Previously on SPACE-FRIDAY Nine and a half years after the launch...
...the first human space probe flyby Pluto.
Pluto,...
...long time called the unknown final frontier of our solar system,...
...uncovered its look and design to humanity in 2015.
On August 28, 2015,...
...Ultima Thule was chosen as the next flyby target.
Today we are following New Horizons journey through the Kuiper belt...
...to Ultima Thule.
During his travel New Horizons continues to study the gas,...
...dust and plasma composition of the Kuiper Belt.
Ultima Thule was discovered on 26 June 2014 by astronomer Marc Buie...
...using the Hubble Space Telescope as part of a search for a Kuiper belt object for the New Horizons mission.
Ultima Thule was soon been renamed...
...as the nickname was criticized due to its use by Nazi occultists...
...as the supposed mythical origin of the Aryan race,...
...aside from its use in ancient Greek and Latin literature.
It’s now named: Arrokoth.
“The name 'Arrokoth' reflects the inspiration of looking to the skies...
...and wondering about the stars and worlds beyond our own”, explained Alan Stern.
After wake up from hibernation mode and verification of its health status...
...New Horizons official approach phase began on August 16, 2018.
On January 1st 2019, 4 years after the Pluto flyby,...
...the flyby to Arrokoth became reality.
Scientists waited 6 hours till a radio signal confirmed the successful encounter.
Arrokoth is the first Kuiper Belt object that is investigated by a close scientific research.
The majority of the science data was collected within the first 48 hours.
Priority data was sent back to Earth immediately after the approach.
The downlink is estimated to take 20 months.
New Horizons encountered Arrokoth within 3 500 km,...
...which is three times closer than the encounter with Pluto.
Arrokoth's geology is very exciting for scientist.
His spectrum exhibits a strong red spectral slope extending from red to infrared wavelengths...
...as New Horizons' LEISA spectrometer measured.
Arrokoth is 36 km long and shaped of two lobes attached by a bright, narrow neck.
The appearance of the surface is lightly cratered and smooth.
Both lobes were likely once two objects that had merged in a slow collision.
The lobes are 21km and 15km long with a diameter of 15.9 km and 12.9 km.
Each lobe’s surface shows regions of varying brightness along with various geological features,...
...originated from the clumping of smaller planetesimals, such as troughs and hills.
Deposition of material that have rolled down from hills...
...are thought as reason for the brighter regions as surface gravity on Arrokoth is sufficient for this to occur.
Stereographic analysis has shown that one particular subunit located at the large lobe's limb...
...appears to have a higher elevation and tilt compared to other subunits.
Topography variations at the limb suggest that its interior is likely composed of...
...mechanically strong material consisting of mostly amorphous water ice and rocky material.
Methane and other volatile gases, trapped in water ice, have also been revealed by LEISA.
Because of the structure of the two lobes...
...a definitive mass and density estimate cannot be given as the two lobs are in contact.
The full volume of Arrokoth is around 3 210 cubic kilometers (km³).
Scientists expect an estimated density between 0.29 grams per cubic centimeter (cm³) and...
...1 gram per cubic centimeter (cm³).
Tholins, a mix of complex organic compounds...
...are responsible for the red coloration as they are thought to have been produced from...
...the photolysis of simple organic compounds and...
...volatiles irradiated by cosmic rays and ultraviolet solar radiation.
A positive surprise was the exploration of solid methanol, created out of water molecules on the surface.
Solid methanol has so far only been detected on a few objects in the outer solar system.
Nevertheless Methanol, acetylene, ethane, and hydrogen cyanide are fewer volatile materials on the surface.
The internal structure is expected to be porous,...
...as volatile gases trapped in Arrokoth's interior are thought to escape from the interior to the surface.
The radioactive decay of radionuclides assume that Arrokoth may has an internal heat source.
Like Voyager 1 and 2,...
...New Horizons will continue its journey through the Kuiper belt...
...after the flyby at Arrokoth.
The expected end of the mission in 2021...
...will not be the end as New Horizons will become an artifact of human technology...
...long after humanity's existence has become stardust…