدام مصطلح “جسم عابر للنظام الشمسي” كمصطلح مرادف ومحايد تقريبًا. سنشير إليه في هذه المقالة باسم حزام إيدجوورث كويبر، لأنه تعبير سهل الفهم يشير إلى بنية مكونة من أجرام سماوية متعددة، ولأن هذا المصطلح مستخدم في الورقة الأصلية.

من الصعب مراقبة حزام إيدجوورث كويبر، الذي يقع بعيدًا عن الشمس، وقد مضى حوالي 30 عامًا فقط منذ أن أصبحت المراقبة واسعة النطاق ممكنة. ولذلك، لا يزال من غير المعروف مدى انتشاره.

One of the things crossing the Edgeworth Kuiper Belt, an empty zone for scientific research, is NASA's Pluto probe New Horizons. New Horizons, which conducted the world's first close-up exploration of Pluto, has since undertaken several expanded missions. One of them is “Particle counter for students Venice BarneyIt measures the amount of dust in the outer solar system using the Venetia Burney Student Dust Counter (VBSDC).

VBSDC is the first observing instrument to count dust particles far beyond the orbit of Uranus, allowing us to obtain information that no one knew before. For example, dust is generated when celestial bodies collide with each other, so by measuring the amount of dust we can indirectly know the amount of celestial bodies.

■It turned out that the amount of dust did not decrease as much as expected.

Donner and his team analyzed New Horizons' VBSDC observational data and the amount of dust measured between 6.8 billion and 8.3 billion kilometers from the Sun, much farther than Pluto. Previous studies predicted that the decrease in the number of objects in the Edgeworth Kuiper Belt will lead to an edge in which the amount of dust decreases from a distance of about 7.5 billion kilometers. If things go as expected, we should see a reduction in dust in this analysis.

However, in this analysis, it was found that almost no reduction in the amount of dust was observed within the measured area. Based on dust measurementsIt is certain that the Edgeworth-Kuiper Belt extends over an area of ​​approximately 9 billion km, and its actual edge is estimated to extend over an area of ​​approximately 12 billion km or more.Alternatively, the Edgeworth-Kuiper Belt may not have a single belt structure, but rather one inner belt and one outer belt.

The above explanation is just a hypothesis, and there may be other reasons for the abundance of dust. For example, solar radiation or another cause may be able to efficiently transport dust farther than about 7.5 billion kilometers. Alternatively, it is possible that short-lived ice grains are produced that cannot be predicted by current models.

However, Donner and others believe that these alternative explanations are unlikely to be correct. In fact, some telescopes, such as the Subaru Telescope, have detected many objects far beyond the traditional Edgeworth Kuiper Belt. The results of this analysis confirm that there is a high probability that there are countless crowded celestial bodies outside the solar system.

New Horizons on its second extended mission.Observations are scheduled to be conducted at a distance of about 15 billion kilometers from the Sun in the 2040s.If the amount of dust could be measured even at this distance, we would be able to tell whether the edge of the Edgeworth-Kuiper Belt estimated in this study actually exists.

source

• Alex Donner, et al. “New Horizons Venice Bernie student dust counter observes higher-than-expected fluxes approaching 60 AU”. (The Astrophysical Journal Letters)
• NASA Communications. “NASA's New Horizons Discovers Dusty Hints of Expanding Kuiper Belt”. (NASA)

Written by Riri Aya