- 3919 - ASTEROIDS - how close to Earth? In 2019, for the first time, scientists have found the building blocks for life on an asteroid in space. Japanese researchers have discovered more than 20 amino acids on the space rock Ryugu, which is more than 200 million miles from Earth.
------------ 3919 - ASTEROIDS - how close to Earth?
- Scientists
made the first-of-its-kind detection by studying samples retrieved from the
near-Earth asteroid by the Japan Aerospace Exploration Agency's (JAXA)
Hayabusa2 spacecraft, which landed on Ryugu in 2018.
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- In 2019, the
spacecraft collected 0.2 ounce (5.4 grams) from the asteroid's surface and
subsurface, stowed it in an airtight container and launched it back to Earth on
a fine-tuned trajectory.
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- Rather than
being one large boulder, Ryugu is made up of many small rocks, and the asteroid
got its unusual spinning top shape from rapid rotation.
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- As a
carbonaceous, or C-type, asteroid, Ryugu contains a large amount of carbon-rich
organic matter, much of which likely originated from the same nebula that gave
birth to the sun and the planets of the solar system roughly 4.6 billion years
ago. Sample analysis has also suggested that the asteroid harbors water.
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- The sample collected from Ryugu was sent back
to Earth in an airtight container for analysis.
The Ryugu material is the most primitive material in the solar system we
have ever studied.
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- Unlike the
organic molecules found on Earth, the pitch-black asteroid samples, which the
scientists found only reflect 2% to 3% of the light that hits them, have not
been changed by interactions with Earth's environment, giving them a chemical
composition much closer to that of the early solar system.
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- These
prebiotic organic molecules can spread throughout the solar system, potentially
as interplanetary dust from the Ruygu surface by impact or other causes.
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- Sample
analysis detected 20 amino acid types.
Amino acids are the fundamental building blocks of all proteins and are
indispensable prerequisites for the existence of life on our planet.
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- A 2019
study found organic molecules from space in a group of 3.3-billion-year-old rocks
discovered in South Africa, raising the possibility that some of these
life-building molecules first came to Earth on comets and asteroids. The Ryugu
findings make the evidence that asteroids carry these molecules even stronger.
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- This means
that amino acids could likely be found on other planets and natural satellites,
a clue that life could have been born in more places in the universe than
previously thought.
-
- The
researchers are continuing to analyze Ryugu samples, and more data on the
asteroid's formation and its composition will become available soon.
-
- In 2021,
NASA's OSIRIS-REx spacecraft collected a rock sample from another
diamond-shaped asteroid, named Bennu. When the sample returns to Earth in 2023,
signs of organic matter contained within it could provide scientists with
important clues into the evolution of the solar system and its materials,
alongside how life emerged from them.
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- NASA's Dawn
spacecraft will rendezvoused with the asteroid “Vesta”. Most asteroids,
including Vesta, reside in the doughnutlike ring of the main asteroid belt that
peppers the space between Mars and Jupiter. Other asteroids whirl in tight
circles closer to the sun than the Earth, while a large number of them share
planets' orbits. Some asteroids' orbits
take them on planet-crossing swings through the inner solar system.
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- The biggest
asteroid by far is Ceres which explains why it was discovered first and it
makes up about a third of the asteroid belt's mass. The object is so hefty that
it's the only asteroid that has the gravitational strength to pull itself into
a sphere.
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- On account
of this roundness, Ceres is also considered a "dwarf planet," a
designation it shares with four other objects in the solar system, including
Pluto.
-
- After
scoping out Vesta, the Dawn spacecraft will journey on to Ceres, arriving in
2015. The object is probably the
"wettest" asteroid, with large stores of water in its interior as
ice, though also possibly as a liquid layer beneath the surface
-
- Baptistina is
the name of one of the youngest families of asteroids in the asteroid
belt. Families of asteroids are swarms
of objects that share orbital characteristics.
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- Baptistina
and its swarm were spawned some 160 million years ago by a smashup between a
37-mile-wide body body and another object about 106 miles in diameter. That
cataclysm created hundreds of large objects, some of which then drifted into a
collision course with Earth.
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- One or
several of these rocky shards of shrapnel then plowed into our planet 65
million years ago and helped doom the dinosaurs. The impact gouged out the
Chicxulub crater, now buried by the Yucatan peninsula and the Gulf of Mexico.
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- The
100-million-year Baptistina barrage did not spare the Moon, either. A meteorite
scooped out the giant Tycho crater about 109 million years ago.
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- Many
asteroids, believe it or not, have a moon, and some even sport two satellites.
Kleopatra has two moons, which were named Alexhelios and Cleoselene earlier
this year. The metallic asteroid has an unusual dog-bone shape.
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- The
asteroid is roughly 135 by 58 by 50 miles in length, height and width. Its
moons Alexhelios and Cleoselene are, respectively, about 3 miles and 1.9 miles in diameter.
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- Like
Kleopatra, Hektor is very elongated, with length and width dimensions of
approximately 230 by 124 miles. Hektor has a moon as well. Unlike Kleopatra,
however, Hektor is not found in the main asteroid belt; instead, the dark,
reddish body dominates as the biggest of Trojan asteroids stuck in Jupiter's
orbit.
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- These rocks
lurk in what are known as the L4 and L5 Lagrangian points two of the five zones
in an orbit where the gravity of two bodies ( Jupiter and the Sun) balances
out. L4 and L5 lie ahead and behind, respectively of Jupiter.
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- Themis, a
large main belt asteroid, stands out as the first and only asteroid known thus
far to have ice on its surface. In 2009,
observations in infrared light confirmed the presence of this ice, as well as
carbon-containing, or organic, molecules.
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- These
characteristics make Themis and similar bodies called main belt comets good
candidates for having delivered water and carbon some of the ingredients of
life to the surface of a young, hot, dried-out Earth some four billion years
ago.
-
- Named after
a Celtic god, Toutatis is one of the oddest asteroids. Instead of rotating in
an orderly fashion about an axis, the double-lobed object chaotically tumbles.
This unpredictable movement partially derives from Toutatis being composed of
two bodies barely in contact with each other and from the influences of both
Earth and Jupiter's gravity.
-
- Toutatis'
path through the solar system has it sweep close to Earth, but because the
asteroid's orbit is chaotic, its exact path and how close it might come to us
centuries from now cannot be well predicted.
-
- Like some
other asteroids, Toutatis is said to be a like a "rubble pile"
fragments of rock that have gravitational come back together after a collision,
but left many gaps between them.
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- Toutatis has
made some close shaves to Earth, and passed within 1,000,000 miles of Earth, or
about four Moon distances, back in 2004. Yet some rocks have made notably
closer passes, and the one that has most alarmed astronomers and the public
alike is Apophis.
-
- Discovered
in 2004 and named after the Greek word for the evil Egyptian god of darkness,
Apophis will return to the neighborhood in 2029. At the time, scientists
calculated that its impacting Earth on that future pass were as high as 1 in
40, but subsequent measurements have now relegated that possibility to almost
nil .
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- Panic peaked
in December 2004, and Apophis achieved a ranking of 4 on the Torino scale, the
10-point scale that rates the risk of an object colliding with Earth (10 being
an unquestioned apocalypse). Although Apophis is now deemed a 0 for its 2029
pass, it will zoom a mere 18,600 miles above Earth's surface.
-
- A number of
these other so-called Near Earth Objects, or NEOs, have yet to be cataloged.
Yet some that have pose no threat, and benignly share Earth's orbit. At least
four examples exist of asteroids that follow Earth in horseshoe-shaped orbits;
a new one, designated 2010 SO16, was found earlier this year.
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- An
experiment to bounce a radio signal off an asteroid on Dec. 27 will serve as a
test for probing a larger asteroid that in 2029 will pass closer to Earth than
the many geostationary satellites that orbit our planet.
-
- Astronomers
will transmit radio signals to asteroid 2010 XC15, which could be about 500
feet across. The University of New Mexico Long Wavelength Array near Socorro,
New Mexico, and the Owens Valley Radio Observatory Long Wavelength Array near
Bishop, California, will receive the signal.
-
- Longer
wavelengths can penetrate the interior of an object much better than the radio
wavelengths used for communication.
Knowing more about an asteroid’s interior, especially of an asteroid
large enough to cause major damage on Earth, is important for determining how
to defend against it.
-
- If you know
the distribution of mass, you can make an impactor more effective, because
you’ll know where to hit the asteroid a little better. Those radar-imaging programs use signals of
short wavelengths, which bounce off the surface and provide high-quality
external images but don’t penetrate an object.
-
- HAARP will
transmit a continually chirping signal to asteroid 2010 XC15 at slightly above
and below 9.6 megahertz. The chirp will
repeat at two-second intervals. The asteroid will be twice as far from Earth as
the moon is.
-
- The test on
2010 XC15 is yet another step toward the globally anticipated 2029 encounter
with asteroid Apophis. It follows tests in January and October in which the
moon was the target of a HAARP signal bounce.
-
- Apophis was
discovered in 2004 and will make its closest approach to Earth on April 13,
2029, when it comes within 20,000 miles. Geostationary satellites orbit Earth
at about 23,000 miles. The asteroid, estimated to be about 1,100 feet across,
was initially thought to pose a risk to Earth in 2068.
-
- NASA says
an automobile-sized asteroid hits Earth’s atmosphere about once a year,
creating a fireball and burning up before reaching the surface. About every
2,000 years a meteoroid the size of a football field hits Earth. Those can
cause a lot of damage. And as for wiping out civilization, NASA says an object
large enough to do that strikes the planet once every few million years.
-
- NASA first
successfully redirected an asteroid on September, 26, 2022 when its Double
Asteroid Redirection Test mission, or DART, collided with Dimorphos. That
asteroid is an orbiting moonlet of the larger Didymos asteroid. The DART collision altered the moonlet’s
orbit time by 32 minutes.
-
- The December
27 test could reveal great potential for the use of asteroid sensing by long
wavelength radio signals. Approximately 80 known near-Earth asteroids passed
between the moon and Earth in 2019, most of them small and discovered near
closest approach.
-
March 16, 2023 ASTREROIDS - how close to Earth? 3919
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