- 4399 - KUIPER and KEPLER - asteroid hunters at work? - The Kuiper Belt is much bigger than we thought? The New Horizons spacecraft is just over 8.8 billion km away, exploring the Kuiper Belt. This icy belt surrounds the Sun but it seems to have a surprise for us.
-------------------------- 4399 - KUIPER and KEPLER - asteroid hunters at work?
- It was expected that New Horizons would be
leaving the region by now but it seems that it has detected elevated levels of
dust that are thought to be from micrometeorite impacts within the belt.
-
- This suggests perhaps that the Kuiper Belt
may stretch further from the Sun than we thought! The Kuiper Belt is found beyond the orbit
of Neptune and is thought to extend out to around 8 billion kilometers. Its
existence was first proposed in the mid-20th century by Gerard Kuiper. It’s home to numerous icy bodies and dwarf
planets and offers valuable insight into the formation and evolution of the
Solar System.
-
- Launched by NASA in January 2006 atop an
Atlas V rocket, the New Horizon’s spacecraft embarked on its mission to explore
the outer Solar System. The primary objective was to perform a close flyby of
Pluto, which it did 9.5 years after it launched, and continue on to explore the
Kuiper Belt.
-
- New Horizons completed its flyby of Pluto
in 2015, and has been traveling through the Kuiper Belt since. As it travels
through the outer reaches of the region, almost 60 times the distance from
Earth to the Sun, its Venetia Burney Student Dust Counter (SDC) has been
counting dust levels.
-
- Throughout New Horizon’s journey, SDC has
been monitoring dust levels giving fabulous insight into collision rates among
objects in the outer Solar System. The
dust particle detections are thought to be frozen remains from collisions
between larger Kuiper Belt Objects (KBOs).
-
- These results were a real surprise and
challenged the existing models that predicted a decline in dust density and KBO
population. It seems that the belt extends many billions of miles beyond the
current estimates or maybe even that there is a second belt!
-
- The results came from data gathered over a
three year period during New Horizon’s journey from 45 to 55 astronomical units
(where 1 astronomical unit is the average distance between the Sun and Earth).
-
- While New Horizon’s was gathering data
about dust, observatories such as the 8.2-meter optical-infrared Subaru
Telescope in Hawaii have been making discoveries of new KBOs. Together these findings suggest the Kuiper
Belt objects and dust may well extend a further 30 AUs out to about 80 AUs from the Sun.
-
- New Horizons is now in its extended mission
and hopefully has sufficient power and propellant to continue well into the
2040s. At its current velocity that will take the spacecraft out to about 100
AU from the Sun so the research team speculate that the SDC could identify the
transition point into interstellar space.
-
- “Kepler”
is another mission that is enabling the discovery of thousands of
exoplanets, revealing a deep truth about our place in the cosmos. There are more planets than stars in the
Milky Way galaxy. The road to this fundamental change in our understanding of
the universe.
-
- Astronomers had assumed the existence of
exoplanets when the mission concept that would become Kepler was first
suggested in 1983. It wasn't until the 1990s that the first confirmations of
planets orbiting stars outside of our solar system were made, most of them gas
giants orbiting close to their host star, not at all similar to what we know
from our own solar system.
-
- When Kepler launched in 2009, fewer than 400
exoplanets had been discovered. Today, there are more than 5,500 confirmed
exoplanets and over half of them were discovered from Kepler data. Many of
these confirmed exoplanets reside in the so-called "habitable zone"
of their star, making them prime candidates for future observations to uncover
more of the universe's mysteries, including the potential for life.
-
- The Kepler mission was designed to address
the questions "How prevalent are other worlds?" and "How unique
is our solar system?"
-
- One of the technical changes made to the
1994 proposal before the 1996 submission included changing the orbit from the
Lagrange L2 point to a heliocentric orbit. This allowed Kepler to use reaction
wheels for pointing the spacecraft, which reduced the thruster fuel consumption
and saved on cost.
-
- The Kepler testbed proved that existing
charge-coupled device (CCD) technology no different from a consumer digital
camera could achieve the precision necessary to detect Earth-size planets in
the midst of the various kinds of noise expected in the whole system, from
vibrations to image motion to cosmic ray strikes.
-
- In the eight years between selection and
launch on March 6, 2009, the mission responded to a number of challenges and
changes that were largely beyond the team's control.
-
-
March 22, 2023 KUIPER and KEPLER -
asteroid hunters at work? 4399
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------ “Jim Detrick” -----------
--------------------- --- Saturday, March 23,
2024
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